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yÅ8 3 1 ÝÞ ÈT3 n 0 ÝÞ È Ω Æ0 o Ω = (a , · · · , a ) | a = 0 ® 1, j = 1, 2, 3, 4, 5 . @ ¥ :à} 32 :/0:ç 0 ® 1 å 5 }A* :[ Å8Ùä! ω ®"#}$ä! ω ÝÞ Ω @ *T
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1
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ywyyxyzy{y(3)|y}y|y~y}yyyyyyy
yy (1)10yyyyy yΩ;y (2) |y}yyyyyyyy 2. yyyyy y¡y¢y£ ¥¤Ey¦§¨y
(1) yyy Ω; (2) ©y§yyyªy ¡yy«y¬yyyy r(®y¯ 0 < r < 1) yy yy (3) ©y§yyyªy y¡y«¬° y yy 1.
1 3
1 2
±a²a³a´ >? ><G JKCµA ?¶· ýý¸ = F Å 8 r Ü 4 5 : Ò e ] Z k < = ¹þÿBC º»¼ = F¹BCK½¾¿ * W~Ò~<~= >~?0À I00Á~Ï~
Å~8~¿Â~k~~¼½0k~Ï~¼½0k¹ ºT--* 4@jÅGÆ5K
1 n
m n
P (A) =
,
(1.2.1)
¥ @ |A| |Ω| ÊËÝÞq S A Ω @ uqrk[\q S (7\- ) A*+WX E ÌÍÆÔIÏÎÐÑÒ* ÓÔ E Í0:Xe]Zk E ÌÍ*TÅ8ÜÕ: º* Ö 1.2.1 :ß¼½k¹Gº:×T
G<=Gq S k\GN E G (1) Ok-A;è 5; (2) Ok-AIØA) (3) Ok-AIÙA* Ú ÊËÙ A, B, C ÝÞdÛ<=q S ×ÜÁ 6}, B = {2, 3, 5}, C = {2, 4, 6}, Ý 6 |A| = 2, |B| =A 3,= {5, |C| = 3, çè |Ω| = 6, u3ç#Þ (1.2.1) ß 2 6
= 13 ,
|Ω|
3 6
= 12 ,
3 6
= 12 .
Ö 1.2.2 :ß¼½k 3 ×T
q S k\N E (1) 3 / ~O~~~) (2) à~} 1 ~~O~H~~) (3) á 1 ~~O~H~0× U0â0T~}~~~OH~* P (A) =
P (B) =
P (C) =
ì íî ïðñò Ú Å8rÜãä7\^_ Ω 0å*æçè× Ω Ì`ç:é^o\Nk [\<=q S uå×Äç 3 u^oO > ku};Íxyuå×Tá â Ω = {(H×TH×TH ), (H×TH×T ), (H×T×TH ), (×THê×TH ), (H×T×T ), (×TH×T ), (×T×TH ), (×T×T ) }.
au_× h ^3Ù 1 ÝnÞH×TÙ 0 ÝÞ×Tè0 h ^oã Ω ÝÞI Ω = (a , a , a ) | a = 0 ® 1, j = 1, 2, 3 . ökÅ8/} |Ω| = 8. ËÌ[×T
yÊËÙ A, B, C ÝÞdÛ<=q S ×ë} A = {(0, 0, 0)}; B = {(1, 0, 0), (0, 1, 0), (0, 0, 1)}; C = {(1, 1, 1), (1, 1, 0), (1, 0, 1)}. Ý 6 |A| = 1, |B| = 3, |C| = 3, çè |Ω| = 8, u3ç#Þ (1.2.1) ß 4
1
2
3
P (A) = 81 ,
j
P (B) = P (C) = 83 .
3 dì/0e]h Zk ÓÔ E Íkl º×T¥ @ k7(@ \^_ Ω <=q S /íÜäO×7\-kA íS ÜOE*n6 êl Aîì ×{;*W0]Z* çè~Å~80k E Èk~0~Õ0ï~<~=~q k~\~N 0× 6~; è~ä~SO070\0^0_k~S v~wðí* 6HñÕï l k+ò0Hñß7\^_ Ω <=q k[\S q kA×Tu 3óôÅ8 Êìæ×T^3;lææGS ä@ O(7\(^_ S Ω <=q kvwjí×T6 1Hñß7\^_ Ω <=q k[\q kAÄ^*Õõº* Ö 1.2.3 10 ö 4 ÷<=[øå:«×T¦sù÷ú/;Ëûk E * Ú ÁÅ8 10 ö 4 ÷à 14 ©øå:«ku};Í°ü*7\^_ Ω çu };Í°üå×Tu3 |Ω| = 14!.
yÙ A ÝÞ¦sù÷ú/;Ëûkq S ×ëq S A ç:éýþ1ÿÆk° üå*Å8rµ 10 ùöú<=[øå:«× µ 4 ù÷ú;Ëû[ ¥ _×Ä 4 |A| = 10! · C11 · 4! =
10!·11! 7!
,
çè “ < =[øå:« ” ÝÞX;Í°ü0-^ok×Tu3 P (A) = = . Ö 1.2.4 Ý 5 ~;~Í0k~º @ <~= ó 4 0× ÿ~
~q S k~\~N E ~ q S A: 4 ~º @ ¦0s~~~;~å~) q S B: }~~~å0× ~~~;~å~) q S C: 4 ºàå * Ú Ý 10 º @ <= ó 4 × à} C = 210 X;Í ó ü×Ut |Ω| = 210. l q S A @ × 4 ºÊË ó g 4 X;Í k º * 4 X k º l ó @ } C = 5 X~^~o~* ~Ë~â Ì 0k º ÊË O 1 ~* 1 (0$~Ç~0 0$ )? à} 2 = 16 X^o*Tá |A| = 5 × 16 = 80. l q S B @ ×T} 1 G ó O(×T} C = 5 XG^GoG)TÇG}G º G G [ G⺠ó ó Ê(Ë O 1 ( × G O 1 } C · C · C = 24 XG^GoG*Tá 10!·11! 7!·14!
30 91
4 10
4 5
4
1 5
2 4
1 2
1 2
§1.2
mnop
5
l q S C @ ×T}º[ ó O×T} C = 10 X^o×t |C| = 10. ÛdÛ×T = = , P (B) = = , P (C) = = . l 3dP (A) @ ì ×uÙk°×ÛÕh AÌÞ0êuk×S~Usæ Ù°ÌÞÕA ×sæ E ÙÛÕAÌÞ× /Û ×Øk * z0Å~8kÉÈ S k ÕïE <=q \Nk ×6;0ÕA*Å8 !ê § k~º×7 " 0 OJ Ö Õï#$%kÕAîìk_k&@ Ë* 1.2.5 : 'º (+V 10 )×¥ } 7 + *,)× 3 -)*Ñ ',P ./ :+ 0j × ßo 1O 1 ) * )8 2r 3S ô[ 451*+
y 10 )/ 1 OJ'º×T3 A ÝÞá k O'k)0-)kq ×T±ÿ |B| = C51 · 24 = 120.
2 5
80 210
8 21
120 210
4 7
10 210
1 21
k
1, 2, · · · , 10. Ú6 1: 10 )O'krPô(A7),àk} = 10! l S X ; Í ^ o T × u 3 |Ω| = 10!. q @ ×á k O'k)0-)× 1 -)Á} C = 3 X^o× l ¥8 9 ù A 9 d)8^¦§°×T} 9! X^ok7×Tu3 |A | = 3 · 9! . t} l d(ÛGÊ(ü @ ×TÅGP8G(AÑ )10= )=:GI , 10kG=;G1,Í(2,(· · (· , 10. × l Õ(ïG7G8GO'(kGr(ô 7æ;× ÙJ ° ÌÞÕA*z0 )8}æ0 <é =Ëk;× >J ?@Üè AÊ B 5( × UCW?X@GYËGZ Í( k )B( _ 44
1 3
k
k
k
3·9! 10!
3 10
]^_O` a ]{ fg@Ohij ]O^_ klmnopq10rs[\ T b Gut Iiv \wxy\z ^_O`a|}J~DLN r RGMv
2: Cf\]O^_ Tr f 7 [ (7 +,h ), r f 3 [ (3 T KM C f X O`aR ( m h ),s t,\z b{ ^_OT` a | } [Fh s [F+,h T ). |Ω| = C = 120. C A T Z k DNOm hF h (y\ ¡ F 1 h ), C¢£ 9 [[ h ( ¡ F [ ), |A | = C = 36, HI¤ P (A ) = = , k = 1, 2, · · · , 10. ¥¦§¨ OF©zªxy«f\]OJ¬|}J~ |Ω| |A |, ®FJ~D ¥± F b² OG³´µM T·¶¸¹º»¼½¾¿ÀÁ¹û¼ GÄ O ¯ ° ¶¸¹º»¼ÅTÆǽÈÉÊË̹ÃÍÎϹºÐÑÒÓÔÕÖ×ØÅ ÐÑÙ (Ú Ñ×Ø ) ÂÃ+Û,TÜÈÇÝÞßàáÉʾâ̹ÃÍÎ G;ãä m§¨ Xåræ xy r fJ¬|} T;å ræ xy r fJ¬|}G;çèé O F ; © \ Sê OJ~ëìvíîIGðïîñòó T;ô õöhöN÷øO¢Kùú© 3 10
3 10
k
k
k
36 120
3 10
k
2 9
û ü,ý þÿ + 3: t î m ö k öNOhFhO¯° T òó k r öN O h O ` a
G Ω «+t 10 (\]O ) h ö k hvO T k öNOhFh T X O`aX} T T |Ω| = . A C = 3 f ¢XO k − 1 T [F t ¢£ 9 (\L]O ) h ö r . k − 1 hvO O`a} |A | = 6
10! (10−k)!
k
1 3
k
3·9! 10!
3 10 ,
3·9! (10−k)!
T ¦ «fùú b ]OG ³[!"´µM© ³ M å î#$ T éf\]Oùú T'&( xy\]OJ¬|}J~ ¯ % ÷ ø )* O[¬G ® + W å ),- ./xy b ]OJ¬|} T0&(X1 õö pq Où2G 3 I 45 T ³[÷øO67 Tðô r [89 §;: 4<©ð\= k ² î> T ? P (A ) = , ² î ( ³[÷øOù6 @ A h h B D O C !
G E FyîG r [÷ø© H 1.2.6 10 IJ 3 IKL T 7 IKM OT N KLO J Z JG 10 [ 9 PQ N J T R 9O J¯°G T x T© S [ N J O 9 J O U V A , k = 1, 2, · · · , 10. \ W i ö yø Oùú TX ö |Ω| |A |, YE P (Ak ) =
k
=
k = 1, 2, · · · , 10.
3 10
k
k
36 120
3 10 ,
T e½fghi ^ TÅ _ ¶¸jklTmj ³ [ [Z \ ] ^ _ ` a b c d l¿no _Äpa_ Å prq Âs H G0t+ N J uO³fvwx T'y K N q = y z{| yG Z M}vi [ ~ O !"G H 1.2.7 Y X 1, 2, · · · , 9 O 9 I O
I T I ¬4 \ î 10 O¯°G ©ð A U I ¬ 4 \ î 10 O T MPvJ~ |A|. T X a b O¬ T I + P Q ö O I z
a b + 1, 2, · · · , 9 O[\]O¬ G U a + b = s, s ≥ 3. Pi s = 2k − 1 O © 1 + (2k − 2) = 2 + (2k − 3) = 3 + (2k − 4) = · · · = (2k − 2) + 1 = 2k − 1, r 2k − 2 [ a + b = 2k − 1 OR¬ å (a, b), &( ¢ ? a 6= b. }i s = 2k O ut,î 1 + (2k − 1) = 2 + (2k − 2) = 3 + (2k − 3) = · · · = (2k − 1) + 1 = 2k, r r Z a = b = k, 2k − 1 [( a + b = 2k Oå R¬ å (a, b), ®+¢ a + b = 2k a 6= b OR¬ (a, b) Z 2k − 2 [ P (Ak ) =
=
k = 1, 2, · · · , 10.
§1.2
(§ ¨ s ≥ 3), ¦ |A| = 2(2 + 4 + 6 + 8) = 40. S tîM S ~ |A| r« IT + z PQ
öO T òó«PQR T ] YE ~ |Ω| ¤ = 9 × 8 = 72. (r I 9 f ú T I|Ω| 8 f
ú ).
å
7
k = 2, 3, 4, 5
40 72
= 59 .
) ø ô ¢Kùú T æ \; ¡ r H 1.2.8 ¢ G +uGñ}O£¤¥O¦¬ P (A) =
g(x)
O§ p ©
g(0) = 0,
¢ T α = 1 ¨ −1. ~T / © ª§ p O¦¬«Y ./¬
r [¦ ¬ . / A O¯° ¢ A Z® å
¥ öO¦¬ g(x) îwG"§© G = {g| g(n) = k}, k \¯° n O±¬ ©²³ Ω \]O
ú T ´µ |Ω| ² î G O¦¬[¬ t î G · O ¶ r · [ ¦L¬ ? r [L¬ (α , α , · · · , αT ´) µ bLå T E α = 1 ¨ −1, j = 0, 1, · · · , n − 1. ¸ G 2 [\]¦¬ |Ω| = 2 . T
öO¦¬ g(x) ¹ g(n) = k. E+t ¦¬ g(x) O º T./g(j+ 1)A= g(j) + α , g(x) = g(j) + αj (x − j), j ≤ x ≤ j + i, j = 0, 1, 2, · · · , n − 1,
j
k
k
k
0
1
n−1
j
n
n
k
j
g(n) =
n−1 P
(g(j + 1) − g(j)) =
n−1 P
αj .
t,î¶[ α ? + Z 1 ¨ −1, ¸»U¬ (αST , α , · · · , α ) O 1 O[¬ Z a, U¢ ³ T A ¼ O −1 O[¬ b, ½ T ³ a − b = k, a + b = n,ST W X Z a= . t,î a 1 O[¬ b S±T ¬ ³ k n O´¾µ¿x¦ \] |A | = 0; E³ k n O¾¿x ] |A | = C . ( 0, w k n O¾¿x\ ] ; P (A ) = b C , w k n O¾¿x ] . À ° ñ> [! ø T ÁÂÃÄÅ «#$ ¯% O¯ÆÇ ¢ùú T'È ¬ «ùø S OÉ ) T &(ôÊ « ¬ úOéx Ë ¼ 1.2 1. ÌÎÍÎÏÎÐÎÑÎÒÔÓÎÕ×Ö “ØÎÙÎÚÎÛÎÜÎÝÎÞÎß×à 3” ÚÎáÎâÎã 2. ä 5 åÎæÎçÎèÎéÎÚÎêÎÑÎë×ì×í 4 îÎÒÔÓÎïÎðÎëÎñÎòÎó 2 îÎôÎõÎöÎåÎÚÎáÎâÎã 3. ÷ÎëÎó 9 øÎùÎÒ 4 ø ú'ùÎÒ 5 øÎûÎùÎÒüÙÎäÎëÎæÎý þ' ÿ ×íÎÍ×øÎã ×Ó (1) ÍÎø ú ùÎÚÎáÎâ (2) ÎùÎö ú'öÎûÎÚÎá×â (3) ñÎòÎóÎöÎøÎûÎùÎÚÎá×â×ã 4. ÎèÎ í×ö×ø Îè×é×Ò Ó ×ø×Ü ×æ×çÎÚ×á×â×ã (ÎøÎÜÎëÎÚ öÎø Îßé ÎÎëÎÿ×ì× í 0, 1, 2, · · · , 9) j=0
j
0
1
j=0
n−1
k
n+k 2 k
k
k
1 2n
n+k 2
n
n+k 2
n
8
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Îø Ü;ÎëÎæ<=ÎÿÎì×í 4 øÎÒÔÓÎïÎð>Îõ×öÎø 4 ?@ÎÜÎÚÎáÎâÎã 8. 1,2,3,4,5 -ÎøÎÜÎëAÎ ì B×íÎö×ø×ÒDC E$×Ú×ø×ëF×í×öÎø×ÒDGHI 20 øJÎóKÎçÎÚÎáÎâÎãLÎÓ#$%ÎÕÎÖ×ÚÎáÎâ ó×öÎøMÎÜ (1) NÎöOPQ (2) N OPQ (3) Í OPQÎã 9. RÎöÎÏSÎÚ12Î" Ò TQ×ï UV×Ø×ÙÎÍ OK×çÎÚ WXYÎ"Ò Z[\]^_`×"Ò a×Ó $b ÕÎÖÎÚÎáÎâ (1) c RNdOÎÝ eWf (2) ghR@ÎÜ OiWf×ã 10. Îöjklm (52 nÎÒ æ opqrsm ) ëÎìÎí 4 nÎÒ Ó (1) nmtuÎæ K×çÎÚ×á â (2) nmtuÎæ KÎç×Ú×á×âÎã 11. vwxyÎó 12 ø ?z>ÎõÎö bÎ"Ò ×Ó ó 8 ø ?zw{xÎ"Ò |_}×Ú 4 ø ?zU Îö ~ ÚÎáÎâÎã 12. `×ó 10 }×ä 1 Q 10 è×Ú
×ÒÔÙ×ß ×ÿ×ì 3 ø×æ×ç×Ú &×Ò 3
Îø ÚÎ&×è×"Ò éÎ.Dã × Ó (1) rÎèÎé 5 ÚÎáÎâ (2) qÎèÎé 5 ÚÎáÎâÎã 7.
13. 14.
ä
ÚÎáÎâÎã
0, 1, 2, · · · , 9
:
10
3 " 7 ¡15¢£¤¥ 10 6 9 ¦§¨ n n n £©ª «¬ m ® "n±©¯¢£° ²m³, m, m2r(m(2r+<mn) +m"=´m)µ¶·£¸¤¹¥£ ¤¥º (1) »¼±£² ³ (2) ±²³ (3) ½ ±²³ (4) r ±²³ ¾¿À£ÁÂÃÄÅ´ºÆÇ¿ÀÈÉ 1 Ê 33 ©Ë̬ 7 §ÍÎÏÐÑ Ó 7 §ÔßÕà ÖקØÖ (Ù©ËÌ ), ¿ÀÖßÚà ÅÛÜÔÕÖÝÞ ßÏàÒ¦ (©1á∼â33ã ),Î ° æ äÏ ßà 5 §ÔÕäÖÏ× ØÖ6§°ÔçÕäÖÏ×Øè¯Ö"É °Aå,äAÏ, A , A é6 §ê ÔÕÖå"° æ "çäÏ£¶·Dëìí£¤¥ 1
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æjçmè éêëì 1§A A F µ B ;F67-JKs ' A ⊂ B ÜÝ A Öíîï B ð¼ñ A ⊂ B òó A ôõ 8 B. Ijim A ö÷ B, B ö÷ À % A ⊂ B, ¦ B ⊂ A, V
7 A = B. -ø imù 9 · W£úAø i ÷ / <û 9 ¶ ö÷ âA,ã 6 ; Èü^û 45 xýþÿ ; N A , A , · · · , A n t S A ∪ A ∪··· ∪A ~ A , '
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1 n
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n
n
n
1
2
k
n
k=1
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1
2
n
2
A1 ∪ A 2 ∪ · · · =
∞ S
n S
Ak = lim
Ak ,
I_ A , A , · · · ' ÉÊ T( U µ*)+T,-. ' A ∩A ∩ ··· = A = lim A , I _ A , A , · · · y W ; È/0 wc /0 JKs ' ù1 AJà; öø÷2 fäå ÷ JKL=M; N {A , n ∈ N } $ ; } ¡¢ ȳ /0
T S S 1
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n→∞ k=1
k=1 ∞
2
n
k
n→∞ k=1
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k
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n
ω∈
∞
∞
⇒
An
1 È/0 /0
k=1 n=k
ω∈
∞ T ∞ S
∞ T
∞ S
ω∈
An
k=1 n=k
An
⇒
∞
I_
n=k
An , ∀ k ∈ N
⇒
{An , n ∈ N }
∃ k ∈ N, ω ∈
∞ T
∃ nk ≥ k, ω ∈ Ank , ∀ k ∈ N .
' 3456 ; 7 F³c ⇒
An ,
ω ∈ An , ∀ n ≥ k, n ∈ N .
1c /0 S T A I_ {A , n ∈ N } '98 5 ××: 6 ; cefäå È / 0 wc / 0 ; t f<; v S A ⊃ S 1 S A c= > $F67& > $?- /0 Fu¦
k=1 n=k
∞
∞
n
n
n=k
k=1 n=k
∞
n=k
∞
An ,
n=k+1
n
n=k
∞ S ∞ T
7
vm
∞
n
An = lim
k→∞ n=k
k=1 n=k ∞ T ∞ S
An = lim
' 0x “{A , n ∈ N } É k=1 n=k
n
∞ S ∞ T
An .
An .
Z ö ÷ ”
k→∞ n=k
“{An , n ∈ N }
' @A
kmlnojpmqr ”, 1 öø÷ á /0 : , HG §1.3
11 ∞ T
lim
k→∞ n=k
An
BDCE f > $
lim sup An =
á /0
∞ S
lim
BDCE f > $ n→∞
k→∞ n=k
An
lim inf An =
öø÷ áÀ È s$%$ {JI ' n→∞
K
L
Ω Φ ω A ω∈A
A⊂B A=B
~
A∩B
AB
AB = Φ A∪B Ac
A−B
~
AB
A4B
lim sup An n→∞ ∞ S ∞ T = An k=1 n=k
c
sLM M ~ () 0N () ω A ' A - B · A¥ B9 x 9 u Û t³ Û È/0
∞ S ∞ T
An ;
k=1 n=k
{An , n ∈ N }
∞ T ∞ S
{An , n ∈ N }
FG
IG : , H G
An .
k=1 n=k
JK sFLZM x 0 A, A " # $ % ω O A FV B µ(F A ö÷ B y( ÷y W ~ y W x A¥ BG I_ A ¥ B y W x (¶P ), ÷x 0 y W A¥ B 9 I_ A ~ B A ¥ B ' ÉÊ ³´ I_ ( A I_ xAx I_ AA¥ B ' Ä B c
I_> $
{An }
' @A
I_> $ {A } ' É 0x c /0 öø÷ 01Þß 45 I_^û LQF¿À ' R 1.3.1 N A, B, C O !"# ' S FV B ¥ C ª x F01 I_ G ' (1) A AB C ~ xA− B − C I~ _ A − (B ∪ C); ª (2) A ¥ B C F01 G ' ABC ~ AB − C ~ I_ AB − ABC; '
(3) S Ä F01 G '
lim inf An n→∞ ∞ T ∞ S = An
n
k=1 n=k
c
c
c
AB C ∪ A BC ∪ A B C; '
ù F01 I _ G ' (4) S Ä c
c
c
c
c
c
æjçmè éêëì
12
ABC ∪ AB C ∪ A BC ~ (AB ∪ BC ∪ CA) − ABC; m ' ª I _ ' (5) S F01G ABC;I_ '
(6) S ÉÊ F01 G ' ∪ (ABC ∪ AB C ∪ A BC) ∪ (AB C ∪ A BC ∪ A B C); [ A 0∪ B1 ∪IC_ G ~ ' (AABC B C ) . R 1.3.2 TU 110 VWX Y '[Z VW=Á\=;FÀ=% ö ÷ 1 A I=_ VW Á\ x Ê k Á ( B I_ VWÁ\Ä]G k Á ;F\] }¡¢ ' I_ VWÁ\Ê k Á ( B I_ VWÁ\ x k Á A ( B B = Φ, i 6= j; A ⊂ A , A = S B ; ·· ; ^ Z / 45 Ω / 45 1 v 45_V ý 45¹ºÀc45_V ' `a ' A ∪ B = B ∪ A, AB = BA; b a ' (A ∪ B) ∪ C = A ∪ (B ∪ C), (AB)C = A(BC); cd a ' (A ∪ B) ∩ C = AC ∪ BC, (AB) ∪ C = (A ∪ C)(B ∪ C); ®efg (De Morgan hi ): (A ∪ B) = A B , (AB) = A ∪ B . wk k 4 5 W kl 4 5km > 'on 2 Zkpkq k j u n pq u; öø÷[ 01 rs L fU µ 45/ 2p m > ;d01 t7 á De Morgan _VuG ' ' :ßx / G ÿy ; ±vͱvw±vͱv , -JKs z{ 1.3 1. | A × B } ~ § Ò¶·" ë Å´ä
¼ £ ¶· X: (1) AX = AB; (2) (A ∪ X) ∪ (A ∪ X) = B. 2. ë Ò¶· A × B, ÅÛº (1) A ∪ B = A ; (2) AB = A . 3. Ó £¶· X, (X ∪ A) ∪ (X ∪ A ) = B, ® A, B ° 嶷 ß 4. Ò¶· A × B, Å´
¡ ä º A ⊂ B, A ⊃ B , A ∪ B = B, A ∩ B = A, A − B = Φ. 5. | A × B } ~ § Ò¶·" ë Å´¶· £ º c
c
c
c
c
c
c
c
c
c
c
c
c
c
c c
k
k
c k
i
j
k+1
k
c k
∞
k
n
n=k
c
c
c
c
c
c
c
c
c
c
c
c
c
c c
c
(1) (A ∪ B)(A ∪ B c ) ∪ (Ac ∪ B)(Ac ∪ B c );
(2) (A ∪ B)(Ac ∪ B c ) ∪ (A ∪ B c )(Ac ∪ B);
6.
7.
(3) (A ∪ B)(Ac ∪ B)(A ∪ B c )(Ac ∪ B c ).
¦ [0,1] x, A = {0 ≤ x ≤ ë¡¢£ éê Å´¶·º 붷
(1) AB c ;
(2) A + B c ;
A 1 , · · · , A5
2 }, 3
(3) (AB)c ;
éê Å´¶·º
B = { 41 < x ≤ 43 } (4) (Ac B c )c ;
×
C = { 31 ≤ x < 1},
(5) (A + B)(A + C)c .
§1.4
çD ¡¢£¥¤
13
(1) B1 = {A1 , · · · , A5
(3) B3 = {A1 , · · · , A5
ʦ¸¹ 2 § }; ½¸¹ 2 § };
(2) B2 = {A1 , · · · , A5
(4) B4 = {A1 , · · · , A5
ʧ¸¹ 2 § ¨ ©¸¹ }.
©ª«¬®¯°±²³´µ·¶¸¹º» 1000 ¼½¾¿· 811 ÀÁÂÃÄÅÆÇÈÉ ÆÒÓ Ô 356 ÀÁÂÃÄÅ·ÆÇÊÌËÎÍÆ 348 ÀÁÂÈÉÆÇÊÌËÎÍÆÏÐ 297 ÀÁÂÑ ÆÕ·Ö×ØÙÚ 9. Û A, B, C ÜÝÞßà·áâ²ãäåæç»èéêëµ (1) ABC = A; (2) A ∪ B ∪ C = A; (3) AB ⊂ C; (4) A ⊂ (BC) . 10. ìÞßã {A } íîïðà·ñòóô n ∈ N , õ A ⊂ A , ö÷èéøùúûâ S 8.
c
n
∞
lim sup An =
n
n+1
An = lim inf An .
üýþÿ» Bernoulli ö·ÏÞß A “Þß A ¶ n ö à·Þß B Ü “Þß A ¶¶ n ö¿ m (1) öÏ A B ; (2) ö Þß B = T S B ; S T T (3) B = B . öºåæç A ⊆B A ⊆ B ÿ 12. ¿ õ ÇÌË à ¿ "!"#" n $à Ï A i $¸# »oË%» Þß (1 ≤ i ≤ n), ö÷ A ±²äÞßµ (1) &õ n $'o% Ë ( (2) )*õ× $o%Ë ( (3) +õ×$oË%( (4) ,- k $oË ( (5) ,*- k $o%Ë ( (6) +õ k $o%Ë ( (7) &õ n $./ 13. 01%2À ² 3à·Þß A 0%4à·Þß B 1%4·±²äÞß"5"6 ""7"8 ê9µ (1) A4B ; (2) A 4B; (3) A 4B ; (4) B \A; 5) A \B. 14. ì A, B, C ÜÞßà·ûâµ n→∞
n
n=1
11.
n
n,m
i
4,2
∞
m
n=m
k=0
m
∞
n,k
∞
m
n
m=1
∞
c
n=1
c n
n=1
i
i
c
c
c
c
c
c
(1) P (AB) + P (AC) + P (BC) ≥ P (A) + P (B) + P (C) − 1 ;
(2) P (AB) + P (AC) − P (BC) ≤ P (A).
ûâµ·±Õ A4B = C4D, : A4C = B4D. ûâµ·òóôÞß A, B, C, õ P (A4B) ≤ P (A4C) + P (C4B). 17. ûâµ P (A4B) = P (A) + P (B) − 2P (AB). 18. ûâµ P (A ∪ B) = P (A) + P (B) − P (AB). 15.
16.
; <=>=?=@=A = BDCDEDFDGDHDEDIDJDKDLDMDNDODPQDRDSDTDUDVDWDXDYDZDEDFD[D\D]D^D_D` §1.4
a bDcDdDeDfDgDhDiDjDkDlDmDn D oDp ^DqDPrEDFDsDtvuwYDxDyD\D]DODzD{rWDyD| ” MD} ”, WDyD| ” D ~ ”. TDDDDD
D_DDDD}DDDvuw[DDxDyDODzD`DDWDyDDtD` 1.4.1 DwDDDDDDDDDDD Px WGD¡¢D£G [ D ¤ P YD¥D¦D§D¨D©D[D¢DG ¤ «ª §1.4.1
};
¬ w® ¯D°D±D² v ³µ´ Y µ¶
µ£µµyµsµtµ|µ·D¸µ[D}µDsµtD{%¹ µ u»ºD¼µx ¢D£µWDGµP½ QD[Dx ¢D£DWDGD¾ ³ `¿HD|DÀ IDÁD{¿Y C = 6 § ¤ D`¿ÂDÃDÄD|DÅDDÆDÇ«ª DÈ |DÄDÉD¡DTDDWDDÊÌËͨDÎDD¼DPWDÏDÐDYDDQ 3 §D¢DG ¤ D{ P } { P }; (2) { P } { P }; (3) { P } { P }. (1) { DyDÃDÄDÑvÒwPÓ}DDDDÔD¨DÕDÖDHDDyDsDtD`ÓY ³D´ ¶ sD{ÓD|D£µ×DØDÇ«ªÓ} DP}DDP¨DSD|DÖDTDÙDÚDMD}DD¢DDsDtD[DÛ«ª ÑD{ÜwÝD¨DÞDP}DD|DÖDT ÙDÚ “MD} ” “¢D ” sDtD[DPwÂD|DDßDàDÝDYDáDWDy ~D sDtD`DÜwÝDPwâDãD} DDDMD¼D[D}väwPÓåDzDæDçD|DèDY ~D [DPÓÂD|DéDODêD¼D[µ|D{ÓâD}Dëµ}DæDçDì í âDá ~D PîDïvðwñ “òDó ”! ôDõDöD÷ PâDãD}DDDDEIøDP EDI[| þ Q ¼DxDy ” [DúDYD¨D© ùDû F«üÓ`wýD Dþ ù ¼D[Dx ID£DWD}DPwÿ “ù [DxDy ID £ DWD}D ` D Ø wH “ù ¼ P P Q P ” “ù ¼ P P Q P ” |DxD§D¨D©D[ ù ¼ ¤ DPÓ¹DÿDâDD§DEDI ¤Dû uwPÓ S D I D|µxD§D¨D© DPHD|DSD Á DDQ 6 §DMD} ¤ D{ [ “MD} ” ¤ WD}D£D{ { P }; }D£D{ { P }; (1) WD}D£D{ { P }; }D£D{ { P }; (2) WD}D£D{ { P }; }D£D{ { P }; (3) WD}D£D{ { P }; }D£D{ { P }; (4) WD}D£D{ { P }; }D£D{ { P }; (5) WD}D£D{ { P }; }D£D{ { P }. (6) þ ú M¼[ } ò ó { ù ¼ [x y £ W S|ÑPâ§EI u P }DP½DQD[Dx £ }D[D`D S { P eDfDiDjD “eDf ” “D k DeDiDj ”, " jDh #%$ P &'()*+ eDk ,- " jDh #wg ./0 ` g !Dk De DSD|DÑDP éDOD N 1D
D_D}DDDD`Ó â 2DÖD}DDDDEµFDøD4P 35DøDø ö E 6 7D 7DMDâDWµyD}D[D¨µ© ¤ DPÓ ÿ 8 ÷ {ÓâDEDID¼D[DMD} ¤ DF«üwuwPÓ¨DÂD È 9 ÝD¡DE 6 :DyD}DæDçD[D¨D© òDóD¤ D` 2DÖ ;DVD
D_DP ³ < ¤= ¡DÙDÚDDQDsDtD{ 1.4.2 >? 6 y MD£ 3 }D P @D} 2 P M AD¹Dà 3 B ¨D © C D P DD M E ¤ DFD` F { ù ¼x ¹Ã 1 B CG PY C § ¤ G HI ù ¼x ¹Ã 2 B C DPY C § ¤ H½DQD[Dx ¹Dà 3 B C D`ú < WDÏDYD{ C ·C = = = 90 §D M E ¤ D` 14
2 4
2 6
2 4
2 6
2 4
6! 4! 4!·2! 2!·2!
6! 2!·2!·2!
% JKLMN 15 âDDßDP 3 B C D|D¨D©D[DPâO æDç 9 ÝD¡ í â á “D ~ ”, îDïvð ” ò M }GQRDM£ ó ”, ú < ÕDÖDHD}DDDD`PwHDMD¼D[D}DFD¥DHDxD}DP ú < ? D ST D ` §1.4
§1.4.2
DD
UDeDeDf
£ DÕ ô D§DMD£D¥Dy
“
¨D©D[
”
}D[DsDtDéDDP V ¢D¼DDQD[
“
¥D}D}
DeDeDfDiDj { Y n yD¨D©DåDzDP»O þ O MD£ k yD¨D©D[D}DPXWDÁ:D}Y U Z Y n , n , · · · , n yDåDzDP[vu n + n + · · · + n = n, \ WDÏDY ”:
1
2
k
1
2
k
n! n1 ! · n2 ! · · · · · n k !
(1.4.1)
]Dþ D §D¨D©DM û ` ¥ }D}DDD^D£ “Y D ò ó MD}DD ”. ÃDÄ;DP_DÖ` Z ù D ¼ [a ûbc P¾ ³ Á DDyDsDtD[deD{ n
n2 k−1 Cnn1 Cn−n · · · Cn−n = 1 1 −n2 −···−nk−2
n! . n1 ! · n2 ! · · · n k !
¥ }}|W§Gf õGgGh [EFPOGiGjG op úGkGl[} DDD` ÃD Ä ;DP õ k = 2 øD[D¥D}D}DDP»SD|mnD[D}DDDD`»ÿ “¹ n yD¨D©DåDz uwºD¼ k yDTD[DD ” sDtDP \ ³o £ ? n yD¨©DåDzDMD£ k + 1 ¨©D[D}DPW } :DY 1 yDåDzDP ÿ qr 1 yD}DY n − k yDåDzDPHD | w¥D}D}DDD Áp k yD ^DPÏDYD{ n! 1!·1!···1!·(n−k)!
=
n! (n−k)!
§DM û P ¾DD ¤ D`âDDßDP k yDåDzDæDçD[ ~Ds £D}DëD}DæDçD[ ~D ` Ttu ,vwxDyþ zDkDcDd sDtD` âD 1.2.5 [DÙ û 2 uþ { | ÖQD] §DEDFDDD` â DßDP Ð}%~DD©DWD§DåDz (¨ ³ M ), 3 Ð~ 7 D©DWD§DåDzD` HD|O ú ´ D[DúDYD¨D©DDF«üÓSD| þ 10 y
DM :DY 7 yD 3 y
D[DMD} ¤ DF«üÓ`PwHDMD[DxDyD}| “Y AD[ ”, ú < Õ ÖDHD}DDDD`" W D¡DP õ MD¼D[D}D£ k yDP k ≥ 2 øDP õ ÝDS ³< ÖD¥D}D}DD TÙÚ`ú < PG ¨ fGåz[G [ÄS| ? úY¨©G [ G
G M k y¨© [D}DP DÆDSD|DGD¥D}D}DDDD[DWD§ ô ÖD`r£ = H r ô ÖDP ? [ V ¢D£D{ P DH k yD¨D©D [ DP © DåDzDæDçD¨ , v w x y DkDcDdDiDj Y n yDåDzD z ³
D P :DåDzD M ADY n , n , · · · , n yD P [vu n + n + · · · + n = n, O þ O DWDDP \ WDÏDY 1
2
k
n! n1 ! · n2 ! · · · n k !
1
2
k
(1.4.2)
16
¬vw®
¯D°D±D²
<
Ñ¥}}
§D¨D©D û ` ; VÃÄÑ Ò ¥}}âEFst u [\GP¡G`ú DD| ú D[DWD§qD\D]D[DEDFDDD`
JKGu u [G¥EFstP ³G
n , n , ···, n n + n + · · · + n = n. §D¨D©DM û ª ¨DÎDD¼DPDyDsDtDSD|DWDyD¥D}D}DsDt{O þ n yD¨D©DåDzDMD£ k yD¨ ©D[D}D% P WD Á :D } Y Z Y n , n , · · · , n yDåDzD% P [vu n + n + · · · + n = n. ú < w¥D}D}DDD §D^DqDPWDÏDY 1
2
k
1
§D¨D©DM û ` µßµYµxµy¨©µ{«ª
2
1
k
2
k
1
2
k
n! n1 ! · n2 ! · · · n k !
, µk P ¬,G-µk P¯®DÕDÖµHD¥µ}D}µDµD` £° ¤ {rY n yfD©D[¥ PO þ O M6 k yD¨©D[ ¢D` WDÏDYD¥D¦D§D¨D©DM û ª âDDßDP n y |D f ©D[DP k y D¢ |D± ¨Df ©D[D`D Æ ÐDéDODZ²: y ¢vuw[ FDPÓÿD ³ é bc´ y µ â ´ y v¢ uw`ÓâDDyµsDtvu»P èDYDê ¶ :Dy ¢vuwúD· [ FDP4D £DW¸ F¹ ¶ P \ M D¤ ] S¹ ¶ D PÓú < SDÐ Y 1 §DM û D
` ³ þ sDtºD» £D{ yD f ©D[¥ % WD¼ D½ P»ÐD5 âO æDç¾; k − 1 ¿ÀÁ P þ O À n £ k  PÝrÃ:  G ó ·6f ô [ ¢D¾ ³ ` GDDyDsDtD[DÙD d éDMDxD§ÄÅ bc { { ƵøµG ÀÁ [·
µ
èµYÊµË PÍf õ HµO ? n+k −1 (1) ÆÇÈ!É yD¨fD[DåDz D DDPÌ[vu 1 DåDz (¥ ) Y n yDPÌ 1 DåDz (ÀÁ ) Y yDPú < w ¨fD åDzD[DDDDD^DPWDÏDY k−1 §D¨D©DM û `
k−1 n Cn+k−1 = Cn+k−1
{ÓÆDøDG ÀÁ [ ·
DYÊËDPD£DÐ ´ þ ÀÁ ·
, Æ Ç È ! É â n y¥ ú D[ n − 1 yDç À ;DP Ô8@DyDç ÀÍ ¥ ³< ·
DW ¿ÀÁ P ú < ÐDOD¹ n − 1 yDç À u ù ¼ k − 1 yDT·O ¾ ³ `®DY C §D¨D©DM û ` (2)
k−1 n−1
% JKLMN 17 DyDsDtD[¨ÎD|D{ w- P ¬,w- ` DQD[DDtD| DM 6 DDD[DWDy ô ÖD` 1.4.3 ºY ¤ R x + y + z = 15, Ï MGAGD¼GO[BGÐFÙÑÒPÐF Ù [D}DFD` (x, y, z) F 4{ º»D£ ? 15 y ³ AD[ ¥ M 6 3 yD¨D©D[ ¢DP IDM A ? 1, 2, 3 y vuw[ FDG ô £ x, y, z [ ÓD¾ ³ `»ú < XP ÑÒÐDFDÙD[D}DF (f õ H ÔD¼ ÕÖ D[ ÄÅ ) £D{ §1.4
ÿDBÐDFDÙD[D}DF
f (
õ HD¨ÔD¼ÕÖ D[ÄÅ ) £D{ 15 2 C15+3−1 = C17 =
£× ¤ {rY WDÁDY k y ¢:DY n y¥ ¢:DY n y¥ P[vu
3−1 2 C15−1 = C14 =
1
1
17×16 2
= 136;
yD¨©D[¥ PO þ n PY k y ¢:DY 14·13 2
O M6 k y fD©D[ ¢DP y¥ P · · · , Y k y n
= 91.
2
2
m
m
k1 + k2 + · · · + km = k,
k1 n1 + k2 n2 + · · · + km nm = n.
WDÏDYD¥D¦D§D¨D©DM û ª DyDsDtD[¨ÎD|D{ ,- P ¬w- `ØDÆDÐDéDOZ²Y S yG ¢G· S y O Ù “´ X ” ¢· “´ S y ” P»ú < ^D£ “³ òDó MD}DD ”, ÷ ¾ P»ÿD¨DéD GDMD¼D[D}D¨D Ö ¾ < MD`DyDsDtD[DÙdÚ%ÛÜÝDP È |DD¹DWDXD¢DÞD` pRGU Q[ [stS| “³ òó M}st ” [ qµ·µ¸µ[µ ¢µß` »HµÖµ}µDµDIµ¼D[µMD} ¤ µ| àµY òµó [DP % GDúµMD¼µ[D} ~D `"xDyD}D[ ~D Y 2! §DP"ú < ÐDO ? “Y òDó MD} ¤ DF«ü ” á < 2!, ¾ Á “³ òDó MD} ¤ DF ”, DÆDYD{
³ “
M } ” ¤ D`DyD¢âDBãDëäåD[DMD} ¤ DF«ü4fæD` òDó D IDTDDWDyD¢D` 1.4.4 O þ 7 MD£ 3 y¥D}DPç ©DWD§èéDP[vuwWDyD} 3 PDx yD}: 2 P DDMD} ¤ DFD` F ë{ êDÝD ] |DWDy “³ òDó ì } ” sDtD`»ÂD|DìDë ;íD[ ÄÅDYDúD¨D©D`X £[vuwYDWDy 3 } uD|DÅ òDó î¦OD ë [ïDxDyD}DYDú A (òDó ³ÑD|D£
ð ì ¼D[D} ¾ < ì ), ú < âDã “Y òDóì }DD ” ñ ¼ ì } ¤ òDæ rî Ð ô I á < 2! (¾ áóôõö ¾ ì÷ø÷ùúûü ò ), ®ýþÿ §
C42 2!
=
4! 2!·2!·2!
=3
· = ìø mQ;tuî ý ì ÷ þ “ ìø 7! 3!·2!·2!
1 2!
7! 3!·(2!)3
”
ò α “!"#$ì÷ùú ò ”β, % ý&' ÷ ” ! ìø ” òî () þ 18
n! , k k (n1 2 !) 2 · · · (nm !) m β = k1 !k2 ! · · · km !. α=
(1.4.3)
!)k1 (n
(1.4.4)
+*+,+-+.+/ )î0F+G ( ö#+132546+78+9÷+: ;+< ÷+=>+?@+A, øBC÷ ADE 12 HJIJKJLJMJNJOGþP n õGöJQG÷JRJ îTSJUJVJ ìJ k õJWJQG÷JXJY îTZGý îT k õXY[ n õR î · · · , k õXY[ k õXY[ n õR î () n õR n + · · · + k n = n, \] ÿ k ö+Qkì+^ · ·î · +(k) α= _ k, β kìn`8+ k(1.4.3) _ (1.4.4) &a Mg §1.4.4 bcdefbc h ùúø+B + ) î0i+ ]+j ?+k+l Z+m+no+p ùúø+B÷ î ì+`q ? k ùú_?k øBT?k ùúrst þ O þP n öJQ mJG n îTS @ )vu 7 k õJw oJp ùGú î Q mJn ? bZJ cJîdJ\e ] NJÿG öQ÷ (kl ) ùú kl n xyz îT{ õ|} z &~ } ÷ mn n öQ u î ] ÿ u k î ý C buc TMSg'
&÷^ þ u n öòQ mnS @ )u 7 k õw Q mn ? kl 7 öQ ÷ +< ÷+ õ ++ + j X+ ÷+ x+yz & u 7 ÷ k õ mn n öQ j W, U k õWQ÷R ~ n õöQ÷XY ?7X & þ g+N+O þ n öQ m+n+S @ )5u 7 k õ+w Q m+n ?+k+l+ u + b + c \ 1
1
2
2
m
m
1
2
m
1 1
2 2
m m
α β
k
öQ÷ u g §1.4.5 ¡ ¢£¤¥ G |}öW¦÷øB § 8 h § ª« öW¦ ÷¬ õ ÷ ]®¯ ^ þ k−1 n Cn+k−1 = Cn+k−1
1.2.3
) S'¨© ô|
§1.4
°±²³´ S @µ¶ {1, 2, · · · , n} )u 7
k
õöQ÷µ
1 ≤ j1 < j2 < · · · < jk ≤ n,
(1.4.5)
j2 − j1 > m, j3 − j2 > m, · · · , jk − jk−1 > m,
(1.4.6)
Z·¸¹º»þ ()
19
¼½µ (k − 1)m < n. S' 7 & öQ÷ u ^µ ¾ ' 7 (u ^µ T¿UV QÀÁ÷øB ]ÃÄ r 8JÅ S J @JµJ] ¶ {1, 2, · · · , n}) ¨J Æ u 7 T&k õGu öJQG÷Jµ 1 ≤ j ¸<¹j º<»·þ · · < ≤ n, ÇÈ õÀÁ÷øB öÉ 7÷ k õµÊË m
1
jk
2
j2 − j1 > 0, j3 − j2 > 0, · · · , jk − jk−1 > 0.
ÌTÍÎ ÷ u ^µ C . JJÏJÐJJ J Ê SJ& u 7G÷ k õJµ ¸J¹JºJ» (1.4.5) _ Á £ ÷øBѵÒwÑÓ (u ^µ T h Ô i = j − (l − 1)m, l = 2, 3, · · · , k, ÇÈÕÖ
(1.4.7)
k n
l
i
(1.4.7),
ÇJÈ ?J
l
1 ≤ i1 < i2 < · · · < ik ≤ n − (k − 1)m,
−i ) ¨>Æ 0.u 7÷ k õöQ÷ × Í i , i , · · · , i i −i @>µ0,¶ i{1,−2,i · >· · ,0,n −· (k· · ,− i1)m} µ+) Ù¨Ø Æ ·+u 8+Å 1 ≤ i < i < · · · < i ≤ n−(kS−1)m +@+µ+¶ {1, 2, · · · , n−(k −1)m} Ô 7 ÷ k õöQ÷µ ÇÈ Ê ÚÛ (1.4.5) _ (1.4.6)j =ÜiÝ + (lz −1)m, Þ ßl à= á 2, 3, ·Ø · ·ß, k,à ]]â ÷ × ÍÞ õ u µ ÷ u ^µ Wãåä Í ý 7 þ gNO þ 8Å S @µ¶ {1, 2, · · · , n} )u 7 k õöQ÷µ æZ·¸¹ ¡ º» (1.4.5) _ (1.4.6), ÇÈ & öQ÷ u ^µ þ 1
2
2
1
3
1
2
2
k
k−1
k
l
k
l
k Cn−(k−1)m .
< T ? U bc gèç Ü 0 ¡ g , % U ÷ Jé (1.4.8) ÑJÓ ( øJBJµ êýJ J C ç Ü −1, J ÷?køB ( Cë ìí 67î ÅWQ h T wï89 þ
k n−(k−1)m
(1.4.8)
(1.4.7)
) ÷ m öJQ
k = Cn+k−1
ð 1.4.5 10 ñ 4 ªòó 4ôÜ ] põ'{Þ | ª« ·ö÷øöùÞ |ñ « î¬ ú þûü ö Ω ýÖä 14 þôÜ ] p î &ÿ Q^Ü |Ω| = 14!. B a¨©Þ | ª« ·ö÷øöùÞ |ñ « î x » \ x » B ä ] 8 Å ¸¹S' î^Ü T w ç 8 © ÑÓ |B|. ¿ â 14 |} op % S @ 14 |} ) 7 4 |}6 ª« åä ©Þ | ª« ·öJ÷øJöJùÞ |Jñ « T& , n = 14, k = 4, m = 2 î ,ö¨ |}
B ä (1.4.8) C =C ñ « _ ª« h & ý î|} z % ý 20
k n−(k−1)m
&
4 8
|B| = C84 · 10! · 4!, C84 ·10!·4! 14!
C84 4 C14
70 1001 .
z ï i +¾ ü+ î ] º þ Ω a+&++ÿ Q+î+|+} \ ý |Ω| = C , +, x » B ä ] B +S ' +î |+} ++Ü % |B| = C , , P (B) =
=
=
4 14
4 8
P (B) =
1.
C84 4 C14
=
70 1001 .
1.4
(1) Cn1 + 2Cn2 + 3Cn3 + · · · + nCnn = n2n−1 ;
(2) Cn1 − 2Cn2 + 3Cn3 − · · · + (−1)n−1 nCnn = 0;
P
a−r
(3) (4)
a−r Cak+r Cbk = Ca+b ; k=0 2 2 Cn0 + Cn1 + · · · +
n (Cnn )2 = C2n .
! "#%$'&()* 6 +,-/.01+,24345* 0, 1, 2, · · · , 9 6789:,2-/;4<4/= "5>?@A: 6 +,23BCD#E$'&4(4)EF 3. 5 GHBIDH#HJHKHLHMHNHOHPHQHGHBIDI#R$TSIOHIUH9IVH-XWHYI7H8IZH[R$/SHOIBI\^]H9 _`ba ?@AGc4d4eEF ` 4. f r :B5gh#%i'jP r :B5gh#kjlm n :n6-o;p5qg#leG, _ w 5. f r :Dr#stP r :Dr#uv9 94x4-b;4<4?4@4A54y4q4g4#z4YEF 6. { r :B45gh#%i'j4- r :B45gh#kj4- r :B45gh#|j4}4~4V44-b;4< ?@A65yqg4#V44d4EF ` ;4p4 (1) n 7. { n :BD#j7l4m n :BD#n-b1jm44n34*4454> ` (2) 1 (n#
` ;p4W4444 8. { r :CD#jlm44(4* 1 n # n :n-b1jmn434*4454> #
A = { 0# r :n69j }; B = { 1n@ 1 j }; C = { 0#n6 ? m :j }.
2.
1
1
1
2
2
1
3
° 21 ` ;4p4W444 9. { 3 :4B4D4#4j4l4m44(4* 1,2,3,4 #4Q4:4n464-b14j4m44n434*4454> #
(1) ?Z:n (2) ?jn#(* 2. 10. .404748494:44#4E]47494:444H4
4H#4-b;Hp4H44H4#4
H4 (1) 12 :4 #%'] 12 :BD# (2) 6 :#%' ]Z4:46 ` 11. (¡ ) ¢0 30 :-b;p 12 :6? 6 : £¤Z4:4#4E-X? 6 : £ ¤ 3 :#%'#
` `®4¯ B4°±4²49f4>4ª«4¬- ¯4³ O´4µ¶ 12. 9:? n f¥¦-¨§©?9f>4ª«4¬ · ¥¦¸;« `X¹4º -b1494f4¥4¦4]41494x4;4»464¼H½64#4
444 n . ¾¿¤?Dr @#;»x,#ÀÁ5>zY44` CÂ#4-o¶4:4 4]à r xf¬ª«#
`È@¹A%º F 13. !Ä? 4 :ÅÆ-ÈÇɸÊËÌ ]ªÍ4# 4 :ËÌ6? 3 :ÅƪÍ# ÄÎÇÏ ` ÇÐ?4Ñ 4ÒÓ ¶4Ô4À4Õ4 %F;4`ëÖê × º <Ø4Ù ³ O4l4jm4n4ÚÛ4#4ÜÝ ` 14. !Þßà]!9áâã-åä4æç4èé4< 12 x ?¶ 12 x#é< ]áâìPá â4Q ` ;4p4=444#4
4 ` 4Ð454y4í4î ¯ ¯4©4ò4]4óá4â4ì4P4á4â4QHç4ï4é4<4ðRF¶ 12 x4é <ñö ?9x]áâE-b4Ð454yí404á4âE B4ôõEF 15. · ()?4þ(4ÿ) 1,2,4· ·x · ,NV4#44j4#464
4#4 ÷4` t464?4lEø´4ù4ú n x4j4-bû4x4ü44ý4(4)4-b;4p4¶ 16. ] Ø6¶ · ()4þ (B90ÿ ) #x V#
` 17. 7 , 1, 2, · · · , N 6Bl%ø'´ n :, - þ V* x < · · · < x < · · · < x , ;p x = M #
(1 ≤ M ≤ N ). ³ O´ U9V 9 4-;4g 4p Z4G 44-]4Z:440#4 4 ? s : 18. n : #
` 19. n :4 4U49 44-bý464? A P B ì44-b<44? r :4 4] A P B 4#4
44* 8%F'WY ¯ ÉB 4U944¾4 U49 ` ;44¶4:4
4Ù ` r -b¾¿ 1/n. 20. * A !#"x4,4-b{ 2n :j #g*Z $` -b1 $ n : # ;pW4#
44XZ: %# j #¼g] (1) BD $ (2) D9 $
§1.5
−1
1
n
m
m
& '()(*(+(,(-(.(/ ( 0 ¾ o ]21 ¾232425¬ 627 w ç ]28 § Y29 ¬++C@ ) î;:;<;=;> ?;? “X )5u;@ 82” ]2î;^ A;B;C;D;EGF;HJILK;M;N 8;O û@ 2 Pî2P (Q2R2S2T2U2M2V2W ), XYI[Z2\2N Z2_2M2`2a2E[N2a2b2Z2\2c d KYe ^gf2h Z2i2N2j ^gk20 “l2KYe[m2Z ” n “l2KYe[m2o ”; p2N2a2b2q2Z2\2N j @2r KYe ^s Z2i2N2j @ ^k20 “M2KYe[m2Z ” n “M2KYe[m2o ”. t 1.5.1 F2HYI[K2M 10 j2u2v2U2M2V2W 1, 2, · · · , 10 c2P @ ^ XYI[w2x2m2Z 3 j @2yz u2v2{ “l2KYe[m2Z ” | “M2KYe[m2Z ” }2~22E (1) 3 j22c2V2W2 d 2 7 c22
2 (2) 2Q2c2 V2W2 7 c22
y E A 2 3 j22c2V2W2 d 2 7 c222 B 222Q2c2 V2W2 s C 2 3 j22c2V2W2 d 2 6 c22 y 7 c222 §1.5
Y[ 222 “l2KYe[m2Z ” }2~2i ^ Ω “X 10 j d O22 I[2Z 3 j d O22 ” c M d O ;_;; ^¡ M |Ω| = C . ; A “X 1 ¢ 7 V;;£ 7 j d O;; IL Z 3 j d O22 ” c M d O 2_22 ^ M |A| = C . ¤ 2 B I2 7 V 2N2¥2¦2Z2\ ^ 2§2¨ s X 1 ¢ 6 V22£ 6 j d O22 I[2Z 2 j d O222^ M |B| = C . 2©2ª 22
3 10
3 7
2 6
C73 3 C10
P (A) =
=
7 24
,
P (B) =
C62 3 C10
1 8
=
.
“; M KJeLm;Z ” ; } ~;i ^ ; S « Ω ¬; “ 10 j d O;; IL;Z 3 j ; c;S 2®2¯ ” c M d O ® 2 _ 2 ^° M |Ω| = 10 . { 2 A, ±2²2³2´2M |A| = 7 . 3
P (A) =
¶µ¶·¶¸ |A| − |C| = 7
3
¹¶º¶¢ − 6 , X2¤ |B|, 3
»¶¼
B = A − C,
P (B) =
73 −63 103
=
7 3 10
7 3 10
3
.
½¶¾
C ⊂ A,
−
6 3 10
=
|C| = 63 ,
|B| =
127 1000 .
Q2D2¿2À2Á2ÂYI Ä ^ Ã2Å2Æ2Ç µ2È2É2c2Ê2¸ yÄË2Ì ¹2º2¢ P (C) = , Í2Î Ã2Å2Ï2Ð2Ñ2Ò £2o2N2j Ò2Ó E Ô B = A − C, »2¼ C ⊂ A ª ^ M P (B) = P (A) − P (C). r 2 Ã Å 2 Ð 2 Õ 2 Ö ^ 2 Ò 2 Ó × b22
2c2Ø2Ù2Ú2Û “S2Ü2Ú ” c2Ý Ò y « £2N Ë2Ì d¶Þ2ß Q2à2}2_2·2¸ |B|, Í2Î2Ô2á2â2S222\2ã2ä ^å b¶¨2æ¶ç2è¶é y u¶v¶ B , B | B ¶ 7 V¶¶¦êZ¶®2\ ¯21í ë ^ 2 ë¶| 3 ë¶c¶¶ ^ ±¶ì ®2|B|¯2í = ^ |B | â2î2ï Þ Þ |B | + |B | + |B |. |Ω| = 10 b 2 ~ 2 · 2 ¸ c ~2·2¸ y |B | c2·2¸Yð[ñ2ò2ó ^ q2ë22§2T2Z 7 V2 ^ |B | = 1 = 1. ·2¸ |B | ª2î2ï2ô2õ 7 V22b 2ö2÷ ë2Z22ª2¦2Z2¢2c yÄø © |B | = 3 · 6 = 108. O2ù2^ |B | = 3 · 6 = 18. X2¤2ì 1
1
2
2
6 3 10
3
3
3
j
3
3
1
1
3
2
2
P (B) =
|B| |Ω|
=
|B1 |+|B2 |+|B3 | |Ω|
=
108+18+1 1000
=
127 1000 .
t 1.5.2 úLû;ü;ì r j;ý; ^ b j;þ; ^ XJÿ;º;Z;\ n j; ^ r + b ≥ n. z ;u;v;{y “lJeLm;Z ” | “ìJeLm;Z ” `;a;};~ ^ ;ãJÿ;ì k j;ý; (k ≤ r) c22
Ç A 22ãYÿ2ì k j2ý22c22 y ¬ Ω 2X r + b j22Z2\ n j2 ] ÷ S2T2Z2_2c2È2É y c “ l Ye[m2Z ” ª ^ ì |Ω| = C . Ô22 A Ñ ª ^ø X r j2ý2Yÿ[Z2\2µ ^ X b j2þ2Yÿ[Z2\2µ n − k j ^ |A| = C C , © kj n r+b
k r
P (A) =
ìYe[m2Z ^ b2ãY ÿ 2ì “
Crk Cbn−k . n Cr+b
n−k b
Þ S 2®2¯2í ~2·2¸2\2c
ª ^ ì |Ω| = (r + b) , ¹2º2£2b ø © ·2¸ |A| ª ^ â2î2ï2ô2õ “ ”. Ô22 A “ ”.
”
n
2 23 Ñ ª ^ X r j2ý2Yÿ[ìYe[´2Z2\2µ k j ^ ì2Z2_ r a ^ X b j2þ2Yÿ[ìYe ´;Z;\;µ n − k j ^ ì;Z;_ b a ^ å b n ë;Z;Jÿ ^ ö k ë;; Z \;ý; ^ ö n − k ë2Z2\2þ22ì ÷ j d ²! 2 c ®2¯"#2y |A| = C r b , b2¾ §1.5
k
n−k
k n−k
b k P (A) = Cnk r(r+b) n = Cn
r r+b
k
b r+b
n−k
k k n−k n
.
%$ ¶ à ¿¶À ÿ öŠ趢¶c¶`¶j%& Ì ¶ì ¨¶c¶¶
¶º%' ^ (¶Å u¶v¶{¶³¶µ ¶
%) ÿ°c%*%+%,¶u%- (l% e/.êÉ ) |%0%1¶u%- (ì% e/.êÉ ), öŠ« ж%2 r 32÷456 y t 1.5.3 « n j d7 c829 m j d7 c:; ^ n ≤ m, <2j29<2j :;;c;x Ð ² = y!z Ë i<;2;c2;
(1) > ¥;c? n j:Jÿ<9 1 j 2 (2) q2 j :;2 @2 é 9 1 j22 (3) > ¥2c? 1 j:Yÿ9 k j2 y u2v2 A, B, C 2 3 j22 y Þ S 2®2¯2í ~2·2¸ ^ è |Ω| = m . ^ ^ ® 2 A ÿ ^ n j d 7 > ¥2 c 2 8 2 ¦ 9 c ? n j Y : ÿ q : 1 ¯2í ~2¾ |A| = n!. 2 B ÿ ^ ì n :Y ^ ö n ÿ < 9 1 j2 j :; ì C a 2 ® ¯ ® ^ s 3 B ^ ^ 2_ {82 £A:Yÿ ì n! a _ è |B| = C n!. 2 C > ¥;c 1 ÿ ^ j :J ÿ ;ì k j; ^ ö k j;C ì C a;;_ ^ ¤; ã D n − k j; ^ ^ j :JÿL S ;ºE ì ;_ (m − 1) a è |C| = C (m − 1) . F ãÉ D$ à m^ −è 1 n
n m
n m
k n
n−k
P (A) =
n! mn ,
P (B) =
n Cm n! mn ,
k n
n−k
P (C) = Cnk (m−1) mn
.
n−k
Ò J%(¶Å c 2n j%K%L¶`¶`%¶º%M f yz Ë i%<¶ t 1.5.4 ì n G%H%I ^% 2c22
(1) n GHI&2 n jN2 (2) n GHI&2 1 jN y u2v2 A | B 2 $ à022 y Ω ³2ÔY ÷OP cM f }2~22 y ÃêR Å Qê] ôêõ |Ω| cêê_ y O R SRT J 2n jRKRL ® ÷RBê^ á rRU ¥ê«RV 2k − 1 j KLWV 2k j KL2 ² M f2^ k = 1, 2, · · · , n, b2q ÷ a ® _2{2³ ÷ aM _ ^ è Ω = (2n)!. 2 A ÿ ^ qGHI2c2`KX B M f2^ £2²2Ô 2n jKL2c ®2¯ ÿ ^ q ^ b O%Q { n GHI 3B ®2¯ ^ Q ¶ Z ¥ % < % G H ¶ I c G H 2 I 2 c ` 2 K 2 ² Y % E r[ E ^s ô2õ2 q GHI2c2 ` K2 c \ r[ E ^ è2¾ |A| = n!(2!) . ; B ÿ ^ {;q;j k (k = 1, 2, · · · , n), V 2k − 1 j [ E $ WV 2k j [ E $ E; d ] 7 ÷ GHI ^ ; c KL;[ ³ 8^_; y Ã2Å;] {;q2j k ` ÷ ô;õ y V 1, 2 `;j E $;^ d P 7 ÷ GHI2c;`K ^ <;ì 2n | 2n − 2 a;;_ ( V $ 2 j [ E $ d ^P Ã;Å V 1 j [ E $ HI2c2p ÷ [ K ).$ 2µ2 ô a V 3, 4 `2j [ E c ; _ y S T b ; c « V 1, 2 `;j E [ c KLM f;^ b de2i Ï ^ n − 1 GHI £;ª [ JeL¢fg;chi ¾j2k;c2`;j E<2ì 2n − 2 | [ 2n − 4 a22_ ( V 3 j E $2^ O 2º_ 2n − 2 j KLYÿ[ l 1 j2 V 4 j E $ n
Y[
24
^ O ¾V d P [ V 3$ j [ E $ HI2c2p ÷ K ); m2©2iyn 2k j E 2 < ì 2n − 2(k − 1) | 2n − 2k a22_ ì 2 F É $ à ^ è P (A) =
n!2n (2n)!
=
1 (2n−1)!! ,
P (B) =
(2n)!!(2n−2)!! (2n)!
2k − 1
222
j [ E $ WV
|B| = (2n)!!(2n − 2)!!. =
(2n−2)!! (2n−1)!! .
Ò22Ã2Å2]o \ "# (1) cqprs t . u Ç “lvw;u; í ~ ”. « 2n jKL;u; n j;lvw;c; ^ ; ^ q ; ; ` j K L 7 ÷ x[c2`2 j KLM f y y ì d7 c2u22}2~ |Ω| = = = (2n − 1)!!. y Ñ ^ a ; A ª qGHI;c;`;jKL;;u 7 ÷ ^ §;ì ÷ a;; u _ ^z |A| = 1, = . P (A) = ÷ | y { á2`2a2¿2_2c& Ì t 1.5.5 ·2¸2x2ü}2ì2}2Â x + x + · · · + x = m c ì~ 2¿ ^ ãYÿ × ^ n ≤ m. _Yÿ[w2x2 mb ´ l ÷ 2¿ (x , x , · · · , x ), z 22¿2b ×
2¿2c22
y $ à2}2Â2c A 2 $ à22 y ± |Ω| | |A| u2 v = ì ~ 2¿2c y í × 2 Æ Ç ^ j 2| 2¿2c2 j
V 0 2u2 9:2c ~ ST2« m j2² 7 c 822u r ^ ^ d 7 92j ÷ n cÏ :; á «V k ÷ j:;Yy ÿ[c2 ^ 2 x c2÷ ä k = 1, 2,Ë · · · , n. { á;q a ;_ {;³; µ
;};Â2 c ;¿
2};y Â2c;q 2¿;â2; ©2}2~ y ÷ {2³2µ a2u2 9:2c2}2~ 2 ` 2c2 j 2 ² = 2 Ò ^ × |Ω| = C ; ;¿; ~ ;
; ¿ c h ; i ; { ³ ì 2 : \ c h 2 Ò ^ d i2{2³ ì :2\ |A| = C . b2¾2ì (2n)! n!(2!)n
(2n)! n!(2)n
1
|A| |Ω|
1 (2n−1)!!
2
n
1
2
n
k
n−1 m+n−1
P (A) =
n−1 m−1 n−1 Cm−1
.
d7 c ^J(2Å w2x2´2u o 5 j y z Ë i<222c2 1.5.6 ì 10 Ù
(1) ^%[^/ <2è 2y Ù ^/ è 3 Ù ^/ è 1 Ù2 (2) ì 3 2è 2 Ù ^ ì 1 < 2è 3 Ù ^ ì 1 2è 1 Ù u2v Ç A | B 2 $ à2`2j22 ^J Ω ¬2Y ÷ “u2 }2~ ” 22c y 2 2 ® 2 ¯ í í O È2É ~2¾ |Ω| = 5 . ¤Y[é222É ~2¾ |A| = . t
n−1 Cm+n−1
10
10! (2!)3 ·3!·1!
P (A) =
i ] Ù ^ ì 1 2
QJ
^ 2 1Ù ì u2_ |B|.
10
Ù2u2 α=
(2!)3
5
10! . · 3! · 510
j2lvw2c2 ^ ì 3 < 2 Ù ^ ì 1 2 a ^ á r J 5 2u o 5 j ^ ì
10! (2!)3 ·3!×3!
3 5!
§1.5
2
25
a2u2}2~ ^ è
|B| = 5!α = P (B) =
ð[ñ
P (A)
|
P (B),
Ã2Å2Ñ2Ò ì
5!·10! (2!)3 ·(3!)2
.
5! · 10! . (2!)3 · (3!)2 · 510 5! 3! P (A)
Í2Î2£2b22Î Ã2ÅO _2p ÷ j ]o \2¿ $2^ |A| 2 “ì ? 3 d j > ¥2c<2è 3 Ù ^ ? 1 j > ¥2c2è 3 Ù ^ ? 1 j > ¥2c2è 1 Ù ” c ì 7 c2u2_ [¤ |B| 2 “ì 3 <2è 2 Ù ^ ì 1 2è 3 Ù ^ ì 1 2è 1 Ù ” c ì d7 c2u2 _ y ø © |B| = a|A|, ãYÿ a 2 Ë , > ¥ 3 j ^ 1 j d 7 }2 2| 1 j2c ì ~ y [é222É í ~2½2¾ a= = = 20. P (B) =
5! 3!1!1!
|B| |Ω|
a|A| |Ω|
= 20P (A).
5! 3!
£2o Ã2Å2Ï 2 ì è2¢2µ P (B) c2p ÷ a2·2¸2}2~ y " # O $ % c %;¶ 6 <¶a¶·% í ~ %% %¡ ÿ°é¶ì¶³ Ç y ¶ » ¼ 7 ÷ j % ^ d 7 c;·;¸;};~ y Ã;Å ³¢ Ð _ d7 c2{;·2¸& Ì 2 ì;é;a ; \ ¿ £¢ Ð ¢¤<2a d 7 c2·2¸2}2_ y P (B) =
=
= aP (A) = 20P (A).
¥ ¦ 1.5 1. §©¨©ª©«©¬©©®©¯±°±²©³±´±µ±¶±·©¸º¹¼»±½±¾©¿±À 5 Á©ÂÄéũƩǩȩɱʩ˱²±Ì±Í±Î (1) Ï©®©Ð©Ñ (5 Á©µ©Ò©Ó©Ð©¨©Ñ©Ô©² 10, J, Q, K, A); (2) Õ©Ð©Ö (ש¶©Ø 4 Á©µ©²©Ù©Ú©Û©Ð ); (3) Ü©Ý (Ø©Þ©Á©µ©Ð©Ù©Ú©ÂÄß±à 3 Á©µ©Ð©Ù©Ú ); (4) á©â (5 Á©µ©²©á©ã©ä©å©ÂÄæ±ç±·±Ð©Ñ±Ô ); (5) è©Ð©Ö (Ø 3 Á©µ©Ù©Ú©Û©Ð©ÂÄà©Þ±Á±µ©Ù±Ú±·±Ð ); (6) Þ©é (4 Á©µ©ê©Þ©é©ÂÄà©Ø©¨±Á±×±ë©µ ); (7) ¨©é (Ø©Þ©Á©µ©Ù©Ú©Û©Ð©Âà±ì±è©í±µ±Ó±É±·©Û±Ð±²±×±ë©µ ). 2. î©ï©ð©ñ©¨©ò©ó©ô±²±õ©â±Âö±÷©Ê±Ë±²±Ì±Í©ø±®±Î A = {ñ©ù©²©õ©â©ú©û©Ó±ü±ý }, B = {ñ©ù©²©õ©â©ú©û©Ó±þ±ý }? 3. ®© ÿ ©Ø n + k ÷ ©Â n ÷ ©¾ ©  ±Æ ±² m (m ≤ n) ÷ ©Ø ²©Ì©Í 4. N ÷ ±ê±² ±Â ±¾±À±ù±ë±²±¨±÷ ±â Æ â رü ý±÷ ²©Ì©Í 5. ©¶©¸©Ø 2n ÷ "!©û 2n ÷ #!©Â §©¶©Ø©¸ ¹» ©¾±¿©À 2n ÷ !$©Æ %©À©ù©² !©¶ !&#!©ý ' Û (±²±Ì©Í 6. ©¶©Ø a ÷ "!©û b ÷ #! (a ≥ 2, b ≥ 2), §©¶ )©¸ ¹» ±¾ ¿±À±Þ±÷ !±Æ±Ç±È±Ê Ë©²©Ì©Í©Î (1) Þ©÷ !©² *©Ô©Û©Ð + (2) Þ©÷ !*©Ô©·©Ð
Y[
26
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©¶©Ø 5 ÷ *©Ô©É ,©²!©Â.-/±¨±ï “®©¯©Ó 25 ²©Ø©¸ ¹¿0 ”. ©Æ©ÎÄ¿1©² 25 ÷! ¶23*©Ô©²!©É±Ø 5 ÷©²©Ì©Í 8. ±¶±Ø± ¨ 45!±û #!±Â6±ß5!±ý'5&#!±ý'¼ú7¼Ó α. §±¶8±÷±À±ù%±Ø±²! Æ©Ï 9©¨©÷©À©ù©² !:#!±²±Ì©Í 9. n ÷ ;©» <©ê©¨ =©5 ©Æ±ù±Þ©÷ > ©² ±Û ?@<±²±Ì©Í ¼Ç A n ÷ <©ê©¨ B©" C Æ ©Ì© Í 10. D 30 ÷ !(©ç E©»©¸ 8 ÷ F©â G©Æ©Ç©È©Ê©Ë±²±Ì±Í©Î Ø 3 ÷ F©â©Ó F©Â Ø 2 ÷ F â©É©¸ 3 ÷ !©ÂÄØ 2 ÷ F©â©É©¸ 6 ÷ !©ÂÄØ 1 ÷ F©â©¸ 12 ÷ ! 11. §©¨©÷ n ©ê© ² HI©¶©¿±ù±¨©÷±®±¯±Ó r ² 0J©Â Æ L > ©² N ÷ ©¶©· K L 0J©¶©²©Ì©÷ Í M ©Î (1) )©¸ "¹ + (2) Ø©¸ "¹ 6©ß©Ã©Å Î a) n = 100, r = N = 3; b) n = 100, r = N = 10 N©O  7"PQR©Þ 3©¿ 0S%1©²±Ì±Í 12. ©¶©¸©Ø© #!± û 5!±Â§±¶ )±¸º¹¼» 8±÷±À±ù %±Ø±² !Äö±÷±Ê±Ë±²±Ì±Í P±®±Î (1) T ¨©÷©À©¨ù©4 ² !© Ó "!+ (2) Ï 9©¨©÷©À©ù©² !© Ó 5!U 13. ©¶©¸©Ø© ¨ 4 "!±û #!±Â§©¶±Ø±¸º¹¼»©½±À V!WX±Â V!±Ð±Ô©T ²±Ì±Í±·±¯ Y . 14. ©¶©¸©Ø a ÷ "!©û b ÷ #!©Â §©¶ )©¸ ¹» 8©÷©À©ù %©Ø±² ! Æ k ÷©À©ù©² !©Ó !©²©Ì© Í 15. ±¶±Ø a ÷ 5!±û b ÷ #! (a 6= b), §±¶ )±¸º¹¼» 8±÷±À±ù %±Ø±L ² !Äö±¨±÷±Ê±Ë±²±Ì Í P©®©Î (1) L © ¨ NZ%©À©ù©² 5!©ý &#!±ý '¼Û (©Â (2) ©¨ NZ©¶ [©È©² !©ý &#!©ý ' Û ( U5±Æ±ù \4±Ê±Ë²©Ì±Í 16. ]©Ø 2n Á ^_©Â Q©Ù©Ã©Å `abc 1 d 2n, à©Ø 2n ÷ ef©Â Lg©Ã©Å `±Ø \4bc ;©» D^_hef©i 2± ÷ efh 1 Á ^_i©Æ 2©÷ ef&h × j¼² ^_±² bc±ú©û ó©Ó©ü©ý©²©Ì©Í 17. Þ ©Û klm©»©É©ð©ñ©¨±ò±ó©ô±² no"©Æ±Î L ɱð±ñ n ï©ú 9©Â Þ ©ñ©ù©Û©Ð±ï±ý p Ù©²©Ì©Í 18. D©¨©ª©«©¬©©®©¯©°±²±³©´± µ qrs9t±ê©¨ u±  ±Æ©Ç±È±É±Ê©Ë±²±Ì±Í©Î (1) Ï Q©Ù 4 Á v©Ó A; (2) Ï Q©Ù©¨©Á©û©Ï©È©Ù±¨±Á©ó±Ó A; (3) É A ú wwx©Û©Ð©²©Á±ý l. 19. 2 z ¨ yz{z| Ø N z÷ }zb zç Ez~z  ]zvzP{©Ø n y  r z÷ z z² }zbzWzX Î T 1, 2, · · · , n y©Ã© Å ©Ø r , r , · · · , r ÷ ©² }b ( r = r) ²©Ì©Í©Ó 7.
1 2
n
1
2
n
j
j=1
r1 r2 rn CN + CN + · · · + CN . r CnN
20.
21.
22.
23.
©ù 17 ©Â ש¶ " 10 ©Â# 4 ©Â 3 ©Â L ¶%©Ø©² ²©Â$©¾D.\4 ±¨©÷±Ó 4 "©Â 3 #©û 2 © ²© ÂE%± ²±* Աǩý1© ²±Ì±Í±: îU D n |© ꩨ© ¨© Þ© ñÂi 9D%©1 ² 2n ©¡ ¯¢;©Ã©ê n é©Â2©é©ä£©ê ¨©¤ ² “ ”, Æ©¥ È©É©Ê©Ë©²©Ì©Í©Î (1) \ 2n ©¡ ¯¢v¦§¨©©êª«©²+ (2) ó©Ó© ²© Ã&© ²± Ã±ä£ ¬· a, b, c, d Ó©Ü a + b + c + d = 13 ²©Õ¡®¯©ý©Â L ¨©ï°©µ±²©¶±Â Ƴ´µ¶©É ¸ a, b, c, d ¹#º»¼½ p (a, b, c, d). ¾¿ÀÁ¡ÂÃÄÃÅÆÇÈ»ÉÊË Ì Ã©ÂÅ ÍÎÏÐÁ¡ÑÒÓ ÔÕÖλ×ØÙÚ¼½ p(a, b, c, d), ÛØÜ (1) a = 5, b = 4, c = 3, d = 1;
(2) a = b = c = 4, d = 1;
(3) a = b = 4, c = 3, d = 2.
§1.6
ÝßÞßàßá
27
â ãäåäæ ä çéèéêéëéìéíéîéï"ðéñéëéìéòßóéíßôéõßöé÷ßøéùßúéûßüéýßþßÿéëßìßí §1.6
1.6.1 ø 1 ÿéþéï x, y z ÿ 3 ß ï!"ßù#$% 3 & '()*+ßÿßë ,-/.012 ï ù#$ 43 (x, y, z) 567 89ßï4:ßó 3 ;<=?> ÿßí !ß ó@ßA ùßúßÿ8ß9 ÿBCDßó %ßó
; <=?> ÿßíEFG!HIßþ:ßóJK x + y + z = 1 > ÿßí)*+ L 9$ A 67 3 & éù#+)*+éÿHMßïONPHM A QRS ïOTA 3
Ω = {(x, y, z) | x + y + z = 1, x ≥ 0, y ≥ 0, z ≥ 0} ,
@#UA
x + y > z, y + z > x, z + x > y.
y, z) | (x, y, z) ∈ Ω, x + y > z, y + z > x, z + x > y} , :ßòßóJK A x=+{(x, ÿßí)*+ (VWX 1.2). y+z =1 > Y éóZéÿßï/@#ßî[ (x, y, z) ÷ Ω > \] ^éïO_` .0 CaZb P (A) DUßP ø)*+ A ÿKcd)*+ Ω ÿKce?f4!ghiI jklm >n4o 12 ïp)*ß+ ÿKcßD óq Lebesgue r p@# .0 $ L(Ω) L(A) 67 Ω d A ÿKcßï!%s L ó Lebesgue ÿtu!ßóDA P (A) =
L(A) . L(Ω)
(1.6.1)
x yï z{|}~| vw ! Ω A y n
R ~ Lebesgue L(Ω) L(A) n
Lebesgue í 5 ïz÷ 1 ; ß C ï Ω d A óß ïp` S : 0 ÿ Lebesgue r Dßó ßÿ ÷ 2 ; ßC ï Ω d A óßN ÿJK X +ßï` S : 0 ÿ Lebesgue r DßóJK X ß+ ÿKc ÷ 3 ; ßC ï!N óc øßø L ß ` í 5 ï!ß ÷ 1.6.1 > A P (A) = = .
1.6.2 ¡¢4£¤ ¥§¦©¨ª 6 S« 7 S e =¬ ¥ß® ï!¯ ¤°± ÷²®³ ´ 10 µ!"¶ 0 ùß÷²®·ß¸ ÿßë ,- # (x, y) 67£¤¬ ²ß® ÿ S= ï!N¹ 1L 9# A 67£¤ ÷²Ω®=·{(x, ¸ ÿy)|Hß ß M 6 ≤ï!xN≤A 7, 6 ≤ y ≤ 7} , vw
n
(1.6.1)
L(A) L(Ω)
1 4
A = (x, y)| (x, y) ∈ Ω, |x − y| ≤ 61 .
28
ù#b £¤\ Zß÷ 6 S d 7 S e Âï Áßù$ßðßñßëßìÃeÂÄÅßï ]' ^ß 5/6 ÿ É*ßø Ê)*+eË
ßó Y4ÌÍ
ö
c
5 2 6
L(A) = 1 − L(Ac ) = 1 −
L(Ω) = 1, (1.6.1)
º?»4¼ ½¾¿À =óß¬í ²' ®ßï! @#ßÿîÆ[Ç +ß(x,ïÂÈ y) ÷ ΩóÉ>4\* Ω @1# A (VWX 1.3), L(A) L(Ω)
=
11 36 .
÷ þÎÏ > ï .0Ð $Ñ L(A) = L(Ω) − L(A ), %iéðéñÉÒéóÄÅéÿ é ÓÔ iß ë * 5 ß ï þÎHIßòßù# 6 Î P (A) =
11 36
=
.
c
L(Ω)−L(A) L(Ω)
.0ÕÖ× íØÚÙ ÛéëP (A) H=Iéþßóßí r= 1 −ïÜPË(AÝA ). P (Ω) = 1, @#²éø Í Þ ± ó r ûßßÿßíàá
1.6.3 ÷Úâ ãéþäå 3 A, B, C, " ∆ABC æ*)*+éÿéë ,ç- $ E 6ç7 ∆ABC çæç*ç)ç*ç+ ÿçHçMç!è ÷ ÿçéçê ó L ñ 6 Î Ω ÄçÅ ùç#çëçìíâ ÿçîçï ó 1, âñðç O. ó ∆ABC çæç*ç)ç*ç+ øçòç E. 90 , È%éô øòõ AB, BC, CA ÿ \ó π. ABC, BCA, CAB \ó ÄÅßù#ö÷ø?ù4ìßíßï Y ²®úû?â4ãßï?â4ãüÉßí & 2π ÿ !Åý ²þß ïÿþþ þ þ x, y z ÿ 3 & é ó ± % 3 & é ÿ °ó π, N ∆ABC éD óæ*)*+ é% îéí 5 ï 1 ù Õ Ω E 6 Î 6
6
c
_
◦
6
_
_
Ω = {(x, y, z) | x + y + z = 2π, x ≥ 0, y ≥ 0, z ≥ 0} ,
0 < x < π, 0 < y < π, 0 < z < π} . Y ßóA={(x, ßy,ÿßz)ï!| @x +#ßyî+[z = 2π, ÷ Ω \] ^ßï!Á Y4ÌÍ (1.6.1) (x, y, z) L(E) L(Ω)
. J þ K þ þ ÿ J þ þ É ï ²þJþKþþþ í þ 1.6.4 = a ÿ (l < a), " dÉ· ßÿßë %éê Buffon éßê ï óßë m > ÿßíéê (VWX 1.4). ,- # E 67 dÉ·ß ÿHM .0 5 L ñþÎ Ω E. ¹ 1 ï ßÿ ù Y :ßÿ > ¬ ÿÉßÿ ρ, #:dÉßÿ* θ ì!@# Ω = (ρ, θ) | 0 ≤ ρ ≤ , 0 ≤ θ ≤ È dÉ·ß ï!PÝßP ï ρ ≤ sin θ(VWX 1.5). @# .
P (E) =
1 4
=
a 2
øßî[
π 2
l 2
@# Y4ÌÍ
(1.6.1)
(ρ, θ)
L(Ω) =
πa 4 ,
÷
Ω
L(E) =
P (E) =
sin θ .
>4\R] ^ßï!@#$ßðßñßëßì!¹
E = (ρ, θ) | (ρ, θ) ∈ Ω, ρ ≤
L(E) L(Ω)
π 2
0
=
l 2
l 2
sin θ dθ = 2l .
2l πa .
l
§1.6
ÝßÞßàßá
29
¨K ë m > ÿßíAéêßï!@" Bertrand # m !:ßó$% l& 5 h Bertran 1889 '()5 ÿßï Bertran *) Ñ:ßÿ 3 ô çÃ$ßï!Ë ¬ Ñ 3 ôßç,+,é - ï%D,. éí ¤,/ P S ÿéë m > ÿßí ë0 Ç,$1 R Ñ,23Ü_ `4 # m
1.6.5 ÷5 â64÷ß7 íß8 ï!"8 g √3 ÿßë ,-/.0 # E 67 8 g √3 ÿHM!éßê ó L ñÎ Ω E. 9,:,; ,,<- ,=b,é8 ÿéí,> A n o åéì ï éê j é ÷Úâ éã þå,é? í,> B. é ó Ω éD ó,@Úâ ã Y ,5 Oâ ÿA6CBÆ)*é+ ÿ' ø √3, @# Ô # í,D,7,5 Oâ ÿA6CBÆ)*+ ∆AM N , NPÝ,P,8 AB d' M N ·, é A S ïE8 AB ÿ # g √õ 3, Èï!` NS A > B õ5 Mâ Nÿ?þéâ4ï ã @# E éD óõ M N(V WÁ X Y ðß1.6(1)). L 67 L(Ω) = L ( )= 2π, L(M N) = . ñßëßìßë ÌÍ (1.6.1) _
_
_
2π 3
_
L(M N ) L(Ω)
= 31 .
9F; ,<- ÷5 â64åìßí & Éï M N , ±GH d M N I Éßÿ8 AB, ` S 8 ÿ AB ÿ > d?Kâ4ð Tß÷²ÿ Éïßþ @#ßùï8 Éï Mÿ N 7 g Ω. √¹ 1 ïPÝP8 AB O ó S AB 3(VWX 1.6(2)). @# > K P (E) =
1 2
ßó
E = K| K ∈ M N, |KO| < 21 .
L(Ω) = |M N | = 2, L(E) = 1,
Á Y ðßñßëßìßë ÌÍ L(E) L(Ω)
= 21 .
L(E) L(Ω)
= 41 .
(1.6.1)
-
9,J,; ,,<- 8 AB ÿ Y :éÿ > K ÿ , Ûìéï ¹ 1 ï PÝ,P > # 1/2 îïßÿßçð?â4eK6 S ïL8 AB ÿ g √3. @#ß÷%sßï Ω D K ó@5 â ï E Dßó# îïßÿßçð?â ï L Dßó: 0 ÿKc (VWX 1.6(3)). Á Y ðßñßëßìßë ÌÍ (1.6.1) P (E) =
1 2
%éô$ßçÃ,$ ¬ ßç8 m ÿ,M,Nßï .0,O ó,Pßí,Q¸ ¬ SR,T,UßþÎà +ÞVßïù 1 1 R ß ç8 m ÿW_ßó - êYX > ÿ “÷7ßí8 ” ÿZ[\]^ßï _ Èßù / q7_ßôßçaÃßï iÈ`a / î[ <= Ω HM E ÿßçaà % ç ÿþaþà / êbX > ÿZ[þ]þeþ®7þÑþ ç ÿcd ï.þeþþþ ç ÿ ëþþÏ ééê ï_`,1 R,),e ôß çéÿ8 m òDf # ÑéïÜ_: 0 HIßþéó / ßç éê@ *) ÿ+- gh 1.6 1. iLjL k Ò 1.6.2 ÈËmlLnLo 3 pLqLrLsLtLuLj Ówv ÙÛyxyzy{y|y}y~ Ü (1) 3 pLqLLL ÖLL|L}L~L (2) L
LnLLpLqLLy Öyy|y}y~ Ó P (E) =
º »4¼ ½¾¿À ? 2. LSLLLLLkLyLyÓEiyLyyLnyyykLyy|LyySyyLy y¡y¢E£¤ ¥ SL L¡L¦L§L¨ykLyyy© 3 ¥ 4 ªmOÓÙLnLL L¡Ly¨y«y¬L Úyyy|L}y~ Ó 3. ®SL¯Ð S | 4ABC SL°LL± P , Ù 4P BC |LL¯LªL² S/2 |L}L ~ Ó 4. kL³L´ÖLLµLL± A, B ¶L·LL¸L¢m¹LLµLL± C, D ¶L·LL ¸ ÓÙL¸ AB ¥ ¸ CD ºL» |L}L~Ó 5. kLL¼L½LnL¾L¿LÀLÁLÂL|LÃÖyÄLÅy°LÆyLÇyÈL É Ð 1 |LÊLË ÓÌvLÍL¢ÌÎL¿LÁLÏLÐ a ªL²LÑ
LL¢mÊLË ¥ ¿LÁLÒyºy»y|y}L~yªy² 1%? 6. kLÓLÔ (0, 1] SLµLLpLÕL ÚLÛLÜLÝ ² 0.2; (3) LÞLL¢ ßLÙLàLxyLÖLáLzyâL{yã |y}L~ Ü (1) LÕL×LØLªL² 1.2; (2) LÕL×LÙL| 7. äLÐLå l |LæLçLLèLéL· 3 çL¢êvLàLëLxL§LzL{L|L}L~Lì (1) LLLíL·LLpLîLïLÀL (2) LLðLñLÐL|LÒLòyó . 8. kLÓLÔ (−1, 1) ÞLLµLLÕ ξ, η, ôLõLöL÷L¿Lø x + ξx + η = 0 |LöLùL¢mvLàLëLxyzL{y| }L~Lì (1) LLLúLûLÕL (2) LüLLúL¾LÕLã 9. kLýLLÞL½LnLLþLºL ÿ LÈy|Lý yÈLæy ¢ yü yýL pLåy LÖyÏLÐ aØ b | LÀLã ® ¥ ýyyÄyÅ y° yyÇyÐ yå 2r | 2r < a + b − (a + b) − πab , vyà yy
L½LÈLæLºL»y|L}y~yã 10. LýLLÞL ½ ¥ LÔ yå a Lý LÈLæL¢m ® Lý yÇLÈyÉLå R LÊLË (R < a/2). LàLÊLË LLÈLæyºy» yã 11. ! "! #$%&')(*y ð +yè ,-y.ã yà -/$%&yð yã 12. ( LæLçL Þ +0 12 3 ,-L.ã Là 3 3 ,-/45,-67yã 13. 8 Lå a + a LæL ç 9-:8 ;yå a < a 5=L>ã ( LæLç +0 12 n ,-L.ã LàLì n ,-L ð ? m ,-/8 Lå a =Lð Lã 14. ( ,$%&L ð +0 3 ,-'@Là ALü &:BCLîyï &6D-Lì (1) ELîLï &F (2) $LîL ï &F (3) GLïLîLï &Lã
30
2l 3
2
2
1
2
1
2
1
H IJKJLJM J NPOPQPRPSPTPUPVPWPXZYP[P\P]PUP^P_PXZ`PaPbPcPdPUfeZgihPjPVikPXZlPmPn oqpqrqsqtqsqu Uq^q_qvqwqx sqtqsqyqz Uq{q|q}!~qqlqmqn yqz
{q|q ZPYP[PXPPPPXPkP\P]PX`PaPPnPxP`PPPPUPPPPPXPPPPP `qaq^q_qUqqqX!Qqqqqqq qqqUqNq¡q¢q£qxq¤qdq¥q¦qUq§q¨ª©qq« pqr ¬i UiViWi} limini®i¯i°²±)Yi[³´PQi yizqµi¶ X*·²³e.gP¸i¯PQiRPSiTPxP` aP¹Pº³»)UP°P¼P½P¾P¿PÀPUPPÁP} lPmPnPÂPÃq^P_PÄPPPX!q`PÅ r °PÆÇÈPUqÉqkPUq} 300 PÊPËPX!ÌPlPm nPÍPÍPÎPÏPÐPXZÑPPÒPÓPPÔPUP°P¼PÕPÖP}ZQPPP×P|PØPÙPXZÚPÛiÜPÝPÞiÞPßPßPU PÁPVPàPÒPÓPÐPXZáPÄ r PPâPãPäPåPUPæPçP})è)PéPêPâPãiëPìPXZíPÝiPîPU p ïPX´QPPðPñ r äP³»)UP¥P¦P} 17 òPó ÐPX´ÒPô³»)UP°PõPöP÷PøPUPQPùPú³û)üP Uqýq[qþqÿq}!ÌqÐqUq°qõqöqUqýq[qþ r ö
UqnqX ~ §1.7
§1.7
31
}ªèPÕP¹PlPmPn³»)UP°PõPUqlqX!ÜPÝq°Põ “ ¾  ” RPlPmPUPãP}Z ¬ UPÉ!PVPk³»)XZöPPP["PnPÅ ¾PÂ#iæPçPX%$ PnPÅPlPmPn³»P& ¼PlPU'(PdPæPçP}%)P~PXZöP½*PQ+PÅ,.-/0iUPð1P}%2 34PP³»)°PõPQPUPð1567 ð1" ,/0P8 ý P ¢9:P8 ý P ¢9:P; m Fermat, Pascal
Buffon
4040
2048
0.5069
De Morgan
4092
2048
0.5005
Feller
10000
4979
0.4979
Pearson
12000
6019
0.5016
Pearson
24000
12012
0.5005
Lomanovskii
80640
39699
0.4923
< = t>? °P2 üPPUPðP1 }~@PÜ 8,-/0³»9:PUP¢8PýPXCBD fn (A) =
A
3A,9:PXÜ
Nn (A)
3AP
n
Nn (A) n
4.Ei¯.9.:iU.i¢.;imi}è)Ô.F3.G³»´UPý.HIiXJ9:PU.P¢.;Pm f (A) ú.Ki viX ·.O.,.-.i 8 ý s iXPi; m f (A) 4 siµ M 0.5. Q °.R.S.3UTV7 (1) 0.5 L.M.N ,-/0PUPð1³»)X% PP¢9:PxP¢W:PU ¾PÂ#.XYPZiPU[ (2) N ¡Rq \ ^q¹qUq¾qÂq# q°q] ¾qÜqVqà^q_ U`aqb qUq_ XCqc Tq u ýq_ Ude ð³ 1 »Pf ÅP; m f (A) Wg t [ (3) P; m f (A) ¾PÜP®P¯PlPm P (A) U Mhi X ·OPÌPð18Pý n j >Pu ÐPX Mh k^PT Ã k } l PX QPP$ ½PÂP½mPn ÄPÔF3³ P F »)UP½opqr7tsu “,-P8 ý s PX ;Pm f (A) 4 sPµ M P (A)”? Qvw P½PÂP| “ε − δ x ì ” ty PF }CPz ¯ = ½PÂP{n|PU ε > 0, } ÄP°]fZPý n , ~ p P° n > n PÂP¸ n
n
n
n
n
0
0
|fn (A) − P (A)| < ε.
(1.7.1)
RSPÔPXZQPP Qv P$ ½P Q ]nPX Qv U “;Pm f (A) sPtPsPµ M P(A)” U {PÌP “NPO n U
u X (|f (A) − P (A)| ≥ ε) ^P¹PUP¾PÂ# sPtPs ”. ¿ "P X “NPO n U
u CX R\ {|f (A) − P (A)| ≥ ε} UP^P¹PlPm n
n
n
û)
P (|fn (A) − P (A)| ≥ ε)
(1.7.2)
° t XQP4 r °]PÜ N Uq³»7°: “;Pm µ M Q ilim ” 3U´ T limii°.].`.a.biiX*·.O.;PmP¾iÜP®i¯PlimPU Mh.i [Ji°.:PX ;Pm µ M PlPmPU ÷fPÅ “lPm 0” ty FP}!PPX!QPP½PÂ 0 .”
32
½ æP°7 “¨ ¡DPPlPm ”? ¢ PÔ Bertrand £ nPUP¢PX ~ p °PõPQPPÌPÐ P Uilimin²»´Ui°iõil.ix.iãPÕi¹ r.¤¥ }*iPX QPi½ p ½¦.§.:P Q ¼.¨:PX ©Pä ªPU «PãP%} Pä ªPU «PãPÑPöP°]PX Q 4P¬PlPmPn Z÷PUiPn®¯i}Z Êq U °±qýq[qþ u TqÔqX Hilbert ²³ qU 20 òqó {qäªqU 23 ]qýq[qæqç 1900 »)´ X 4µ Q ]PæP ç ¶PP³»)} ½PÅPX Hilbert µc¶PPýP[PÖPPæPçPR³»)UPX ÌP Ð ·¸PöP Q ¹¦PlPmPnPP ° ]PýP[ >º C X zP ¯ c·¸P ö opPUPýP[PP n ®¯P} lPmPnP U opPUPýP[PP n ®¯qP 20 òPó 30 Ê »¼YPUPC X cP { ½¾P KolqU Àqqd ÁÂq} Q ¼ Àqqd ÁÂqU ¿ Ã
½
ù ÄZ
nqx Å ^qn
U mogorov ²¿ ^q_qC X $Æf r lqmq n Çq ¢ »qýq[q c >º U ÈÂq} = Éq 2q ° ÊÌ » ËÍ Kol.U Àii.d Á.Âi}. Q ]ÀiPd Á.Âq2iX ² öPUPlim ÎP.ç p Ä r opPU mogorov ÏFPtX ÐÑ “;Pm µ M PlPm ” U ( X Q 4 ~ p QPP¾PÜ yPzP ×P| Q ° R S t ä ªPPPæPçP} ¢P 4 t ËÍP³»)UP ° ]P{P|P} ÒÓ ) 1.6.4 »)U ,ÔPæPçPX! B v p ÔÇÕÖ×ØÙÚqUPlqmP¯ P (E) = ×P| Q ° Û@Px “;Pm µ M PlPm ” U RSPÝ X ÜP ¾ Þß7 Ñ ,-P U 8Pý n j . > PCX ;Pm f (E) 4PT j >PPµ M PlPm P (E), à ì qPX!~ @P n 8,-³»)CX Ô Ç×ØÙÚ r m 8PCX BDPÌ n j >Pu CX 4PTPö 2l πa
n
n
áâPö
mn n
≈
2l πa ,
QPù4æãrä °= Öq¬PX!¸¾qÕPÜõfqÅ u {_çPdUeè,éPÔq} Xªè¼ÔPFãPÀåEP¯ π U Mhi } PQ ãP4q}¯ è)= Monte Carlo iãi¢i² oipiriy e ð.1i¾iÜ.fiÅ..i¡ tê.ë Si¢PQX ² Ü Monte Carlo u _.d.i ì |PXCP) ~P¾PÜP|c t P°PõíîPýP½ï3PUYð > X } z UP ; m µ M qlqm ”, 3ñT r lqmqU`aqb qXC$3ñT lqmq¾qÜfqÅ
ð1 t 1 q “ ò }%l Q ÑPPæPçPUP°]:P}Z{PÌPXZ·P½P ² öPUPlPm PÂ.fPÅPð.1 t 1 ò UP}VP ) ~PX´Õ]ódPô QPb ºPÐPõ Uö “Pb º 3 ]P÷ UP¾PÂP# ½Pø Å 15%” » U 15%, P 4 ½PP°P] ¾P| u _dPe ð1 t P Ü1 ò UPlPmP} Q ¼ö tù Pú ¹PU úP[ÞûPX%úüP`1PÜPÝPôPQôýPU r äPx þ öPXZ*.ÿPöaißPX ² Ü öPQµ Q RPlPmP E ¯aPlPmP} ÜPÔPU w p öPõP XP ÂPöP u þPPlPmPnPU r äP} π≈
2nl mn a .
§2.1
30 !"#$ Kolmogorov %&'()*+,-./012$34 &5-565758:95;5+5,5-5<5*=?>@%5A$53454B5CED5FG5HI%5&'5()5JK54L +5,5-58:M5N5O5P5Q5$5+5RS5&-58ET5MN5*45L+5,U5V$)5UW5XY5KZ5[$ 6 C Kolmogorov %&'()\"#G]^-S_`-$67a$Ccbdefg h 7 {4 |i } 0(j~k8Tl\3-}8nmpoqp$qC rstvu@wxyCnefzF45ijkl538nD[A _5`5-5$555s558:+5,5-$5%&5'(5)5
58:5j
i5t\5_5`$&-s+,&-0C 20
5 =5?8:5?5W555 5\¡5¢£5¤$5¥]58EQ5\5¦5~vN §5¨ T55N5
§5¨ $5=5©5ª5f5$]5^C:5«¬55 8:\*50W5Q5$5® N¯$g§°8±+,C²´³µ´¶8·ef } A ¸¹ 8$»ºn$´J=´t´\ [N¼½ P (A). G =v@8¾-i¿©+,ÀÁC Âà +Ávu@wÄÅ8ÆD[ÇȽ § A S¡¢£¤ Ω @$¡¢I3 } 0CËÊ@ÌG Ω =ÍDFFÎI¡¢8! }Ï Ω $Ð |A| S |Ω|, Évu@=vu@t Ñ ¥]8Ò }Ó § +,C Ñ +Áv@8Õ\[ A S Ω $ Lebesque _` L(A) S L(Ω) svu@C G Ô Ö ×i8 Ï ÌØÙ8Q$ Lebesque _`t\Ú`Û Ï ÌÜÝaÞ£¤v@$ßÕ $ä Ô Ñàá 8Q$ Lebesque _`t\ÝâÞ(âC! } Ñ´G à´ á=v@zFã êëiêå¡o$æçCÆFC=èì \á8í±î9 Ç ΩÂ\ï Ü$ÝÜaÝ $à=á I8ÆßQÕ$$ÝÔ â\ðñ8VQ´½$$ ¥´(]´GT_é´`\ ò@ó § Lebesque
_] ). efôQT½õ 8ömoQ$®+,t 𠽧 s0C*0÷HIøù8·´tDN´ô´´ δ/* Ω @$=ì } ñ ½ Ýâ$¥]C ú5û 55ü5[5ý5þ5ÿ | $5+,5ÀÁ58:üé5ã ä ©5$5C:! } [ Ï åo\ õ § =ìß/C §2.1.1
33
34
σ Gÿøùv@
Nô¡¢£¤ Ω $=I¥]Ò½õ 8! } 5[5s5¾5-5e Ñ /5555 5$C ²5³5µ5¶85 } ô Ω $}5ì& 5¥5]5½ õ Cc*d[s"#=ì!Õ8c"Hì!Õ[#$%8 Ì'C () 8[ô Ω ½õ 8+*J*Z ´Cb´*Q Êö=,´N´$´¦ ~ªf-<8bd=/®8±F P (Ω) = 1. /.´8e´f § Ì´«´¬ $/0´[´8[´ô Ω $´¥´] E ½´õ´´ ´8m´o´Q´$/1´] E T½õ} 8cb§ *Q¸¹ E
®C Ê@Ìô E ½õ 8c¶ E $}®+ ,§ P (E) \ } ½ s$8HTt234 E
®$+,8± P (E ) T\ ½ s$C! E T=/\ C 5 8 ef {E , n ∈ N } \=6 8 mo S E ¸¹Qv87#F=I ®8! } S E T\ C ea 59 ß/Ò\:;^&$8 ¨ GôQ<Ks= ô Ω $ } õ* $¥]$>(?õ F, E ∈ F ¸¹¥] ä E \5 CA@ F t\vÊ Ω @$=ì¥]!B<$ “¥]© ”. v@C $ 9 ß/\= §2.1.2
c
c
c
∞
n
∞
n
n=1
n
n=1
(1) Ω ∈ F;
ef E ∈ F, mo E ∈ F; S (3) ef {E , n ∈ N } ⊂ F, mo E ∈ F. ¨ G´$´ø´ù´\/=\/D´D´[´a/E 3 9 ß´/´t´¼´0GFc4´i´j´k´l´3´-´$/H/I´x´y JLK H´I´ø´ù´Cb´* _´`´- ö$´´´s´´8+M/N´a/E 3 9 ß´/´$´¥´]´© òöó σ O Þ σ 38QPFÿzF< § $´¯/QCH´ì´¯Q/N }R/S Q´NM/N´´«´¬ +,$0[CzF4ijkl3-$HI8 } KÝ$¾-v@0Hì¯QC ¨ G´´´t´s´¾´-´G´+´,´«´¬ öF/´ì/0 Ó 8+$/M/N´a/E 3 9 ß´/´$´¥´]´© Ñ MNHì0 Ó $C F \e § 8´Ê@aEß/ } W 8 Φ ¸¹
N 8öQ@G F @Cö
T U § Φ ∈ F. ja8ËÊ (1) W Ω ∈ F, ÉvÊ (2) ±W Φ = Ω ∈ F. e5f E , E \5¿5I55 58 m5o 9E ∪ E ¸5¹ E§ S E 7#5F5=5I55®5}58 b5d E ∪ E T@5\55 5CWVX5aE 3 z5F< H5=558 è5} \555¶58 a 9 U § E 3 ß5/? } H5=55s5C:5j5a8 ÊÌ E , E \55 58:! Q55Ò5G S F CZY ÊÌ Φ ∈ F. ! e5f[ E = E = · · · = Φ, m5o?Ê (3) ±5; E ∪E = E ∈ F. H=ª-T Ï FÎI E , · · · , E $] S E <#C\HI }^]8_8U` C c
(2)
∞
n
n
n=1
c
1
1
2
1
2
1
2
2
1
3
2
4
1
m
n
n=1
∞
n=1
m
1
2
n
a8bcdef 35 G 3 9 ß5/?z5F5Ñ ý5þ55 5$9 g58:èU \5§ 5$g¸5¹H5ì5 hi5®8Z@ T5\55 5C m5o5e Êa(E ) 3 ß5/ H5=5jkFAl {E , n ∈ N } \5=65 8c±l {E , n ∈ N } ⊂ F. 8cvÊ (2) WF {E , n ∈ N } ⊂ F. .8 Ê û 8 É?Ê De Morgan ñ5Õ5S (2) W T E = S E ∈ F. S (3) W5F E ∈ F; m HtU no86I $g]´TpÌ F. ef[ E = E = · · · = Φ, Õ WFÎI E , · · · , E $g]pÌ F. m û 8´´s´´e Ñ/U § ¿´I´´ ´$/q´ ]/p´Ì F. ´j´a´8e´f E , E \´¿ I 8moQÒpÌ F. Ì\ E ∈ F, $ E − E = E E ∈ F. Ht¶@8@D[ F MN0!6 § $ 3 9 ß/ (±D[ F \=I σ O ), moG F @trs0Gt;2ua!¶$!F C bd8 D[ô F ß/ á <$=I σ O 8 "Dô F @$<vvò@ó 8 tN *v Ê Ω $=ì¥]! }RS «¬+,$0[0C+t;8ôH¡$ σ O F ò@ó σ . *0 & Ì úû '8w § eK/u= xy 2.1.1 z¡¢£¤ Ω $=ì¥]!B<$© F ò@ó σ O 8efQ MNeK 3 9 ß/= §2.1
n
c n
n
∞
n=1
c n
c
∞
c n
n
n=1
1
m+1
m+1
2
c 2
m
1
c 2
1
1
2
(1) Ω ∈ F;
D[ E ∈ F, tF E ∈ F; S (3) D[ {E , n ∈ N } ⊂ F, tF E ∈ F. hiTôaÝ$¾-ªf<</&$ á{ = x| 2.1.1 l Ω *¡¢£¤8ef F \v@$ c
(2)
∞
n
n
n=1
1◦ Φ ∈ F; 2◦ 3◦
ef e f e f
{En , n ∈ N } ⊂ F,
mo
∞ T
n=1
{En , n = 1, · · · , m} ⊂ F,
mo
En ∈ F; m T
n=1
En ∈ F
"
σ
O 8Õ=/F= m S
n=1
En ∈ F;
mo E − E ∈ F. §2.1.3 }~ σ Ï σ O $B<õ0=ìÕ¯$ß/8 0[
= @ Ê Ì / u 2.1.1 D\ 8Q$uCja8+/H´ì´ß/´8´ } G/h=´I¡´¢´£¤ Ω 8B § ÿ
h$ Ω O sC ) =ìP($ σ O $¥C yW8 O {Ω, Φ} t\=I σ O 8nb*QMN/u 2.1.1 @$ 59 ß/CnH\=I Ü$ σ C 4◦
E1 , E2 ∈ F,
1
2
MN/u 2.1.1 @$ 59 ß/8 e f A \ Ω $!F¥]$>(8@mo A @ ! } Q\=I σ O ÂC à H\ Ω @$=Img$ σ O (2O ± Ω @$Q σ O >Òr +Áv@8t\H¡ σ $C G A ). eG =8@Oef F S F \ Ω @$¿I σ O 8@" F ⊂ F , mo} t¶ F \ F $¥ σ 8 "¶ F u F °8 ÞI¶ F u F 8 T ¶ F u F gÞC e5f555G555¦5~?8:D=5© ¨ \D5®8Z$p} Ì5H© ¨ $5!O F NªfB<¡¢£¤ SΩ $=I:ÜO ¥] A, mo} t ô¨$ σ * {Ω, Φ, A, A O} (
T~ H\=I σ ). H\=I s¾-d© ® D$m°$ σ C eføùýþ ä ¿© ¨ 8+pÌQ$} !FN´ªfB´<¨/¡ ¢´£¤ Ω $¿I ´®/D$/m´° :ÜO ¥] A S B, " B 6= A , mo s¾-H¿© $ σ \¡$j^F () 8 Ω, A S B Ò@p5Ì σ O F, " F ü@rs?ÊQ5 § 58 õ5=,5 N$g§ 8cS1'½!; ä û5$Ï !F$]^ (Ω $¥] ). Ì\ () ti1' Q55õg'5½58E;5WÏ AB, AB , A B,} A B , A ∪ ½58E; Φ, A , B p5Ì F, B, A ∪ B, A ∪ B , A ∪ B pÌ F, è\ü
¼8b* Hì¥]ü õ/g8· ä S1'½8Ì\¨ Y; ¿´I´$´¥] AB ∪ A B S AB § ∪ A B, QT@} p Ì F. 7dä 8 ÉT§
Ntiõg8 S1'½; Q¥]0ä C ! v@ Ê Ω, A S B } 8 õ=,N$¨g 8 S1'½!N;O $!F $5]5^ (Ω $5¥5] ), $5 5s5¾5-5H5¿5© 5®D$m°5$ σ =5Ír s 16 I 8Q\= 36
1
2
2
1
1
2
1
2
1
2
2
1
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
{ Ω, Φ, A, Ac , B, B c , AB, AB c , Ac B, Ac B c , A ∪ B,
Ac ∪ B, A ∪ B c , Ac ∪ B c , AB ∪ Ac B c , AB c ∪ Ac B } .
ä 0 σ O $P5(5C z5F545i5j5kl35-$HI8 5 t 5 i 5 H I 5 5 ¥ 8 5 5 } HI¥v8
= 0 σ O $¯QCHI¥n/o´´8Z/ w´/$´=´ì ]^ § 8Æô “1Sg8Æ ” '½=
¡K¢8£ ä O
N; ä $]^*¤C d ! F$]^ (Ω $¥] ) B} <$]^©M\=I σ CËÊ@ÌGHI&¥v@ä8+m ¥ i § w $]^DFF¥ ÎI§ 8c! Dõ0FÎ. “1Sg8c ” '½ 0 !F$ªfCnefm w } $]^F6I8nmotZõð5Î.18nFÎg8 6g8FÎ86 þQ$¦^'½M¡C *0 & Ì úû 98w § eK/u= xy 2.1.2 z Ï !w § $=ì]^!õ$ êë 1´8+/gS//'½ } þ´Q $¦^'½§** Borel '½C
a8bcdef 37 H=/u8 σ O t\G Borel '½JK¨©$]^ (Ω $¥] ) ©C @ 8 ä üF=ì § σ O @!F<v$ªñC«Ñ e8 G¬M$¥v@8 e f2 eK®I]^ AB, AB , A B,Ï A B @Ð ¿I
¯g8Ï"Q $ ´]´t´\ Ω, ´´ô´áH´{ ¡´$´=/-´]´^/*´* }³Ω & $´=´I±ä °/² . m´o´t´D´[ Ç $<võ=,N $'½8t ; !F 16 I]^C } a!¶ ä $vÊ 16 I B<$ σ O 8 \ w/$ Ω $¿I¥] A S B § 8+tiõ Borel '½; ä $8ôHI σ O **vÊ {A, B} ®<$ σ O C =F= xy 2.1.3 ef A \ Ω $=I¥]©8movÊ A @$]^õ=,N$F Î.S6. Borel '½!; ä $ σ O F **µ´ A ¶· σ , ?õ F = σ(A). O }O S @8 σ(A) \ r ¥ ] © A $m°$ σ 8@"Q\r¥]© A $ !F σ $gCL@ σ O $gü\ σ O Cö4ijkl3-$HI }^]8_8U` § Hìª-C ¨ Gs¾-j Øa$ σ O C ¸ 2.1.1 z Ω ¹*j Ø8+[= x)| x ∈ N } , A = {(a, b)| − ∞ < a < b < ∞} , S 8= σ(AA ) == {(−∞, σ(A ). º = ÇÈ? F = σ(A ), F = σ(A ). () 8 Ï Ð Ñ j3 x, ÒF S (−∞, x) = (x − n, x), } Q\6IF»¼½¤$]8! §2.1
c
1
c
c
c
2
1
2
1
1
2
2
∞
n=1
±
(−∞, x) ∈ σ(A2 ) = F2 , ∀x ∈ N ,
bd F = σ(A ) ⊂ F . ¾ J8 Ï Ð Ñ j 3 a b, a < b, ÒF=
A1 ⊂ F 2 ,
} þ
1
1
[a, b) = (−∞, b) − (−∞, a) ∈ σ(A1 ) = F1 , {a} =
bdtF= ¿ ±
2
∞ T
n=1
[a, a + n1 ) ∈ σ(A1 ) = F1 ,
(a, b) = [a, b) − {a} = (a, b) ∈ σ(A1 ) = F1 ,
A ⊂ F , bd F = σ(A ) ⊂ F . À ^ aE¿ ³ Ý8±W σ(A ) = σ(A ). tiaE¾-W8 GvÊ A = {(−∞, x)| x ∈ N } !®<$ σ O σ(A ) @8«rs 0!F$F»¼½¤SÅ]8@bdTtrs0!F$F» (¼ 88©88Á¼Â©8 2
1
2
2
1
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2
1
}ÁG©Â¼ σ )O ½@¤8+C rÊ@sÌ0j! FØ$a¼$]ÐÛ+=$¼Ð]=Ò©\]7Ò´\¼6]´I$F1´»]¼8½! ¤} $G ]σ8ÆO! @8Ars0!F$©]C@Ê@ä dW8nG σ O @8Ars0!F$vÊ8¼]S©]õ= ,N$ Borel '½!; $!F]^´C ]´^-´S´_`´ä - (±jkl3- ) @ O W8öÊ8¼O ]S©} ]$©õ=,N$ Borel '½!; $!F]^!B<$ σ O ¾ ** Borel 8n! σ(A ) r0 } Borel C ¿ J8@Ê@Ì A = O {(−∞,À x)| x ∈ N³ } \j Øa¼]©$=I¥©O 8n! Ê σ(A ) ZrG Borel @C ^H¿ ä Ý8 ±W= σ(A ) t\ Borel C ɪ^ 2.1.1, t; 0jkl3-v@$= IÃ[ª-= x| 2.1.2 j Øa$eK 3 ë σ O ¯h8Ò\=Ä Borel O B : O (1) Ê8>(F»¼½¤B<$©!®<$ σ Û O (2) Ê@¥]© {(−∞, x)| x ∈ N } !®<$ σ Û O (3) Ê8>(¼]S©]B<$©!®<$$ σ C O B G5+5,5-?FÅÃ5[5$Æ58 =z5j 5Ø5a5$ Borel O ?5õ B . B Borel @$]^** Borel _]8 Ä** Borel ]8 B ∈ B ¸¹ B \ Borel ]C jkl3-v@W8efG£¤ Ω 8w § 0 σ O F, mo (Ω, F) t**= I_£¤C §2.1.4 ÇÈ G 1.7 Év@8 Ö Ê äË , f (A) +, P (A), Ì § Ë , f (A) 4 n $ÍgÎsÎpÏÌ+, P (A), bd¸@+, P (A) $ÐÑGCcè\8c*0 åovò@ó “Î|s}ÎÓpÔ Ï ”, ÒY
;
+, P (|f (A)ï−Ù P (A)| ≥ ε) 4 n $Íg Îsΰs CÌ\8+ÕÖ0=I+R×Ø$ C Ú \*0ÛÜHI ïÙ 8+ÝMÞa0%&'$ßC +, P (A) \= ë ÐÑG8c! } t } p 34awQ= ëÓÔ Cc ¨ G tà s@e ÑÓÔ +,C / Ω \=I¡¢£¤8Ë@GQ´a´ÝO w § 0´=´I´ σ O F, Ì}\t F0 I_£¤ (Ω, F). Ê@ÌD ô σ FÓ @$]^vò@ó 8! tD0 Ï[ = v@$]^ ( Ó ) /u+,C § +,5\ 9 EÓ ´®´N¯´$=I/á8·m oQMNì[ j^Fn
T 8eK [ \ZMN$= () 8 Ï Ð Ñ E, ÒF P (E) ≥ 0; .8+F P (Ω) = 1, b* Ω \Z Û 5 8ef {E , n ∈ N } \=6¿¿
g$ 8motF 38
1
1
1
1
1
1
n
n
n
n
P
∞ S
n=1
En
=
∞ P
n=1
P (En ).
a8bcdef 39 55ô5H 59 ZMN55$59 [ Ó Ó ÇÈ?ò@ó:â¯58:ß5¯S565 | ¯C ¨ G$ ø5ù5\= “\D5D5[MN5H [ t5¼´0j^F ” 55¶58n¼5/059 Cn45Ó i5j5k5l535$HIxO yã@H=8b* _`-$´s8+M/NH [ $ P t\/ uG σ F a$=Iß$_`Cö*09!FHIÒN&8ös
¡C ä 8G´´´$ 5/9 [ Ó J´K´8+´I´´ E Ò Ï ´0´=´I/á 0 ≤ P (E) ≤ 1. ! } P \/uG σ O F a$å̽¤ [0, 1] $=I]^l3 (Q$ ] ká\] ^8± E ∈ F). sHI]^l3 P üFì¯Q^F * & ̶µ8zs$ 59 [ Óæ Içè= 1 éêë Û 2 ìíë Û 3 îïîðë C QÒ\]^l3 P $¯QC[sñQ U § P $Q 8 9 ¯Q= §2.1
◦ ◦ ◦
4◦ P (Φ) = 0.
b*ef bd
E1 = E2 = · · · = Φ,
mo ] F
Ei ∩ Ej = Φ,
i 6= j,
\=6¿¿
g$ 8+òvÊ@¯Q
{En , n ∈ N }
∞ [
P (Φ) = P
En
!
=
∞ X
P (En ) =
ä HIó { DFG P (Φ) = 0 iMN<ôC 5 õöîðë = e f {E ,k = 1, 2, · · · , n} \ n=1
◦
n=1
k
P
ja8D[G¯Q 6 îøë = ef E ◦
3◦
1
8[
n S
Ek
3◦
=
k=1
n P
W
∞ X
n
I¿¿
g÷ 8mo
P (Ek ).
k=1
En+1 = En+2 = · · · = Φ
∈ F, E2 ∈ F,
"
P (Φ),
n=1
E1 ⊃ E2 ,
ÕF
±C
ù } Ê@FÎ | ¯W
P (E1 − E2 ) = P (E1 ) − P (E2 ).
b*di
E1 E2 = E 2 ,
$
E1 E2 ∪ E1 E2c = E1 ,
P (E1 ) = P (E1 E2 ) + P (E1 E2c ) = P (E2 ) + P (E1 − E2 ).
7◦
úûë = ef
E1 ∈ F, E2 ∈ F,
dvÊ@ü¯ô;C 6◦
8[
E1 ⊃ E2 ,
P (E1 ) ≥ P (E2 ).
8◦ P (E c ) = 1 − P (E).
G¯Q
"
E1 = Ω, E2 = E
±;C
ÕF
40 9◦
ðý x| = e f {E! , k = 1, 2, · · · , n} \Ð2 n I 8mo k
n [
P
k=1
Ek
þ È8ef
=
k=1
X
+
1≤i<j
n = 2,
n X
P (Ek ) −
X
P (Ei Ej )
1≤i<j≤n
P (Ei Ej Ek ) + · · · + (−1)n−1 P (E1 E2 · · · En ).
(2.1.1)
F
ÿñ S @HIª-C @ n = 2, yW E E , E E , E E ¿¿
g8"
P (E1 ∪ E2 ) = P (E1 ) + P (E2 ) − P (E1 E2 ). 1
2
c 2
1
c 1
2
E1 ∪ E2 = E1 E2 ∪ E1 E2c ∪ E1c E2 ,
ù }
E1 E2 ∪ E1 E2c = E1 , E1 E2 ∪ E1c E2 = E2 , P (E1 ∪ E2 ) = P (E1 E2 ) + P (E1 E2c ) + P (E1c E2 )
= {P (E1 E2 ) + P (E1 E2c )} + {P (E1 E2 ) + P (E1c E2 )} − P (E1 E2 )
à l/@
= P (E1 ) + P (E2 ) − P (E1 E2 ).
i ª´-´ô´8+@ ´ n = 2 i÷ª-W n=k
P
k+1 [
Ej = P
n = k+1
k [
i´8+¹
A=
k S
Ej , B = Ek+1 ,
j=1
Ej + P (Ek+1 ) − P
k [
Ej ∩ Ek+1 ,
i ÷ª-Öv@8& û ±W n = k + 1 iª-T<ôC 10 /ë = e´f {E , n ∈ N } \´a /÷´´ /ç/6´8± E ⊂ E 1, 2, · · · , ÕF !
Éz
j=1
n=k
j=1
◦
n
n
∞ [
P
"F
n=1
þ
n=1
∞ [
n=1
=
=P
m [
An
En
lim P
m→∞
/ë = e´f 1, 2, · · · , ÕF
n=1
!
Õ A , A , · · · ¿¿
g8 Ì\vÊ@¯Q 3 S¯Q 5 W
∞ [
An
n=1
P
!
=
∞ X
1
◦
P (An ) = lim
n=1
2
m→∞
m X
◦
P (An )
n=1
= lim P (Em ). m→∞
{En , n ∈ N }
n=
n→∞
n=1
!
n+1 ,
= lim P (En ).
2 A1 = E1 , An = En En−1 , n = 2, 3, · · · , ∞ m S S An = En Em = An , m = 1, 2, · · ·.
P
11◦
En
n=1
S< ∞
j=1
Ì´\ Ê
∞ T
n=1
En
\´K/÷´´ /ç/6´8± = lim P (En ). n→∞
En ⊃ En+1 , n =
a8bcdef Ê@Ìdi {E , n ∈ N } \a ÷ ç688òvÊ@K ¯S Õ;Wa ¯C 12 îðë = ef {E , n ∈ N} \=6 8ÕF §2.1
c n
◦
n
∞ S
P
En
≤
De Morgan
ñ
P (En ).
) Ê | ñ/&Sÿñ8 S | ¯= ; ÌFÎI ÷. S P n=1 m
É[
∞ P
41
P
n=1 m
En
≤
P (En ).
K ¯±; 12 . H5¡5=5s58 5 & } Êm ¥ ¥ ù5ß/÷÷ 559 9 ¯Q U § 0õ5* “+5, ” ùP5F ÷ùFQ ¯QC£ù 8£ám { ùß/÷÷ ¯Q\ “+, ” ÷m6¢÷¯QCÆb } d <</u÷ = xy 2.1.4 lF_£¤ (Ω, F), */uG F a÷]^l3 P *+,_`8 efQPFeK 59 ¯Q= Ï Ð Ñ E, ÒF P (E) ≥ 0; 1 éêë 8 ± 2 ìíë 8 ± P (Ω) = 1; 3 îïîðë 8 ±ef {E , n∈N } \=6¿¿
g÷ 8motF S P n=1
n=1
◦
m→∞
◦
◦
◦
n
P
∞
En
=
∞
P (En ).
"ü } ôea÷¾-ªf<</&= x| 2.1.3 +,_` P PFaE¯Q 1 7 12 . n=1
n=1
◦
◦
ô/u0+,_` P ÷_£¤ (Ω, F) **+,£¤8+?* (Ω, F, P ). ¸ §2.1.5 ÇÈ *0HI0+,£¤8w § +,£¤÷=ì¥C @28Ð Ñ +,£¤Ò´F 5 I´[/=¡´¢£´¤ Ω, σ O F S/uG a÷+,_` P . ¸ 2.1.2 (Bernoulli ) l Ω \=I¡¢£¤8 A \ Ω ÷=I:£ { ¥ ]8 F = {Ω, Φ, A, A }, p *°Ì 1 ÷ Ú 38+? q = 1 − p, [ = 1, P (Φ) = 0. ä ed/u÷]P^(A)l=3 p,P MP N(A+) ,= _q, `P÷(Ω) ¯Q 1 7 3 , $ (Ω, F, P ) t\= I+,£¤8+** Bernoulli . G==.÷¦~v@8 Ω = { Ú Ý8 ¾ Ý }, A = { Ú Ý }, ef *§÷8ÕF p = , ef
§8Õ p 6= . c
c
◦
1 2
◦
1 2
¸ 2.1.3 (õö ÇÈ ) l¡¢£¤ Ω = {ω , ω , · · · , ω } *FÎ]8 σ O F * Ω ÷ùF¥]ùB<÷© (F @Ï ÍF 2 I¥] ). l p , p , · · · , p * n I:âj38F p + p + · · · + p = 1. Ω ÷=I¥] E, [ 42
1
2
n
n
1
2
1
2
n
n
X
P (E) =
pj .
(2.1.2)
j: ωj ∈E
TË~ S P M NË+Ë,Ë_Ë` ÷˯ Q 1 7 3 , þ ù } P \Ë=ËÏIË+Ë,Ë_Ë`Ë8+ò õ ö Ç È . È 8e f I {ω }, Ò (Ω, F, P ) \ = I + , £ ¤ 8+* * [ P ({ω }) = , m5o (Ω,ê F, P ) t5\5=5I!ÇÈ!! . =5F5Î5+5,5£5¤ Âà +,£¤÷½ÈtGÌ I6¢ ÷+,"Z¯óC ¸ 2.1.4 (#$ÇÈ ) l¡¢£¤ Ω = {ω , ω , · · ·} *6]8£ σ O F * Ω ÷ù5F5¥5]ùB5<÷5©5C l p , p , · · · *5=6:â5j5358 p +p +· · · = 1. Ï Ω ÷=I¥] E, % (2.1.2) { /u P (E), Õ~ S P \=I+,_`8 Ì \ (Ω, F, P ) \=I+,£¤8+**$ÇÈ . ¸ 2.1.5 ('()/Ç/È* ) l´¡´¢´£´¤ Ω +´j/ ´Ø´a/÷/P´F Ú Lebesgue _`÷I Borel ]8+ σ O F + Ω ÷ùF Borel ¥]ùB<÷©C Ï I E ∈ F, [ P (E) = , S P \=I, -v. /L(E) S L(Ω) Çȸ¹]^ E Ω ÷ Lebesgue _`Cc
T~ 0 Ì1 (Ω, F, P ) 123, -450678 29:;,<>=8÷, -45?A@ BCDEF n 9:;, -45? þGH0IJ Ω 8KL5 (0, 1), MN σ O F 8L5 (0, 1) =QPRS Borel T U RVWP C 0XYZ@ B[ P \] L, 7 Lebesgue ./? ^_ 2.1 1. ` P (A) = P (B) = 1/2, acb P (AB) = P (A B ). 2. ` A, B, C dce 3 fcgchcijacbck (1) AB ∪ BC ∪ AC ⊃ ABC; (2) AB ∪ BC ∪ AC ⊂ A ∪ B ∪ C. 3. ` a, b dclcmcijncocp a ∨ b qcr max{a, b}. scacbcijtcucvcwcfxgxh A y B, zc{ P (A) ∨ P (B) ≤ P (A ∪ B) ≤ 2[P (A) ∨ P (B)]. 4. acbctcucv n fcgch A , · · · , A, zc{ T P ◦
◦
j
1 n
j
1
1
2
2
1
2
L(E) L(Ω)
c
1
n
n
n
P
≥
Ak
P (Ak ) − n + 1.
cd ucv n fcgchci A = S A . sc| A qcrcd n fc}c~ccccgchccc 6. ` A B dcec
cgchcijsccxx{xcgxh X, (X ∪ A) ∪ (X ∪ A ) = B. 7. ` A , A , · · · , A dcgchcicgch B qcrcgch A , A , · · · , A c { m fcgchccc acbck
5.
`
c
k=1
A 1 , · · · , An
n
k=1
i
i=1
c
1
2
n
m
c c
1
2
n
>Q
§2.2
43 P
n−m
`
P (Bm ) = Sk =
P
`
P (lim inf An ) ≤ lim inf P (An ),
dcgchcPijacb
n→∞
A 1 , A2 , · · · , A n
9.
`
O
d
4
<
n→∞
i=1
xx¡x¢xx£x¤xi
P (Ai ) − 2
P
B = σ(O) = σ(J ).
n→∞
n→∞
P (Ai1 Ai2 ) +
1≤i1
P (Ai1 Ai2 Ai3 ) + · · · + (−2)n−1 P (A1 A2 · · · An );
d x{x¥x¦x§x¡x¨x©x£ª¤x«axbªk
1≤i1
J
lim sup P (An ) ≤ P (lim sup An ).
P
n
P (A1 4A2 4 · · · 4An ) =
10.
P (Ai1 Ai2 · · · Aik ).
dcgchcccijacbck
1≤i1
{An , n ∈ N }
8.
m (−1)k Cm+k Sm+k ,
k=0
<
Borel
¬
®¯°¯±¯²¯³¯´¯µ¯¶¯·¯¸º¹¯» ¯ ¼½ , -./ P 12 ¾¿À 0@ BÁÂÃÄ PÅÆÇ<È:;Ç<ÉÊ ? ËÌ>ÍQÎÏÐÑÒ ÅÆÇ<>= ÑÓÔ 45 Ω = {ω , ω , · · · , ω } ]SÕ U Ñ M!N σ O F ] Ω P!R!S!T U R!V!W!P C (F =×Ö!S 2 3!T U ), Ø!Ù!3 {ω }, Ú!S P ({ω }) = . ËÌ [ÛÜ 2ÝÞÊ Ñß>à ÇáÉÊ ÁÂâã Päå Ä Ó ¿ ? æ 2.2.1 çèéê2ëìíPîT 2n + 1 ï Ñ×ðñ êòPóô Äõö ôPÇ á ? ÷øùú 23ÅÆÇ<ÉÊ Ñûú ¼½ óô Äõö ôPMN E üýØþMN Ñ @ B ÓÔ 3 ? E PØÿ¿ B E êòPóô Äõö ôPMN Ñ õ Öé Ñ R B EZ ú ê ï êòP ö ô Äõ óôPMN ? õ îT ú ìíP Ñ R B P (E) = P (E ), S §2.2
1
2
n
n
j
1 n
j
c
c
c
2P (E) = P (E) + P (E c ) = P (Ω) = 1,
1 2
ù ØþMNP Á Ê ã Ñú Çá>= Î ½ P ? 3ÞT ? æ 2.2.2 2n 3 n 3!"#$ Ñ Ù# è ?%& ñÌ"'"( H") W"* + Ñ,ð S #-è !./PÇá ? ?21 ø Ω Z ú 2n 300!P0*04 +05 P 0 B E 0 !0 S 0 0 # ! è 0 0 ! 0 . ! / ! P ! M N U06 Ñ R B |Ω| = (2n)!. û!ú |E| !70809 ð0:!Ñ2; ]!ý =×P0<0=?>A@B0C Ñ2D0EF G G S: 3#P 3è !./ IÑ HDG 3è.J ÄK ÑILL ? ûú Ø!þMN Ñ2N 7 ÏÐ |E | = 2 n!, ; 6!Z S P (E ) = = E 0 0M0#0-!è!0 Ú 0 . / ¼½ ÇáP¿À 8 , 7 :
c
c
P (E) =
n
c
◦
P (E) = 1 − P (E c ) = 1 −
1 (2n−1)!!
.
.
2n n! (2n)!
1 (2n−1)!! .
O PQ RST æ 2.2.3 UWV>=QS n − 1 3YXWZÈ 1 3[Z Ñ Ùï\>= '( \ò 1 3Z Ñ] ^_ 1 3YXWZ Ñ I6 Ö` k ïa` ? ,ðb k ïa`c\òPZ ú XWZPÇá ? " B E " b k ï"a"`"c\òP"Z ú XdZPMN ?1 ø Ω Z ú k ï\ @e Pf J Ñ 7 Ï |Ω| = n . ûú |E | !789 ð : ÑËÌ G E . ZP R S b k ïa`c\òPZ ú [ZPMN ? õ UV = 7 ÑÏ E * e Ö g S 1 3Ñ [ ^ _ Z Ò Ñ ú Ñ ú j Ñ õ ZBk *h çïÑin\oò p PÚ XWZ ú ô ù\Óc b g \òYXWÑ Z BR Ñ E lm k − 1 ï\PÚ XZ gS k ïq\[Z R |E | = (n − 1) , \r = 1− , P (E ) = 1 − P (E ) = 1 − 1− . P (E ) = Is PÞÊ DE Ø n F <tu ? ^YQw Hx \ n 3 Ñxðù n 3 æ 2.2.4 \ 0, 1, · · · , 9 ù 10 3> v W = ! Pyz @ B i 10 {| PÇá ? B E ù n 3Pyz @ B i 10 {|PMN Ñ 1 ø S 1 ≤ n ≤ 10. ÑËÌ g \*3v Ñ}~} v ú 0 c @ B i 10 {| Ñ R B n=1c P (E ) = . Ñ R!S00v00i!\!ò Ñ! Ì P0y0z0* E @ i 10 {0| Ñ R B P (E ) = 1. n = 10 c Ò ý<t s ÑËÌ B A Ñ ½ B R \ ò P n 3v = S 0 PMN R\òP n 3v =
S 0B ûú n 3 Pyz @ B i 10 { | PMN ?1 ø S 44
k
k
c k
k
c k
c k
c k
k−1
(n−1)k−1 nk
c k
1 k−1 n
1 n
1 k−1 n
1 n
c k
k
n
1
1 10
10
n
An Bn = Φ, An ∪ Bn = En ,
N 7 ð:
M
P (An ),
n
R
P (En ) = P (An ) + P (Bn ). n |Ω| = C10 , |An | = C9n−1 , C9n−1 n . C10
s ôÒ ð P (B ).Ñ ú 0, ; 66 ≤5n* ≤E 9 E c \ò RÑ \yòzP q n@ 3i 10v>=W{* | Ò | 0 È 5 Pý 8 3v>= x \ Ñ; P (An ) =
n
P (En ) = P (An ) + P (Bn ) =
GH ÑËÌ S
Ò
R B
E S Ñ} B lm c Ñ ! ? | 5 Ñ ý n − 1 3v @ 6 |B | = C , n
n
C9n−1 + C8n−1 , n C10
C98 +C88 9 C10
n−1 8
6 ≤ n ≤ 9.
= = 1. Ñ Ñ Ñ]~H \ò*3 E 2≤n≤5c B lm 5* i \ ò ? Ò 5 i\òP<t s Ñ ý n − 1 3]P\ ã S C Ñ R B 0 : P (E9 ) =
9+1 10
n
|Bn | = C8n−1 − C4n−1 ,
n−1 4
P (En ) = P (An ) + P (Bn ) =
C9n−1 + C8n−1 − C4n−1 , n C10
2 ≤ n ≤ 5.
>Q 45 æ 2.2.5 ( _ ) [ m 3!PZ L @eH^_ n 3!PT Ñ , ð ò % PÇá ? m > n. 0 [ 0 !ò % P!M!0 Ï Ω *04 @0e P ^ ã0 W Ñ S |Ω| = n . N ! ] E. 7 ûú |E| !7 ð : ? ËÌ ð P (E ). B A b k T ú PMN Ñ k = 1, 2, · · · , n. 7 Ï E = S A . ËÌ ¼½ Çá ã P (E ) = P S A . õ MN A · · · A P ú P Ñ R B MN 0 Z0Ú 0¡ý0 n − i 30!T 0 0 ? b WL j , · · · , j 0!T!Ú @ e ¿P¢£ Ï = §2.2
m
c
c
k
n
k
k=1
n
c
k
j1
k=1
1
i
B¤¥ _ Çá ã Ѧ:
P (Aj1 · · · Aji ) =
(n−i)m nm
= 1−
!
i m n
.
m m 1 2 = Cn1 1 − − Cn2 1 − n n k=1 m n−1 m X n−1 i n−2 n−1 i−1 1 + · · · + (−1) Cn 1− = (−1) Cn 1 − . n n i=1 c
P (E ) = P
n [
Ak
R B ò % PÇá]
S
Pn−1
i m n
s ô 3:;Ç<ÉÊ ÑÌ Ú ú é §ÉÊP¨© ? ËÌ Í ÎÏÐÑÒ :;Ç< = ÑÓÔ"ª Ω ú ç3«S Lebesgue ó¬P U Ñ MN σ O F ] Ω PRS Borel T U RVWP C ? ]~ ØÙ3 E ∈ F, Ú Borel P (E) = 1 − P (E c ) =
æ
i=0
P (E) =
(−1)i Cn1 1 −
L(E) . L(Ω)
.
®¯ _° ) ±ôÑ ²S*³ ª J,] ð a P±´8µ Ѷ ±ô '? ( éê*38·] l P¸Y¹Q<º»¼ ý>= l < a. º»¼ü8µ.½PÇá ¾¿ ¸À¹ <º»¼ ú *3ÁÂÃÄ ÒÀÅ PÆÇ= ? ]È õ ýü8µ.½ PÇá ÑËÌEÉ ½ *ÝÊË ? [Ì SP¸À¹ <º» Ó P¸À¹ <º»¼ Ñ ÿ ¼ ÿÑ ] [ “ ͼ ”, Î \ * 3 ÌÒ W*38 ] “ ÏWù ¼ ”. £Ðº»? ¼
SÑ · ] l PY¹ ?% ÒY¶ ± ô éê 3YQ¹ <º»¼ F G B A È B “ ÍW¼ ” È “ ÏW¼ ” ü8µ.½PMN ? õ úÑ A ∪ B Ñ r AB “ ÍW¼ ” È “ ÏW¼ ” Úü8µ.½ P YQ¹ Ñ<¾º¿ » ¼ ü8úY µ. ½ P M N Ó Ç= Ñ R B AB LÔ õ 3 “¸Y¹ ” P Ö8· (. } õ * M N ¡ Y ¸ ¹ ÕÖ ] l P§ ) ü8µ.½PMN ? 7 Ï P (A) = P (B), Wb *×Þ 1.6.4 P Ï P (AB) = 2l/πa, ËÌ ð P (A ∪ B). 2.2.6 (
ji
46
B
d
Y¹WØ¡8µPÙÚJÛ ? 7 Ï S n
ao Ω= d|0≤d≤ , A∪B = 2
R B
P (A ∪ B) =
RST
OPQ
l d|0≤d≤ 2
.
L(A ∪ B) l πl = = . L(Ω) a πa
ÇáP ã Ï BR ð: P (A ∪ B) = P (A) + P (B) − P (AB) = 2P (A) − P (AB), P (A) =
P (A ∪ B) + P (AB) = 2
1 2 πl
+l . πa
ùÐ Ê = ËÌ ¡Çá ã P* SÜPÝ ½ â ? ù \*3 â ôÞ \ ß ËÌ Çá P Á Ê âã ú äå Äà P Ñ Ý } ¾¿ \ Á Ê Üá =Wâzã Îä ? ù!Ð Ê!P0f0 =×S0*030å : ¾¿ P H â Ñæ¦ P (A) P F T0ç0è ú ¸?¹×<0º0»¼ PÖ?«é XÖ Y ? Ò r Ò é§ÉÊ>= Ñ §Ñ«üú8ì µ.½CPD Çá>=QP F T Â2lð ê ú@ ñ B E W Ñ ú §¤ PËé Ì éê*Ñë ôPõ Ç@ =Bc ÛÜ êS ö Pfíïî ? P Ø !`òóu * Ý Ç=÷ æ 2.2.7 (®¯ _° ) Ò ±ô²S*³ ª J] a Pø±8µÈ*³ ª J] Ñú¶ '( H éê"* ÕÖ Ñ , ð b Pù88µ ± ô ] l P§ § ü8µ.½PÇ Ñ á ý>=
p
B E 0 0§!ü!ç!¾080µ0.0½!P!M!N Ñ F G B A È B 0 0§!ü!ç!¾0ø0±08 0 µ0.0½0û0§!ü!ç!¾0ù08080µ0.0½!P!M!N Ñ õ ú Z S0§ü080µ0.½!PM!N E = A ∪ B.
Wb * × Þ 1.6.4 P Ï P (A) = , P (B) = . Ë!Ì ð ò P (AB). 1 ø!Ñ M!N AB 0 0§0ü!ü!ç!¾0ø0±080µ0.0½0ý!ü!ç!¾ ù88µ.½ Ñ ? B B ρ È δ F G § P>= üø±8 µ PÙÚJ Û È § üù88 !µõ P0ú Ù0Z Ú0J0Û θ 0 0! § ü0ø0±080! µ P0þ0ÿ (\0r0! § ü0ù08080! µ P0þ0! ÿ ] − θ). l
(a + b)2 − πab.
2l πa
π 2
S
Ω=
õ ú
2l πb
AB =
(ρ, δ, θ) | 0 ≤ ρ ≤
a b π , 0≤δ≤ , 0≤θ≤ , 2 2 2
,
l l (ρ, δ, θ) | (ρ, δ, θ) ∈ Ω, ρ ≤ sin θ, δ ≤ cos θ . 2 2 L(Ω) = 18 πab,
L(AB) =
Z
π 2
0
dθ
Z
l 2
0
cos θ
dδ
Z
l 2
0
sin θ
dρ =
l2 4
Z
π 2
0
sin θ cos θdθ =
l2 . 8
>Q
§2.2
R B
47
P (AB) =
L(AB) l2 = . L(Ω) πab
Çá ãE Ï P (E) = P (A ∪ B) = P (A) + P (B) − P (AB) = . I s w H « Ñ Ë Ì Ñ u é § É Ê ` M = P ! ô ¡ Å Æ
Ç P ØÉÊ ËÌ [ ¡ ãE P89 É ½ æ 2.2.8 ( _ ) ¼ Ñ M S n Ñ ì F G S 1, 2, · · · , n. %
Ò .0P !0P ¼P 0. Ñæ ÿ] !Ì0F G
j W
ò % “ Ø ”. , ð ò % 1 3 ØPÇá ò Ñ# $ ]S0* ¼ ú r s %
^ ! 0 Ø!ÿ!¿0 ! " v &
' ( ) P ; ¤ gUo6 ÑG Î* ¼P ^ !*() Ω Î* ¼PRS!P ^ !()P S |Ω| = n!. A ò % 1 3 ØP+N XY A Z ú Øò % P+N [ b ¼ ^ Òb j ! ÿ] “Ø ” ^ ! -,. Ñ-/0 |A | N 7 ð ò Ñxû j +] !N ø ð; : ] A Î* PRS ¼Ú! “Ø ” ^ ! Ñ ù ^ ã P ! 7 ËÌ H ú 89 G A . ^ !P*+N Ñ XY A Z Î B Î* * ¼ P b j ¼ Ø * 1 S** ¼Ø ^ ! Ñ S A = S B . ËÌE ½ ÇáP ã*2* ð 2l(a+b)−l2 πab
c 1
1
c 1
c 1
1
j
1
n
1
j
j=1
P(
n S
Bj ).
¾"¿ ã323 P "
ð àdD"E ØTRSPó"{" m ( 1 ≤ m ≤ n ) È 1 ≤ j < j < · · · < j ≤ n, ò3+N B PÇá + N"" "Î"* P b 1 ≤ j < j < ··· < j ≤ n ¼ 3 F 4 “Ø" ” ^ ! Ѧ"F34 ^ Ò"b Ñ ¤ c ý n − m ¼ Ò ý P n − m 1 ≤ j < j < · · · < j ≤ n ! 3
!0 x ¿ ^ ! Ñ R | T B | L õ ý0 n − m ¼!P!R!S0!0!P ^ ã 65 Ñ j=1
1
2
(2.1,1)
m
m
ji
i=1
1
1
¦ S
|
2
m T
i=1
2
m
m
m
\r Ï
ji
i=1
Bji | = (n − m)!,
P
m \
B ji
!
ùÓ * ú Ñ Ç áP ã2 ¦ð:
i=1
P (A1 ) = P
n [
j=1
Bj =
=
(n − m)! . n!
n X
m=1
(−1)m−1 Cnm
(n − m)! n!
RST
OPQ
48 =
]~HÏÐ
n X
(−1)m−1
¼Ú
S “Ø m=1
n
1 1 1 1 = 1 − + − · · · + (−1)n−1 . m! 2! 3! n! ”
^ !PÇá] 1 2!
1 3!
1 + · · · + (−1)n n! .
s *3ÞÊ ú
ØÉÊP¨©ÈÝ ½ æ 2.2.9 ( _° ) E7 n 38 9Û ÏÑ 3è F4Ò Û Ï l Û Ï? _:; ,ð s : ; < = j I Ñ ' ( > 8 ÿÈ ;A M +NPÇ : : ; Ï ? Ï ? Û Û á (1) çS k @ Ø (2) S m@ Ø : ; ½ E Ï ? Ñ S m @ Û Ï ½ Û ç S k@ Ø P + N A ? Ø :; P+N Ò Ê ËÌ>ÍQÎð ò A PÇá Ò +!N E c Ñ S k @ Û Ï Ø0 ^ ! Ñ ý0 n − k @ Û Ï !Ø!ò % ( l0m Ú ?B :; ). ð ò P (E ), Ë!Ì D 0 !ç 7 2 P n − k @ Û Ï !Ø!ò % P +!N ] õ ? Ø : ; P k @ Û Ï S C C ã Ñ R 0 e ð0: |D |, X!Y!Z S |E | = C |D |. E ð ò |D |. R D û!ú |D | !70809 ð0!: Ñ R !Ë!Ì D \ P (D ) . D 0! ç 7 2 P n − k @ Û Ï Û Ï !Ñ Ø!ò % F P½ +!N Ñ R D ! E0 !ûÑÏý0 k @ Û Û Ï!Ï Ñ r0g D00G!ù 7 2^ P n−k @ Ê P f n−k @ Ú
S “Ø ” ! P (A1 ) = 1 − P (A1 ) =
−
k
m
1
k
k
k
k n
k
k n
k
k
k
k
k
k
k
PÇá]
P (Dk ) =
1 1 1 − + · · · + (−1)n−k . 2! 3! (n − k)!
â ô ÑcÒ gØ ù7 2 P n − k @ Û ÏG ´ G P<t s ÑcËÌ % ÅÆÇ Î * P P (D ) ]
k
H þ - Ѧ: ¡
P (Dk ) =
|Dk | = (n − k)!P (Dk ) = (n − k)!
ù
õ
P â ã å :ËÌ ¾¿ |E | = C |D |, R
|Dk | . (n − k)!
1 1 1 − + · · · + (−1)n−k 2! 3! (n − k)!
.
|Dk | k
k n
k
|Ek | C k |Dk | (n − k)! P (Ek ) = = n = Cnk n! n! n! =
n−k n−k 1 X 1 1 X 1 (−1)j = (−1)j . k! j=2 j! k! j=0 j!
1 1 1 − + · · · + (−1)n−k 2! 3! (n − k)!
>Q SÜP úÑ ËÌÒ JI n → ∞, :K ÕÇá] . Ñ õ A = S E , ~ +N E , E , · · · , E ! ½ Ñ R þ Ï Ù jú §2.2
49
1 ek!
n
k
m
m
m+1
n
k=m
P (Am ) =
n X
P (Ek ) =
n−k n n−k n X X X 1 X 1 1 (−1)j = (−1)j . k! j=0 j! k!j! j=0
\ * âLM NPOPQ (Ö 52 ) Wx ¿ \ò 13 Q , k ØR K-Q PÇá A \òP 13 Q ã çS Uk6 ØÑ R K-Q P+N 1 ø Ω Z ú \ \ 13 QPRS! \ P R |Ω| = C . Ñ Ñ õ ú g o \ ý 52 − 8 = 44 A lm c 4 Ø R K-Q Ú i \ ò Ñ
æ
k=m
k=m
k=m
ð ý çS S W x 52 Q } +N Q Wx \ 5 Q R 2.2.10
k
13 52
4
5 |A4 | = C44 ,
P (A4 ) =
5 C44 13 . C52
Ñ | S k ØR K-Q i\ò ÑH e c l m S j R T!P 8 K U 8 Q i \!ò Ñ ý 0 ≤ j ≤ 4 − k. Ë!Ì ½ B 0 !S j RTP8 K U8 Q i \òP+V Ñ XYZW A ⊂ S B . ùÓ * Ñ È Ï W 0 ≤ k ≤ 3,
} +N
Ak
j
4−k
k
j
j=0
Ak = A k
4−k S
Bj =
4−k S
Ak Bj .
7 Ï XYZ +V !½ Ñ\[Y ÇᬠZ ¿À j=0
Ë ] ð T ZÑ\[8
P (Ak ) =
4−k P
j=0
5◦ ,
¦ W Õ ¿ Ï
P (Ak Bj ) .
Ò + V A B c Ñ W k Ø0 R K-Q i^!ò Ñ H W Î0 j R l0]m ~HE Ñ K U8 Q i^ò \ý Z 44 Q ^ ò 13 − 2k − j j=0
|Ak Bj |.
k
ô Z ¦:
j
j 13−2k−j |Ak Bj | = C4k C4−k 2j C44 ,
P (Ak ) =
4−k X
P (Ak Bj ) =
j=0
=
4−k X j=0
4−k X j=0
j 13−2k−j C4k C4−k 2j C44 13 C52
13−2k−j 4! 2j C44 , 13 k!j!(4 − k − j)! C52
k = 0, 1, 2, 3.
W Ñ ú 4 RT Z Q Fabc ^ d KW f Z ;_ `W Ü Q( k e
RZh T ), 8 Z ^ d K U Q( j e R T ) f0ü g ^ d K ê g ^ d Q(W Z 4−k−j eRT ) e i “jkkl ” mnoqZ p
p
13−2k−j C44
x uyz
13 − 2k − j
vQ
j
^woqp<{
|}~ *]*
***** Z p Z u******** Z**** { *** Z m*w r< c ¡¢ £¤ r<¥¦§¨©ª«¬o ¢ ® s¯r<j° j±²³´w{ µ¶ 2.2 1. ·S¸S¹SºS»S¼S½S¾-¿SÀ-Á-Â-ÃÅÄ-Æ-Ç-À-ÈSÉ-Â-Ê-Ë-¼SÌ-Í-Î 2. ÏSÐSÑSÒ 25 ÓSÔSÕSÃ×ÖSØSÙSÚSÛSÜSÝSÞ-ÑS¼ 20 ÓSÔSÕSÎ×ßSÄSà×áSâS¼ 3 ÓSÔSÕSãSÇSäSå æ ØSÙSÚ\çèÛSÜSÝ-¼SÔ-Õ-¼-Ì-ÍSÎ 3. ÉSÓSéSêSëSìSíSîSïSéSðS¸-ÂSÃñçòSàôóSõ-Ñ-¼S¸-öSÑ-íS¼-ÌSÍ-÷ 0.6, øSùS¸SöSÑSíS¼SÌ ÍS÷Sú 0.7, ÄSûSüSýSþS¼SÌSÍSà (1) ÿSÒS¸SÓSéSêSÑSí (2) ¸SÓSéSêSÑSí (3) É ÓSéSêSäSÑSí (4) SÓSéSêSä SÒ-Ñ-í (5) ¸SÓSéSê SÒSÑ-í-Î 4. S¸S¹SºS»S ¼ Sî SÀ n ÂSÃÅÄ S¼ SØ 5 ¼SÌSÍSÎ 5. S Ò Sï-¸SÓ-¼ SÑ SÒ !"-à # 3 $%&S¼ Sä "SÈ '(-Î ßSÄ "Å (1) ØSú k;(2) ã k ¼SÌSÍSÎ 6. S ¸ ) 52 *+,-SÑSÒ .!" n * (n ≥ 4)), Ä / n *SÑ 01SÝSáSÒ 4 $2&S¼ ¼SÌSÍSÎ 7. 3547678797 a 7 ¼ :7;7#7< 7¼ =7>7?7777 ¸ ÓS7Á @A CÎ B7DS7Á @7AS¼ Á E7FG l , l , l º HSú a. Ä ISÁ @AJSÖ #<KL-¼-ÌSÍ-Î 8. ¸S. ß NOSÝ N *Sâ PSRÎ QSÓSâSÚ -Ñ "S¸ *ST èÃ<Ä n (n ≥ N ) ÓSâSÚSâ U V ÂÃÅâ MèP WXS'S¼-Ì-Í-Î 9. SSÌS Í YZ[\Së ] ^_ a, A (a < A), äSÒ
50
1
A A−a (A − a)(A − a − 1) (A − a)(A − a − 1) · · · 21˙ =1+ + + ··· + a A−1 (A − 1)(A − 2) (A − 1)(A − 2) · · · (a + 1)a
2
3
ÒS¸SÓ.` 3 öabS¼cdaeS¸SÓfgcdSöSï.^ëSýhiSÈjD-Îkcda-æ ÑSÒ 2 öKl Í p n"SÆoS¼jDSÃqp 3 ÓSöSÝijDSørSÀS¸S¹S½-¾-à cdast uf¼g!vmSiSÌS È wxjDSÎèøfgcd-öym-ÌSÍ p n"SÆoS¼jDSÃ#ßSÔcdaJfgc dSöSÑSRà S Ó iSÈSÆ ojD-¼SÌ-Í-Ø z 11. {SÑS Ò 1 5 |}S¼ 5 Ó S~à SÑ S "SÈ 3 Ó S~à "SÈ V .èÎ Ä-ûSü-ýSþ ¼SÌSÍSà (1) SÂSÈ |} 1,4,5 ¼ (2) á "SÈS¼ SÒ |} 1,4,5, ø J/X "SÈS¼S Â
SÎ 12. -¸- Ó H-Ò 1 10 |}-¼ 10 K-¼ -Rà -Ñ - !-È 3 -ÃÅÄ SÂS È |} 1,2,3 ¼SÌSÍSRà "S¼ Z-å-à (1) . (2) Ò .èÎ 13. SÀS¸S¹SºS»S ¼ -îSÃ<Ô SÀ t Â-Rà [ È 6 S¼SÌSÍ HSú 0.3? 14. SÑSÒ n . Ó J n Ó Sà ·SáSÒ SÑ b-ë !"SÈ-~à "-ÈS¼ .rSÃ×ßSÄ áSÒ SëSÑ S¼ %&-ä -¼SÌ-Í-Î 15. SÑSÒ a . Ó J b Ó Sà Sö r -¡Ã QSö Q- S¸-Ó-à ¢£¤-¡Ã QS " ÈS¼ .rSà ¥¦§; -óSõ-Ñ S¸-Ó-ö -È (-à ÄSû-ü-ýSþ-¼-Ì-ÍSà (1) ¢ S. È (2) ¢ S.È SÎ 16. É- ÿ -î-Ñ -Ò H-Rà H¨8©ª«¬%&®¯-Ã<Þ-Ñ p-¸-ÿ -î Ò 5 Ó -à 11 Ó Sà 8 Ó ø pSÿ SîSÑS¼ K° ±¯² 10, 8, 6, /SÉSÿ SîSÑ !Sï "SÈS¸S Ó ³SÃÅÄSá %&K-Î 10.
§2.3
´¶µ
51
{SÑSÒ|} 1 n ¼ n Ó·SØHS¼SøSÑS¸SÓS¸SÓ!- à !-·"SÈSÎ~p k ÓS " ÈS¼S ¼}¹-ãSÇ k, yº»SÚ “¼½ ”. ßSÄ »SÚS¸S “¼V ½ ” ¼SÌSÍSÎ 18. ¸¿ ìÀr ¼ ±Á é-ð 3 Â-ÃRÂ-Â-é-ðÃ-Ñ ±Á-¼-Ì-Í-÷-ú 0.8, ø Ã-Ñ-ÍÄ-ÂÅ ¾ 0.1.öÄSûSüSïSýSþS¼SÌSÍSà (1) 3 ÂSäS ÒSÃ Ñ (2) ¸SÂSÃ Ñ æ (3) ÃSÑ 2 ÂSÎ 19. 18 ÂfgÆS Ç ¼ Brenoulli ßS È ÑSÃýSþ A S» ÚS¼SÌSÍSäS÷Sú 0.2, Ä ýSþ S» Ú 3 ÂS¼SÌSÍSÎ ÂSÂ-Ñ.±Á-ÃÍÌÎÊSU(-áQ- 20. ÖSöÉÊ¥¦SÃ¡Ë -Ý 6 ÓÊrSá# ÊS ÑS¼S ÌSÍSäS÷-ú 0.7, Ä Ï ÒS¸SÓÊ Ò È-¼SÌ-Í-Î 21. ÒSÉ$ ÐS Ñ ¼ÒÓS Ô ¼Õ þSÃÍS Ö õsÐѯSb É× Î¡ÓÔÎQÓÔU ¸-ÓÕ þ VV à äØÙ>!mKS¼-Ì-Í p-¸×Ìp×SÑr"-û-¸SÓÒÓÔ-¼Õ-þSÃèøÓÔ ¼ SÕ þysÚÐѯ²-Û É-ÓÜÝ r ¼S î (S îS¸£S¤ åSÞ ¼ ), ßSÄß»S ¼Õ þS îSÑ û-à ÃÅù-¸-ÿS î-Ñ-Ò m ÓSÕ þS¼SÌSÍSÎ 22. çò-Á-Ó-ý-þ A, B, C ÒK-¼-Ì-Í p, -É-Éfgá-Á-Ó-ý-þ à»-Ú Î<ßoD p ¼S تSâ Î 23. ãäS å Ê 1891 S æ ¼çèéêëS ì ÃîíS ï Ùð»S àîñSò ¼óôeñSò ¼õ î (AB) ö éSê ö.èM ¼ 5%; ñS ò ¼óôe÷&ñò ¼Sõ î (AB ) öéSê ö.èM ¼ 7.9%; ÷&ñSò ¼ ê ö.èM ¼ 8.9%, ÷&ñòóôe÷&ñSò ¼Sõ î (A B ) óôeñS ò ¼S õ î (A B) öéS öéSê ö.èM ¼ 78.2%, ßøùóôeS õ îS¼ñò ¼%&¨8 ¼ú Î 17.
c
c
c
§2.3
ûýüýþýÿ
c
r ¡ ¢ r (Ω, F, P ), u P (Ω) = 1 {"! u ³#$%& '() r"*+,./ { 0 r213 456 789 r : 3, ; o<=orS>>, ; o?G@F 1 rBAA{BCDE# “ :.G / 3G, ; o<=o ” F ¯ u ./ r s G>G, *G H P+GQ IGJ*³G& # *GK ³ ¥GL*rM&GN * ¯ u { - O §2.3.1 RSTUVWXTYZ[\]^ _ O`ab² ¡¢ { c 2.3.1 13 456 7G89de: 3G, G;Gf
52
¯
A.
B
no¯
no d @¥>
AB = {3, 5}
|AB| 2 = . |A| 3
P (B|A) =
A { p @
J³ K u F ¡¢ iM 0 Ω = {1, 2, · · · , 6} < ³ ¦§|} (2.3.1)
(2.3.1)
¯
P (AB) =
|AB| |Ω|
= 26 ,
P (A) =
(2.3.1)
} d : O * d CD |A| |Ω|
=
3 6
.
P (AB) 2 = . P (A) 3
P (B|A) =
(2.3.2)
O 8 y c 2.3.2 s ³ ¡ 1, 2, · · · , 10 10 ¢£¤¥¦§¨ ¢ d© §, £¤ ¡¥ª@ 3, g >« ¡<¬ f ® y hlij Ω = {1, 2, · · · , 10}, A = {3, 4, · · · , 10}, B = {2, 4, 6, 8, 10}. ¯lOl> ²³dM´ pµ P (B|A). °± (2.3.1) P (B|A) = = = . ¶· _¸¹ |AB| |A|
4 8
1 2
º ²³dM»¼½ µ P (B|A) = = = . ¾¿ÀÁÂÃÄ (2.3.2) ÅÆÇÈÉ ´ÊÊ P (AB) Ë P (A) ÌÍ uÎÏÐ ® P (B|A) ºÑÒÓÔÕÉ Ö× 2.3.1 Ø (Ω, F, P ) ήÙÚÛ A ∈ F, B ∈ F, «Ü P (A) > 0, ÝÞ °±
P (A) =
(2.3.2)
|A| |Ω|
=
8 10
= 45 ,
P (AB) =
P (AB) P (A)
P (B|A) =
2 4
|AB| |Ω|
=
4 10
= 52 .
1 2
P (AB) P (A)
(2.3.3)
ß Îàá:â A Æãºäåæ Û B Æ㺠ÏЮç èéê ¹ÛMÏЮ½ë ÔÕ à®ÙÚ (Ω, F, P ) ¾ º ®ìíÛ éî ½ï ð ® º 3 Ïñò Óó ÛMô ÉMõöÓ ÛM÷ø Óù ´ú´û Ó çMüýþ æÉ Öÿ 2.3.1 (2.3.3) ÔÕº ÏЮï ð ® ºõöÓ Û©÷ø Óù ´ú ´û Ó 3 Ïñò Óó ç É õöÓù ÷ø Ó î Û ý :´ú´û Ó ç ë úÀÀ º ÐÛ A ∈ F, P (A) > 0, Ý {AB , n ∈ N } Ø {B , n ∈ N } Ñ ½ë Ñ úÀÀ º ÐÛ ¶ ® ºÓó 3 ô´ú´û Ó â n
ྠÀ»Ê
n
P P (A),
∞ S
ABn
=
ô (2.3.3)
n=1
∞ P
n=1
◦
P (ABn ).
§2.3
53 P
∞ S
ABn |A
=
∞ P
P (ABn |A).
(2.3.3) ÔÕº ÏЮ½ï ð ´ú´û Ó ç Á Ô (2.3.3) GÔGÕGº P (B|A), B ∈ F º! ëG´GìGÙGÚ ¾ Á®ìíç#"$ÏЮ%&®ìí º & Óó 1 − 12 . èéê Ω, F ºÑ ¹Ûà (2.3.3) Ü:Çȯ ¸ P (A) > 0, ëÎ'(ý)* Î 0. à,+.- º è ±/0 Ü? ÛÏ Ð Ñ¯ ¸ ÑÒ1ç 2 ï ð çkà Þ34Ñ56789:;< Û ÇÈ=Þ4Ñ5> :;º:@ ´Ê Þ (2.3.3) AB Î n=1
n=1
◦
C Ð
A
ù
B
◦
P (AB) = P (A)P (B|A),
(2.3.4)
P (AB) = P (B)P (A|B).
(2.3.5)
ºDEºF ß Ó Û éî ½ èé &
G À Á 9G ¹'HIGÀGÁ ÐG» ÆGãGº:;GºJ MÛ ´GÊKL ÈMNGµO Á Ð ºPQ Û µ þ æºRS:;ºT ³ ÔÉ Öÿ 2.3.2 (UWVWXWYWZ Ö ÿ ) Ø (Ω, F, P ) Î :W; Ù Ú Û {A , k = 1, 2, · · · , n} ⊂ þ[ P ( T A ) > 0, Ý & F. k
n
k
k=1
P
n \
Ak
!
= P (A1 )P (A2 |A1 )P (A3 |A1 A2 ) · · · P (An |A1 A2 · · · An−1 ).
(2.3.6)
]É \^ (2.3.5) Ä_`³ô´ç Á ÔG ¹'HI O Á ÐG» ÆGãGº:;GºJ Ûa Ücbd ¹Gü º "Gà O ÎÏÐ :; ç"$Ûe ! HIÏÐ :;f )ghç iCj  2.3.1 ù  2.3.2 ºklmn Û ÇÈopµ ´Ê&GÀqHIGÏGÐ :;Gº r³ç Ñ që \ ^ (2.3.3) Û éî ë Ñ q s ÝÓº r³ç ÇÈ = è opt (2.3.1) GÛ Ð A ëzGÎ Ñ {´uv ¹ [ºwGÑ q¹rGü ³GçMÛà}x~ y Û HIGÏGëÐ K :; zP (B|A) μòÙÚ º Ûë 2 º | º Q º Ì G Ç È A xHIGÏGÐ :;GºJ3 HIGÏGÐ :; ç ë Ñ qGà
A ' º ¼GòGÙGÚ Ì ¾H IÏÐ : ;º r³ç q r³ N D ^ à O % /0º H I Ü Û - õ -rÛ ÇÈop ç æ3 ÁÂÃç 2.3.3 ÜC & 7 ÁC ù 3 ÁÛ Ü i D 3 Áçlá âa Ü:ÌÑ ëÛ¸a 1 ëC º:; ç É ÇÈ Ê A a Ü & Ñ ÁÎ º ÐÛ Ê B 3 ÁÎ 1 ÐÛh 3 HIÏÐ :; P (B|A). Î$ ÇÈ Ê Ω Ñ {´ 2º¡| [ 2 º k=1
¢£¤ ¥¦§
54
ºQ Û ¨â |Ω| = C , |B| = C C = 63. è é Ð a © FÁSÎ A, ¶ a op Ð Õ ç “& Ñ Á Î Á”à ®ëªCè é "k $Î “« ¬ & Ñ ¶ |A| = C”, − C F=85. ¯oA pÝ µ B ⊂“A, ° & 3 AB = B. üà ”,ÇÈ ± Ê|A¸ | = É C , , P (AB) = P (B) = . P (A) = = = ë x ² Ï Ð Û I S :;ºÔÕ 3 10
1 3
2 7
c
3 10
c
3 7
|A| |Ω|
|B| |Ω|
85 3 C10
³ ë Û Ç È ½ ± ÊK
63 3 C10
&
. Î ¼ ò Ù Ú Û x ² I A´ (2.3.1) µ¶ = = . P (B|A) = ç ÇÈ3·<|¸/0 2.3.4 Þ n ¹ º ¸º 2n Á » ¼ p ÀÀ ½ ¶ Û ¸ ¾ ¿ ½ À n Á Á º : ; ç ÉkÇÈ à 1.5.6 ÜCG ¹ m ò 0º ÀÁ kl ÛMüà \^:;ºTÃÔG ¹ wÑ Á kl ç.Ä î Ê Ω & »½ || [ ºQ Û ØÅ K 2n Á»ÆÀ Ñ ÇÛ îÈ ÷ ÔÞÉ 2k − 1 Á» ËÉ 2k Á»Ê½ ¶ Û k = 1, 2, · · · , n. S ëË Ñ qÆ ÃF è Ñ q½ || [Û ¶ |Ω| = (2n)!. Ê A ¾¿½À n ÁÁ º Ðç ØÅ á Þ n ¹º¸ z'ÌÍÛMÊ A É k Í º¸ ½À 1 ÁÁ º ÐÛ S ë A=
n T
P (AB) P (A)
P (B|A) =
=
63 85
|B| |A|
|AB| |A|
63 85
k
Ak .
Û 1 Í º¸ ½À 1 ÁÁÛ Ê é S & Ñ Á k ∈ {1, 2, · · · , n}, Î Æ ã à 2n Á» º Æ ú Ü Û 1 Í º¸º ÀÁ»Æà É 2k − 1 ùÉ 2k Á EÏ ¾Û Ê |A | = 2n(2n − 2)!. "$ é
k=1
A1
1
|A1 | |Ω|
¸ P (A |A ), ôhàá:â 1 Í º¸ ½À 1 ÁÁ ºäåæ ÛM¸ 2 Í º Ç È 3 ¸× ½ h ½ À 1 Á Á º : ; çÑÐ î a 1 Í º » ¸ áÒÍÔÓ]À 1 ½Á ÀÁÛ ÇÁÈ Á ± Ê Õ ÇÖ 'Lç Û ëÙGFÛ ÇGØÈæ׺ hGn −à 1A¹Ú º' ¸º·:< ; ÙGÜ:ÚGº ¾xÑ HIºG¸ ÏGÐ :;G1ºJº3 /H0 IGÏGÐ :; Ç'ç CS üà ºäåË s 3ºäåÛ ®ÜÝÛ × mÞº¸A Î P (A |A ) Û °ßm Ü Í ÛMôâ n−1 ¹ P (A1 ) =
2
2
=
1 2n−1
.
1
1
» ±
P (A2 |A1 ) =
P (Ak |A1 A2 · · · Ak−1 ) =
S ë C:;TÃÔÜ:º
=
1 2n−3
.
1 1 = , 2[n − (k − 1)] − 1 2n − 2k + 1
(2.3.6)
P (A) = P (
1 2(n−1)−1
n \
k=1
µ
Ak ) =
n Y
k=1
k = 3, 4, · · · , n.
1 1 = . 2n − 2k + 1 (2n − 1)!!
3 7
55 à Á kÃÜ Ûà)ü' \^AÚ ' º:; ÙÚHIÏÐ :;º ¿áç 2.3.5 à H I ÜÒâ ã n ä Ûæå L,Ó.ç Û Àþ æè z É àé Ûæê “ë Î 1 « 10 º 10 ÁÛB» ¹ ì ÍÎ 1 º íBàé Ûîê “ë Ü ” ãì Í Üé ” ãì ÍÛîÎê 11 « 20 º 10 ÁÍÎ Û » ¹ ì ÍÎ 11 º í Áþ$ ÛBæ»ï Û ô¹à ÍÎ 1 −10(n − 1) + ”1 ëº ÜÛ ” nã=ì 1, 2, · · ·10(n . −ð1)+¹1ÛM« à10n é º 1 10Û “ëÜ ” & ñì O Áç þ[ ÁÞè ÛMz »A Î É ¹àÍé Î 1 − ÛòÛ ê “ëÜ ” ãì ÍðÎ ý10(n − 1) + 1 :
M Û àé « 10n º 10 ì nº n = 1, 2, · · · . Ý Û “ë à ” A ÎÙ º ç"þ[üà ÇÈÞè z A Î É àé 1 − Ûcê “ë 1 ÁÛ2» D ëÜC ¹ Ñ ÁÛ Ü ” ãì ÍÎ 10(n − 1) + 1 « 10n º 10 ý :ÛMàé 1 Û “ë à ” A ÎÙ º:;9S 1. ý Ì ç n = 1, 2, · · · . ݱ É Ê E àé 1 “ë à ” A Ù º ÐÛ S ë E àé 1 Û &ó ¹ º Ðç î ÛMÎý P (E) = 1, × ý P (E ) = 0. “ëÜ ” Ê A àé 1 k ÍÄGà ë Ü ó ¹ º ÐGÛ S ë E = S A . C:;ºÓó 12 , ôô ± û Ó â S P P (E ) = P A ≤ P (A ) . ÊÎý P (E ) = 0, × ý P (A ) = 0, k = 1, 2, · · · . CS ý à ÜÝÛÊý P (A ) = 0 ÎÂç Ê B àé 1 − 1 Íó ¹ º ÐÛ¨â& A = T B . o pµ T B ⊃ T B , â { T B , m = 1, 2, · · ·} ë æõº Ð ä úÛ °C:;º Óó 10 , ô¾½ö Ó â T T §2.3
1 2 3 4
1 2n
1 2n
1 2n
c
c
∞
c
k
k=1
◦
∞
c
∞
k
k=1
c
k
k=1
k
1
1 2n
n
m
m+1
n
n
n=1
m
n
n=1 ◦
∞
1
n=1
n
n=1
P (A1 ) = P
∞
m
Bn
= lim P
Bn
.
ÇÈ÷3 ¸ P ( B ). àé Û ëÜCã ' ì ÍÎ 1 « 10 º 10 ÁÛ · 1 Íó ¹Û Ý Û$ × & 9 q r Û ° â B Æã P (B ) = . · àé Û 1 ÍÄó ¹Û Ý à B Æ㺠ÏÐ æ= & B Æã Ûø$ ë Ücù & 19 ÁGÛ ° ï ð ÏGÐ º r × & 18 qGç cSGÇGÈFGº ëGà AÚ ' º:& ; ÙÚÛ Êx²¸ÏÐ :; r ¸¹ º B Æãº:; ôÎ “ÏÐ :; ”, ° m T
m→∞
n=1
n=1
n
n=1
1 2
1
1
9 10
3 4
1
2
2
Û · àé 1 − Û 1 Í Äó ¹Û Ý à B B · · · B Æ ãº Ñ Ò D ÏÐ æ= & B Ï Ð Æ ã ÛÒ$ “ëÜ ” ù & 9(n − 1) + 10 = 9n + 1 ÁÛï ð 1 2n
n
P (B2 |B1 ) =
18 19 .
1
2
n−1
k
¢£¤ ¥¦§
56
º r × & 9n qÛ ¶ ÜÝ D & P (B |B B · · · B ë x ² S :;ºTÃÔ Û µ n
P
m \
S ë &
Bn
n=1
!
= P (B1 )
n=2
∞ \
P (A1 ) = P
Bn
n=1
CS Ê
m Y
!
1
2
n−1 )
P (Bn |B1 · · · Bn−1 ) =
m \
= lim P m→∞
Bn
n=1
∞ P
!
1 9n+1
ñ TúÆûºüýþÝ ÛMâ Q n=1
P (A1 ) =
∞
=
9n 9n+1
.
m Y 9n 1 = 1− . 9n + 1 n=1 9n + 1 n=1 m Y
= lim
m→∞
m Y
n=1
1−
1 9n + 1
=
∞ Y
n=1
= ∞.
1−
1 9n+1
=0.
» ± ý ÿ Q ¾¿ÛMôâàé 1 Û P (A“ë )à = ”0,A kÙ =º2,:3,;· ·9· S. 1. O/01± Ê ^ÜC º3 ¿Û ¾ º  2.3.3 ë : ; < : Ü º Ê ºº ¿Â ÃÇç ¶ æÑ Á÷ 0ç Ü ¹ü º Ã Ý ë & È º ^3 º 2.3.6 (Poly´a ) Üc & a Á c ù b ÁGÛËô GÑ ÁGô Û ½G» Û c ÁG¹»' ÁÑC i ÜÛM þ$ uÎ 4 ÇGçGý É n=n +n n Ü ù n º:; n=1
1 9n + 1
1−
k
1
2
Cnn1
1
Û Ü ± à Üc
2
a(a + c)(a + 2c) · · · (a + n1 c − c)b(b + c)(b + 2c) · · · (b + n2 c − c) . (a + b)(a + b + c)(a + b + 2c) · · · (a + b + nc − c)
É ÇÈ Ê A “à n = n + n ô Ü Û ¹' n ÁC ù n ” º Ð ç Ê A à É k ô ¹C º ÐÛ S ë A ëà É k ô ¹ º Ðç ^ Á ÕÖ
A ' º :; ÙÚ º r à ÑÛ ð \^: ;ºTÃÔ ¸ 1
2
1
2
c k
k
P (A1 · · · An1 Acn1 +1 · · · Acn ) a(a + c)(a + 2c) · · · (a + n1 c − c)b(b + c)(b + 2c) · · · (b + n2 c − c) = . (a + b)(a + b + c)(a + b + 2c) · · · (a + b + nc − c)
y : ; ë “à n ô ÒÜ ¹ 'tÒÛ à ¶ æ3º n ô ÒÜ ¹ ' ë à “ n ô Ü Û & n ô ¹'C Ûa Ð º :; ç Ð A Ý 1
2
1
” n2
ºô
.
57 ¹& ' q” º G » Ðç."$ hÛÕ#Ö q “ n ô ¹'CÐ%Û ÊnGôÛ" ¹$ '"h ! ¸” ù º : ; C P (A) 9 S º ±C2GäGÁ å Ð º : äG;åÌù $ ç F ºS Ë Ñ q ê Ôºäå Û& ÇG^È Á ÕÖ
A ' º:; ÙÚ º r Ã Û 1 ð \^:;ºTÃÔ ¸a :; Î §2.3
1
2
n1 n
n1 n
a(a + c)(a + 2c) · · · (a + n1 c − c)b(b + c)(b + 2c) · · · (b + n2 c − c) (a + b)(a + b + c)(a + b + 2c) · · · (a + b + nc − c)
ô 1Ë
Ê 9 Ûò"$
P (A) 9S P (A · · · A A ···A ) M Û ô ý ç º C ' §2.3.2 (UV)*+ Bayes )* ÇÎ2Ȩ H-I ,-. Ñ) /0 Î ÇÕ1ÖGºÛ: ® ; H I / 0 Û ë Á ÛÑêê Þ L È ) k Î&Ñ4/5 06 ç ÁºGÃäGç å ý4 :;J Ñ k31/0Gº ÷ Ñ 2.3.7 &ÀÁ ÃÛ à ÉÑ Á ÜC & 7 Á7Û 2 ÁC ù 3 ÁÛ à É Á ÜC & 5 Á7Û 4 ÁC ù 3 Áç ÉÑ Á ÜC ¹ 1 Á ãÉ GÁ Ü Û É GÁ Üc ¹ 1 Á 3 çG¸ É GÁ Üc ¹ º Î7 º:; ç ë Ñ Á ÇGÈ ó8. mGº/0 ÛMà Á /0 é Ü Û:9©'GÀGÁÊ; 4 Ç º
P (A1 · · · An1 Acn1 +1 · · · Acn )
(1)
(2)
1
n1
(1)
c n1 +1
c n
(2)
(2)
1
2
3
3
k
k=1
P (B) =
3 X
P (Ak B) =
3 X
P (Ak )P (B|Ak ) .
(2.3.7)
ë Á< º| [Û ÊÎHIL Ⱥ:; Û × Þ ¼òÙÚ 1 É Ñ C & ω B À º Q Ω , xIJ : HI Ì ç"$ GÎ'HI P (B|A )PÝ(A± )à = Ð , AP (Aác ) =ÆGã ,ÛP(A É ) =GÁ . à Ü"º º )K& AÚºäåÌæ Û ÁHI Ì ç©ÊHI P (B|A ) ÎÂ É CS A Æã Û Ê É k=1
CSÎ
k=1
A1 , A2 , A3
(1)
1
1
k
7 12
2
1 6
3
1 4
k
1
1
¢£¤ ¥¦§ Á à ÜML û ' Ñ Á7 Û Þ A Î 13, & 6 7 4 3 Û ° P (B|A ) = » ± ÊI P (B|A ) = , P (B|A ) = . Þ ¾¿HI | [ $ã (2.3.7) ÛMôâ P (B) = · + · + · = . ë Ñ Á ÇÈ ó ^ mº r Ã Û à Ár ÃÜ Û ÇÈ K Ñ Á 0 Î 1º: ; H I /0 ) k Î ÑN ú¨ S HI º5O çMÎ' Þ| Ár Ã Û ÷3G ¹ Ñ Á ÔÕ ç Ö× 2.3.2 Ø A , A , · · · , A ë :; ÙÚ (Ω, F, P ) Ü:ºÑP ÐÛ ß L È ë F ¼òÙÚ Ω ºÑ Á)QÛMþ[L È ÀÀ Û& S A = Ω. àRhÛ ± ÊK)Q º:@MN . ± úÁ Ð (ô n Î ∞) ºäB ç \^F ¼òÙÚ Ω º )QÛ ÇÈG ¹þ æº:; HI JÉ Öÿ 2.3.3 ((UV)* ) Ø (Ω, F, P ) Î :; ÙÚÛ A , A , · · · , A ë F Ω º Ñ Á)QÛMþ[ P (A ) > 0, k = 1, 2, · · · , n, ÝF ¼S B ∈ F, 1 & 58
6 13 .
1
5 13
2
7 12
1
4 13
3
2
6 13
1 6
5 13
1 4
n
4 13
64 156
n
k
k=1
1
2
n
k
P (B) =
à ± ú äBæ Ê è D & É P (B) =
n X
P (Ak B) =
∞ X
P (Ak B) =
k=1
n X
P (Ak )P (B|Ak ) .
∞ X
P (Ak )P (B|Ak ) .
(2.3.8)
k=1
Á Ô º ý C ðÛ (2.3.7) ëa n = 3 ºT ÂÛ ÇÈ á:àU ª G ¹' y º ýW VXçYZ ð,ÓW[ Û Àý :ç  2.3.7 ºklmn Û ÇÈ .'® :;Jº\ 4ç:à Î^ y J Û ß m èé op e !¡] Ω º )Q {A , k = 1, 2, · · · , n}. þ[ ¡] é Û Ý ðÊ^. Ú HI º"_kº ç æ3 Ñ/ ÂÃç 2.3.8 `babc ºWÉ Ñ Û Û H Íbd Ú ãe » Ñbef Û eWd # Þgbe d º , , ô f ; ) ý Î 1%, 1% ù 2%. ü y cefÜÒ Ñ ÐÛ]¸y ef ë ô fº :; ç É Ê Ω & ±2º| [ÛMÊ B ¹ ºef ëô fº Ðç / 0 Ûà S Û H âÍy deÚ f ë ÁdGÐÚ ç ãeGë º ç S ë ) ý ë Ê A , A , AÁ)Q Ûy ef & ë É Ñ ãeº S A , A , A F Ω ºÑ k=1
k=1
k
1 2
1
1
P (A1 ) =
Þ L È$ã
1 2,
2
P (A2 ) =
ÛMô (2.3.8)
ÇÈ3 ;ö ·<
3 P
k=1
P (A3 ) = 13 , P (B|A3 ) = 2%
P (Ak )P (B|Ak ) = 0.01 · ( 12 + 31 ) + 0.02 · Poly´ a
º Ã ç
3
3
1 3,
P (B|A1 ) = P (B|A2 ) = 1%,
P (B) =
2
1 6
≈ 0.0117.
1 3
1 6
,
§2.3
59
2.3.9 ( Poly´a ) Üc & a Á c ù b ÁGÛËô Üc ô Ñ Á¹ÛøC ½» c ÁÎ » Ñ i Ü Û þ$ u4 Ççøý É à É n º:; . É Ê A à É k ô ¹tÒ º ÐÛ S ë A ëà É k ô ¹ º Ðç ÇÈ 3 F n z _ `ç î & P (A ) = . hØ n = k −1, k ≥ 2 | < À Û hý n = k | < ½ À ç ÇÈ Ê A ù A zÎ F Ω ºÑ Á )Qç o s 3 & a + c ÁC ù b Á ºÜ x÷ Ý pÛ$ ±à Þ P (A |Aô ) Àë¹t Ò º : ; Û " $ _ ` hØ â P (A |A ) = , k−1 É » i & P (A |A ) = , S ë ® :;J a a+b
c k
k
a a+b
1
c 1
1
k
1
k
k
a+c a+b+c
1
a a+b+c
c 1
P (Ak ) = P (A1 )P (Ak |A1 ) + P (Ac1 )P (Ak |Ac1 ) a a+b b a a = · + · = . a+b a+b+c a+b+c a+b+c a+b
"$ |<FÑ { n À ç ¾ k lÜÒF Ω º )Q º ¡ r o p ç ª ¨j ºÑ ÏkXëK A ù A zlÎ F Ω º )lQlçM"à Î $q ¡ lÌl× æ âÛm ðlÊ \ & ^ _ ` hlØ Il¹lÏlÁÐ : Ûn ; P (A |A ð S âma )Ü:ù º PC(A |Aù )."_ çÊ uÇD È ÛMà A ù Ü A Æa ã+ bº+ä(kå−æ 1)cÛ Ü:º ù "_kÝf )opç Á q ô Ce !¡ )Qr º gh Ó ç 2.3.10 9rtsuCvàtw º 2 xyz ç{|û ÑP}~ Û ÉÑ ¼ p ÀÀ FÍW Û îÈ 2 x Z ¼ p F4 Ç É ÍW Û:þ Þ È $ æï Û µ«É n 3
Ñ x Îç hGÔ Ë Ñ x ç{Gà# ÍÜ ö1 ë 9±2 çtsuCvà PÍWÜ Ê8 :; ç É à| v Î 2 ÛtsuCvà P ÍWÜ Ê8 :; Î p , È à ÉÑÍWÜ Ê8 :; Î q . ÇÈ3F n 4 Ç ·< ç þ[ n = 1, ÝÑù × &tsu Áv|û ÍW Û ÈÑÔ à ÉÑ Ê8Û Ê p = q = 1. þ[ n = 2, Ý &9rtsuCvàtw 4 Áv|û ÍW ç) ý Ê A ù B È à ÉÑùÉ ÍWÜ Ê8 Ðç S ë& p = P (A) + P (A B) = P (A) + P (A )P (B|A ) = q + (1 − q )P (B|A ). î W Û sÕuCÖÛMvâ à ÉÁÑv Ê8 Û é r é & È qà ÛÉtÑsuCÜ vÎ ÑÎ F ç ^ Ìr Í) P× & qÛ Ê 4 þ [tsFuC v à 3 ÑF × &F à v & Ê 8 M Û U Ñ ' q = . ÉÛÑ ÜW $ × È & Áv , Ê G 8 1 F4ãÉ Í cS É Ü Í
k−1
c k−1
k
k−1
c k−1
k
c 1
1
n
n−1
n
n
n
1
c
2
2
1 3
1
c
c
2
2
c
¢£¤ ¥¦§ Û ÛÊ×â h È124ãÉ ÛU ÈÑÔ Ê8ç Ê P (B|A ) = . Ñ3 p = q + (1 − q )P (B|A ) = + · = . þ | [Û ÎÇÈ & W ì ÉFÑ { n, 1 èé &
60
c
2
2
ü à å ÇGÈ3^ _` G ç hØ p =È ö , ÇÈ3 ÉÑÍWù ÍWÜ k
1 2k−1
c
2
pn =
1 3
2 3
1 4
1 4
1 2
1 . 2n−1
à ý Á ìGç é ç nÄ =) 1 ù ý^ Ê8 n= k Ð+ 1ç S äëB &
GÛ |< ácÀ tsuCvà Aù B
n=2
pk+1 = P (A) + P (Ac B) = P (A) + P (Ac )P (B|Ac ) = qk+1 + (1 − qk+1 )P (B|Ac ) .
uÒvà ÉÑ Ê8Û é é È à ÉÑÜ Î Ñ F ç ^ Ì Í) P ÒS Õs Ö ÛMâ 2 Áv F r Ñù & k+1
(2k+1 )! 22k (2k )!
qÛa Ü suCvÎ ÑF F r & qç Þ ÊÛMô qk+1 =
(2k+1 − 2)! 22k −1 (2k − 1)!
2k+1
2 2k 1 = k+1 . (2k+1 − 1) 2 −1
þ [suÒvà ÉÑÍMÜW &Ê8ÛU à È ö WÜ Ê 8Û R çW v à ÉÑtWë ÜW ç {Fx ²Ûs a 2 ÷ − 2 x Ç Z Ñ m ç 4ã æ× Ñhttsu v 2 x 3tW Ê8 Ý4 W ë & È È ö Û U à ö 124ã tW WÜ :; p , k
k
k
S ë |Q _ ` h Ø ôâ
P (B|Ac ) =
1 pk . 4
1 pk+1 = qk+1 + (1 − qk+1 )P (B|Ac ) = qk+1 + (1 − qk+1 ) pk 4 1 1 1 1 1 1 = pk + (1 − pk )qk+1 = k+1 + (1 − k+1 ) k+1 = k . 4 4 2 2 2 −1 2
|< à n = k + 1 Ä î À ç ÿ Q ÛMâtsuCvà W Ü Ê8 :; Î
pn =
1 2n
.
61 à klÜ Û¢¡ 1 ë A ù A (ôtsuCvë£à ÉÑ Ê8 ) zÎ F Ω ` )Qç Çq _F ` )Q ç ¡ r & \S á n = 2 ä B Û¤ & \ S ^ _ hØ4 m¥ ¡ 34Ñ5·<¦ 2.3.8. 2.3.11 `acÉ Ñ Û Û H Íd Ú ãle Ñelf Û ed # Þgledl ô ) ý Î 1%, 1% ù 2%. üy cefÜCÑ ÐGÛ§Güëô , , , f; f ÛLë Ñ ÍdÚ ãe:; ç ¨ B y ef ë ô f ÐÛ ) ý A , A , A y ef ë ÉÑ Û Û H ÍdÚ ãe Ðç¡ h 3 ÏÐ :; P (A |B). CS á:à ¦ 2.3.8 Ü
P (B) ≈ 0.0117, üà /0 1 Û¡ & §2.3
c
1 2
1 3
1 6
1
2
3
1
P (A1 |B) =
0.01 × 21 P (A1 B) P (A1 )P (B|A1 ) = ≈ ≈ 0.427 . P (B) P (B) 0.0117
/ 0© a k l % & ÑÔª«Ó Û þ [ | Q¦ 2.3.8 ÜÒF P (B) Ã Û ¡ ± : Îþ æÔ ¨ Öÿ 2.3.4 ( Bayes )* ) Ø (Ω, F, P ) Î :; ÙGÚGÛ {A , A , · · · , A } ë F )QÛMþ[ P (A ) > 0, k = 1, 2, · · · , n, ÝF ¼S B ∈ F, × h P (B) > 0, Ω Ñ¬ 1 & 1
2
n
k
P (Ak )P (B|Ak ) P (Ak |B) = Pn , j=1 P (Aj )P (B|Aj )
k = 1, 2, · · · , n.
(2.3.9)
¬Ô ýt M ðÛ × h Þ ÏÐ :;ÔÕ® ® : ; J |Q ^ ô ± ç ¡ 3 ^ Bayes Jk0Ñ/¦¯ ç 2.3.12 suCv°Ú- ^ E-mail ( ±W¯² Ð ) Ê%³ N Û ´Ô ൠ. F r ² Ð é¶ ô G iW· (ô i Ѭ E-mail ). CS¸ X /0 ÛòË n ¹ E-mail Ü ,& 1 ¹ 2 à 鶺 ^µÐvçs:à ` +§' 1 ¹ E-mail G u:Û ³ óà é¶ µ .tu iW· çtu:à é¶ µ.'tsW§ G E-mail :; ç ¨Bà ¬/0Ü Û9©& ¬ !GÔ»¼ ¨ Ѭ ë½sW§ G u E-mail ÑÔ2 à é¶ .^tsCáç «S u Ñë £Ô2 i à é¶ .^tuC® áÛëtu ë £i µ .E-mail 'tsW§ 3 E-mail , ôà “µ. ” ® “ i E-mail , ÝÛ 3 S °Ú Û ®ë Ñ q !ÔRN ç ” E-mail ¡ A u"à é¶ µ.'½s§ G E-mail ÐGÛ B s"à é ¶ µ.'tu i G E-mail ÐÛh 3 ÏÐ :; P (A|B ). î A ù A E À' ѬF Ω )Qç C0Ü ÏÐâ c
c
P (A) =
n−1 n
,
P (B c |A) =
1 n
,
P (B c |Ac ) = 1 .
62
Bayes
¢£¤ ¥¦§
J â
P (A|B c ) =
P (A)P (B c |A) = P (A)P (B c |A) + P (Ac )P (B c |Ac )
n−1 1 n n n−1 1 1 n n + n
1
=
n−1 . 2n − 1
&vÙÛ Bayes J ë ^3k3 “ á:â | [Ûò)¾s" ” /0 Û ¬ Ù Ã F &m ç©à ¬¦0Ü Û:s:à é¶ &µ.tu i G E-mail ( ëáC§ ã ÃÛ q Ûë ô | [ &),µU.t u i éî , Å ÛÀ¿ÁëÃ"Â! s "HÃÄI!kÏëÐ u &µ. E-mail C'¨ÅuWµ :}Æ ; ÙP (A|B ) =.' G Î E-mail ßm Û ÑbDZ2 ëtu A E-mail ±2Ó P (A|B ) = < ; &µ. E-mail , "$ & G i E-mail . 2.3.13 ` qÈ É ; Î 0.5%, ß m <ÊËÌ y Í Ë ; Î 5%(ô õ É<ZÊ Ü &[Ð5%Î ÑvÛ<Ê | [ÎÎ &Ó $Û É Z Ü & ç 5% v<Ê | [ÎÏ Ó ). üâ ` v | !É :; ¨ A É &$ ÒÓD B <Ê | [ÐÎÑ Ò çD¡ h ëÔ Ò:; P (A|B). á:âÔ Ò â P (A) = 0.5% , P (B|A) = 95% , P (B|A ) = 5% . ë op A ù A F Ω Õ¬ )Q Ó° (2.3.3) c
c
n−1 2n−1
1 2
c
c
P (A|B) =
P (A)P (B|A) 0.5% 95% = = 0.087 . c c P (A)P (B|A) + P (A )P (B|A ) 0.5% 95% + 99.5% 5%
¬| [
v pÖ×Ó as"à S vØtÙCy É ; FÚ Ó¤Û Ð 0.5%, Ü <ÊËÌà Í Ëáâãä Ó Ð 5%, å®Éæ áç èé 10 ê ° l Ý Þ ß ß ëìDíî ïtÙ ðñtèWòó â ë éð¯ô 11 êõ ìDö ¬÷øùú ¡ ÓDûü Ê ýþ ÐÎÑÿ Óæô áâ Õ ì æô á õü ÿ á ØÙWà æôæ á ìö æô!"# ô $% '&() ýþ*+ ÿ',,â %-.ì ü ï 01 23 åé456789 ìÀö: / ï é; 18 <=>?6 Bayes / @A Bayes BCô Bayes D â EGFIHJ á KLNMâ ßé KLOPQR S î è ìUTVWX YZ ö: / ï î é & T[\]^ `_ T ô :abc 7de ÿ í T ôfgGhIYi \ YZjkô ì lmn ; ö o k7p ö : / ï qNrst : ßu ö o n :nw ô Wx (y ), î {P (A ), k = 1, 2, · · · , n} é v A ,A ,···,A mö :nwWx
nw+ { W| L'} ~ ì n (y )ô zô ÷ ü á û ö : ßuõ :ýþ B \ m ß á {P (A |B), k = 1, 2, · · · , n} ö :nwWx nw+ {
ö á } k n ô z
j ô \ { Lã \ ì n í ô ü á ì î Bayes / ï x õ ü á ô v A ; ö {'ì $% ôé \ k í ö {~ ü á E − mail æ!"ô j 1
2
n
k
k
§2.3
63
c KL '¤¥ áKL hô : ü á@ ô¦ 7 hYjõ 7¡¢£ õ ì à@¦ õZ§¨©DôªD7ô«¬k ®¨© } Bayes @ ô ë ¦ ì Bayes @¦ áKLOP ¯¨`© ô °±7p '&² 7³ OPÿ ¯¨©ô ë ¸ ²µ KL ² °´ jõ³ ¶ô ¢£ å· ô¹;¯¨Iº`»¼ ì\ k ½ %¾ é ~ ü á ô p¿ ² 7 ò ÀÁ´ ò  @¦ ô ÃÄÅÆ ì ÏÐ ÈÉ Ê õ Ç» » YjËÌòü Bayes ¢£ &LãÍÎ ë Õ KL@Ö ôô ×Ñ £ Ò Bayes ¢£òü Bayes ¢£ôø ÐÓÔ x ä ì é;ØÙ Ú ô ÛÜ Ý]: @¦ ô 7¡¢£ ì \
Þß 1. 2. 3. 4. 5.
2.3
àâáâãâäâåâæâçâåâèêéâëêìêíâîðïêñâòêó 3 òâåâôâíâõâöâ÷âîêøùâóêäêåâîðúêûâüêóêñâò çâåâíâýâþâÿ â í âôâîNøùâô 7, âî úâóâñâôêí
1 íâýâþâÿ 3 â í âôâîIø ù ê í êî úêûêüêóêñâò 6 âíâýâþâÿ "!#$ê í % &ê ñ ' (ê* î ) +, - ./ #êÿð ú , /# 01 2 3 +4 5 67 í "!#$âíâýâþê9 ÿ 8 øN ù % &â ñ ' (ê è : ê< î ;= >êýêþê è ?êA ü @ ñ Bê ã 4 C D E ê ñ F Gê í 3IH 9 î J ñ 3 KILêí ýêI þ p, 8 Jê ñ 3 K L M J N 3 K Lâíâýâ þ O p ; 8Jâ ñ 3KLMJ N 3K Lêíêýê þ . (1) 8âûâüâóâ ñ 3KL M,ê ì P Q R Lêî ú , P Q RLêíêýêþêÿ (2) 8'ø ù JN3KLêî ú , Jâ ñ 3 K Lêíâýêþêÿ øù P (A ) = 0.3, P (B) = 0.4, P (AB ) = 0.5, ú P (B|A ∪ B ). øù P (A) = 1/4, P (B|A) = 1/3, P (A|B) = 1/2, ú P (A ∪ B). Sâó 2n − 1 T U"V 2n TWVâYî XZ.P n TâYî [X\]âè ^âíâîú W ^âí ýâþâÿ ò ê í V ` a b # 1,2,3,4 í cê ò d ê9 î e V a d êéêëêìê9 ÿ Xê ù fê ó êò g_ dâ3 î úâ ó Vâ í dêôâ í % h b # k íâýâþâÿ ijklmnZ. o p A, B, C, qrâé sâñâá t u v p 2
6. 7. 8. 9. 10.
c
c
c
¯ C) ¯ = 1; (1) P (A|C) + P (A| ¯ = 1; (2) P (A|C) + P (A|C)
(3) P (A ∪ B|C) = P (A|C) + P (B|C); (4) P (A ∩ B|C) = P (A|C) · P (B|C).
wxyzr t uâí { pêÿ 11. (j 2.3.6 í| ) }â l ïJ k 3PV~PQ U"Vâíêýêþêé n . 12. (j 2.3.6 í| ) }â l ïJ k 3PQ U"âV í{pqêîUï J m 3PV~ (k < m) OPQ U"V í{â p ýâþâén . 13. _ 4 òV 6 ò U"Vâ ïSâ îXZ . â ñêñ
ê îê û V
êÿúf
k 3 â íâýâþâÿ 14. Sâ ó r òV b òWâ V îXZâ P ñâV î" E s òâ^ íâV ñ` ÿ" S Z P ñV[â X èâ V îUúê J ñ 3 P â í ê V è W âV íêýêþêÿ a a+b
a+c a+b+c
64 15.
ó 2 T ê ôêî9ê J ñ T êô êó 4 ò W V 1 ò Vêî9J N T êô êó 5 ò W V 2 ò VâîJ2Tâôâó 3 òWV 4 òVâÿX-PâñT âôêî" >êô - P ñâ V ÿ (1) â úâ òV Vâíâýêþ (2) øùPâíâèWVâîðú >V AJN T âôêí
ýâþâÿ
16. 17. 18. 19. 20.
âó 7 ò U"V 3 òWVâî` "- P 3 òVâî øùâñ WVâÿ ú¡NV UVâíêýêþêÿ ¢ ñ £ ¤ ¥ ¦ § ¨êñ © ¤ ªêíêýêþ 1/3, § «êíêýêþ 1/2, § êíêýêþ 1/6. ê ¢§«3O¬ ®© ¤ ª q â ¨ ÿUú ¯ ` 4 £¤¥¦â짨© ¤ ªêíâýêþêÿ â ` óâñâòâ V î°\ AU ê W íêýêþê éêÿ²±" ` âa ñêòAUê V î° - P êñVêî [X>V U ÿ9 ú 6 ³ V â O èAUê V íêýâþêÿ 4Câ ´ ñµ â ¶ î<ê û â J ñ 3 X â ò ê C í ·¸ ê ÿ ú f ´ n â3 íâýâþâÿ ๢ ñ¹º¹»¹¼ í¹½¹¹â ¾ ï¹â 2 òâë ì¿À¹â íZ¹âÁ ñâò èâéâë ìâí ÿùĽ¹»âŠﹿÀ i (i = 1, 2, 3), MÇÆn¹¹È¹É¹Ê í¹Ë¹Ì îÎ͹1ÏйÑÒ&¹[X¹Óâ Ô íâý þ α (0 < α < 1). XÏÐÑÒ¿À 1 &Õ[XÓâ Ô î ú ½ »ê Å ï ¿ À i í{âp ýâþâÿ n mÖ×ZØâ t ñâ r îUú Ù Öê ï ê Ú ô& ¸ (â ñâáÛ ) íâýâþ p . i
21.
i
n
ÜÞÝÞßÞà
§2.4
lm% & åæçÐ Dá hãâä è ) p Pé ¢£ê
ë ìíîïðñò ó ôè/ôõôöôè¡ Wô÷ Yh é :$%ôø uôù »89 ÓÔôúôúôû j ü ÿýéþÿ ' ê 4 é % ö & Ω h : é ôè ; ´
¹ é<é ê Ð ¢£pè OP x ü ê ê é # ê$ ~ % &' ´ j ü 1 ( % 2.4.1 !" ) µ %+* ´, - ü 1 ( %+. )/ %+012&'34 +ê 567 n 8 9 : é ; èê <=?> A @A 7 n 8 9 : é BC%ED p = P (A ). FG > A H
M é & L % A Ω §2.4.1
n
IJK N ö :ãó ; èOõP
n
n
c n−1
P (An |An−1 ) =
5 6
,
P (An |Acn−1 ) =
1 6
.
pn = P (An ) = P (An−1 )P (An |An−1 ) + P (Acn−1 )P (An |An−1 )c ) 5 1 2 1 = pn−1 + (1 − pn−1 ) = pn−1 + . 6 6 3 6
QRST % UVWX
JY
NZ[\] W
1 2 pn − = 2 3
1 pn−1 − 2
,
n = 2, 3, · · · .
n−1
^ _`a bcdef W% 0gh §2.4
65 p1 = 1,
pn −
j >kl
1 = 2
iP
n−1 n−1 2 1 1 2 p1 − = , 3 2 2 3 n−1 2 1 + , 3 2
1 pn = 2
n = 1, 2, · · · .
FG .mnopqrst u 2.4.2 U n vxw q \ 2n Lxyxzx{xhx|x|x}x~x% 6xx }x n Lx \ ;xxt <= FG
1.5.6 H 2.3.3 no R s% .m de ; O W / -&Lt > A @A n vw q } n L \ BC% D p = P (A ). .> q} 1 L \ BC% e B H B \ &Lt N : B @A 7 1 vw Ω I J K ; O W P n
n
n
c
pn = P (An ) = P (B)P (An |B) + P (B c )P (An |B c ).
* P (A |B) , M 2.3.3q} Q 6LP P (B) = ; Y P (A |B ) = 0; 7 1 vw q Q 1 \ C3%Eq n% −j 1 > vw q} n − 1 L \ ;%E29 n − 1 vw P (A |B) = P (A )=p , 7 W 1 vw V iP 1 2n−1
c
n
n
n
pn = P (An ) =
bcdef W% 0gh
p1 = 1, pn =
iP
1 pn−1 , 2n − 1
1 , (2n − 1)!!
n−1
n−1
n = 2, 3, · · · .
n = 1, 2, · · · .
¡¢£¤¥¦ §¨l&L© (ª« \ S ( V¬% ® 8¯,°±² ³´ 1, ¯,°µ² ³ V ´ 1, °±² \ ; p, 0 < p < 1, °µ² \ ; q = 1 − p. ¶· J ¸ ¹ ÇÈ ( \º»¼ t FG ½ /¾¿ÀÁ \ C3ÃÄ©Å n 8² I Æ JÉ Ê¿ à · 9Ë n) j Ì \ Á t J u 2.4.3 (ÍÎÏ¢£¤¥¦ ) §©Å V º»¼ t ÐÑ À ©Å Á N ¸ ¹ ÒÓÔÅ O, 56Õ 9Ë n Ì ÒÓ k \ Å K \I ;t J <=Ö> A @A ©Å 9Ë n Ì ÒÓ k \ Å K \ BCt §©Å 2×Ø JC à à B 9à l b 8,°µ² A ÙÚ IÆ a 8,°±² §2.4.2
k
k
a+b=n ,
a−b=k .
Û ÜÝ Þ ßàáâ : 2 P a = . : N a ã S ª à j >äl n k \åæçèé 9 Ãëêl ìt j > ( 1í n k éåæ ; C p q , P (A ) = 1í n k î åæ . 0, 9 P Rïð \ poÃëñ R òó l p = q = . j > FG, ô1.2.8 õ \ Ð Lö e t º»¼ 1.2.8 K u 2.4.4 (÷øùúûü¢£¤¥¦ ) §©Å V º»¼ t ÐÑ À © ¸ ¹ Å Á N ÒÓ k \ Å K, 0 < k < m. 1í Õý Ð9Ë ² I ÒÓÔÅ O ¯ Ò Ó m \ Å J M , Êþÿ ñt FG U ¶ |LÅ · t 5 Æ 6Õ ÒÓÔ J J Å O H Å M ÿ \ ;t <=Ä> E @A ©Å : ÒÓ k \ Å K Ù \ B Å M C > A @A Õ J ÿ \ B C > B @A Õ ÒÓÔÅ O ÿ \ BCt .> H @A ©Å 7 1 ,°± ² ³´ 1 \ BCà N H k ©Å 7 1 ,°µ² ³´ 1 \ BCt D p = P (A|E ) , q = P (B|E ) . Ð Là gh ; O W e N C; ( > HH H \ Ω I J K J C; ; ), P (A|HE ) + P (H )P (A|H E ) , gh HE k p =: PÒ(A|E Ó )k=+P1(H)P \ Å. Ù \ BCà H E k : ÒÓ k − 1 J \ Å. Ù \ BCà j >J VWk p = P (A|E ) = pP (A|E ) + qP (A|E ) =p·p +q·p , k = 1, 2, · · · , m − 1. ST ÇÈà P 66
n+k 2
n+k 2
n+k 2
n
k
n−k 2
1 2
k
c
k
k
k
k
c
k
k
c
k
c
c
k
k
k
1í
UVW
k−1
pk+1 − pk =
p C 1í
k+1
p = q = 21 ,
q (pk − pk−1 ) , p
VW @
p0 = 0, pm = 1,
bcde p 6= q,
iP
pk =
k = 0, 1, 2, · · · , m − 1 p1 =
k
k−1
k = 1, 2, · · · , m − 1.
{pk − pk−1 , k = 1, 2, · · · , m − 1}
k m,
k = 0, 1, 2, · · · , m.
WÃgh (2.4.1)
pk+1 − pk =
K
k+1
k
k q p1 , p
6 H Ã de p
pm = 1, =
ª t
>
k = 0, 1, 2, · · · , m − 1.
(m−1 )−1 X q k k=0
p0 = 0,
(2.4.1)
P
1 − pq m . 1 − pq
(2.4.2)
§2.4
U
^_`a (2.4.2)
W K
k = 0, 1, · · · , j pj =
V!Ã FGP M = K
67
6 H Ã de VWÃ iP
1− 1−
j q p
j = 0, 1, 2, · · · , m.
m , q p
l
k = 0, 1, 2, · · · , m, k p = q = 12 ; m, k q pk = 1−(qp )m , p 6= q. 1−( p )
ïð >" P = K
l
k = 0, 1, 2, · · · , m, k , p = q = 12 ; 1− m q k q m pk = ( p ) −q( pm) , p 6= q. 1−( p )
# V!$"pí >% ÐLl& \ po= k = 0, 1, 2, · · · , m, ' l K p +q =1 . à |y * l \º»¼ ÃÖño©Å #+,xÁ ٠à '-. ¶ ( ) F G / j à # ¬ ¯0¯1 /p2t §©Å V º»¼ à p = q = . ÐÑ À u 2.4.5 (345 6 ¢ 7 8 ) ¸ ¹ ©Å Á N ÒÓÔÅ O, 56Õ 9Ë 2n Ì ÒÓ I 2k, 0 < k < n \ ÅÃ9: ¼ J R; =< l>? R ÒÓÔÅ O \ ;t <= s e N@A ;õt CBCD VCEF ÒÓ H à > X « @A 9Ëà > ¸ G ©Å j Á t N ©Å \ ®ÐCI ì \ ¬CJCK ö BCD V \ Ð CL Y « @A K V ® C Ð O Ð O t NCR CS Ø L \ Q P \ 1 ¯ −1 ¹ ' ¹ k (· JCj MCl N ), \Q¹ T à J © Å 9 Ë Ò Ó Ω MQ\N ÅÃ: ¼ |Ω| R=; 2 . > l>E ? R @ ÒA ÓÔÅ \ B2nC Ã Ì N J 2k, 0 < k < n : j lCUCVCWCX C \ = ¶CZ =< ¿ N Å (0, 0), - N OÅ (2n, 2k), C: E MCNCY MCN l [ Åt X «< > A @A ©Å 9Ë 2n Ì ÒÓ 2k, 0 < k < n \ 6 |E |, FG J Æ Å \ BCà > B @A ©Å 9Ë 2n Ì ÒÓ 2k, 0 < k <J n \ ÅÃ: ¼ J R; >? R ÒÓÔÅ O \ BCt N k
k
1 2
2n
2k
2k
2k
2k
|E | = |A | − |B | . M Ã B C A ÙÚ 9Ã ©Å Ã R ; \ 2.4.3 n + k 8,°±² I Æ IÆ Ã > j n − k 8,°µ² |A | = C . BC B \ l [ Å ] Ã \ > | ï Ã 7 Ð ï ©Å 7 Ð , ° MN ' X « J
:
2k
2k
2k
2k
2k
2k
n+k 2n
2k
ÛÜÝ Þßàáâ à ¶ I QR Å (1, −1); 7_ ï ©Å 7 Ð ,°±² Ã`\ X µl ² [ M N ^ M N Åà ¶ I à > D @A Õ QR Å (1, 1). FG mab{hÐ 7_ ï « M N M N V Á N ÔÅ O H Å D ÇØ \f \ 7 ÐL (ÒÓcd \ ) [Åà FGe X « M N N X « \Cg D bCh à ò , Õ kCi Ð QR Å (1, −1) \ 7 Ð ï t b J I C M N ÇxÃjWxí e {xhxÐ 7 Ð ï V Á N ÔÅ O H Õ é X « \ 7 Ðxk L [ÅxÇxØ \kf M N t C ñ l N X « \g D bh à ò , Õ ki Ð QR Å (1, 1) \ ï 7 _ J M N I m à ¶ I K ö ÐÐ \ à j >| ï MN \ o è t M à 7 Ð ï \ o ª n ª n Y M N N ¿ N Å (1, −1), - N Å (2n, 2k) \L \ ªon pt Wí> a @A ¶ ï L V P ¹ kl J , à \1 O \ ªon à > b @A ¶ ï L V ¹ P −1 \ O \ o ª n ò ¹ ¹ J ¹ a + b = 2n − 1 , a − b = 2k + 1 . # M q a = n + k, 68
¶ R ÐmÃ Ê P |E | = |A | − |B | = C gh j > C , n+k−1≥ N kl
n+k |B2k | = 2C2n−1 .
2k
2k
2k
2n−1 2
P (E2k ) =
n+k n+k 2n − 2C2n−1 n+k−1 n+k > C 2n−1 2n−1 .
n+k−1 n+k = C2n−1 − C2n−1 .
C n+k−1 − C n+k |E2k | = 2n−1 2n 2n−1 , |Ω| 2
k = 1, 2, · · · , n.
>V j e \ N X « \g D bh · “bh Ô T ”, $" ª \ ÐIl J M N rstt s j P \ pxo bku ºx»¼ \ ÐLkvw ç ©ÃxWxí dxe · ç Ãyxp K o à FG >Æ zpWX= 2.4.3 \ p §©Å V º»¼ à p = q = . ÐÑ À ©Å Á N ÒÓÔÅ O, > p ¸ ¹ I ÒÓ 9 Ë \ ÅÃ9: ¼ R; =< l>? R Ô @ÅA Õ\ ;t n lÌ = J k, 0 < |k| ≤ n O Wí n k éåæ ; 2 C −C , p = Wí n k î åæ . 0, { FG ä K n H k ' æ ª \ J ] IÆ [ à ÕG' å ª \ J ]\ L vwrs= [ | ïð t FG > de ¶ Lpo;o \ Ð u 2.4.6 (k §x©xÅ k \xºx»x¼ xà p = q = \ S ÅxV k Í k } k ~ k ) x ¸ ¹ I Ñ À 9©Å Á N ÒÓÔÅ O, 56Õ 9Ë n à # ? R ÒÓÔÅ O . ¸ J \ ;t 1 2
(n) k
1 2
−n
n+|k| −1 2
n−1
n+|k| 2
n−1
(n) k
^ _`a <=?> A @A ©Å 9Ë n à # ? R ÒÓÔÅ ¸ \ Á J\ ÒÓ ¾ UV C 9 à © Å 9 Ë A ÙÚ n K k^ + k ≡ 0 (mod 2), 0 < |k| ≤ n . =:
ê \ po M = n =n2m 9Ã l §2.4
P (A) = 2
m P
9Ã l k=1
(2m)
p2k
=2
m P
k=1
69
O
\ BCt ò ,
m+k−1 m+k m 2−2m C2m−1 − C2m−1 = 2−2m+1 C2m−1 ;
n = 2m − 1 m m P P (2m−1) m+k−2 m+k−1 m−1 P (A) = 2 p2k−1 = 2 2−2m+1 C2m−2 − C2m−2 = 2−2m+2 C2m−2 .
V!píà > k=1
k=1
[n]
2 P (A) = 2−n+1 Cn−1 .
X D m%ÐL M N rsl \ t u 2.4.7 § G j lkxlkXk! ] W \k O ]x\k ª g(x) \kT x= g(0) = 0, ¹ = g(j) + α (x − j), j ≤ x ≤ j + i, j = 0, 1, 2, · · · , n − 1, α = 1g(x) M $" » = l f T \ j l ª t FG # º» Ð ¯ −1. L ª à 6 º» BC A \ ;à A @A j \ ª g(x) N WX T = Ø (0, n] =< l v }. G = {g| g(x) <= s 7 Ð 1.2.8 \ t M à G \ ®ÐL ª' ©Å º» [ Å \ MN è K Yöà j > : Vs \ pí M ¼ \ Ð X «< l j
j
0
0
[n]
2 P (A) = 2−n+1 Cn−1 .
2.4 1. 999999y ¡9¢ £`¤¥y 9¦¢ §¨©yª«y¬ p , p ¡ p . 9®9¯ (° ±9²9³ 1/3) ´9µ9¶99j]£j·9¸µ9¹¶ ºj»¼½ ¬y § ²³ º 2. (¾ ) 9®9¯9´9µ9¶9999£¿·9¸µ9¹¶ £ÁÀÂ9ÃĽ9 ¬y 9º¿½9 µÅyÆ9¶9 § ²9³ ¬9Ç9ÈÉ ²9³ 3. Ê9¶9Ë9Ì9Í9Î9§ÏÐ n Ñ9£jÆ 1 Ñ9Ò9¹9Ó9Ô9§ ²9³ ¬ p (0 ≤ p ≤ 1). ¼9Æ n Ñ9Ò9¹9Ó9Ô9§ ²9³ £j·¬ Ûc,Ü Õ9nÖ9→×9∞Ñ9Ê9Ý9¹9§9¦9Þ9Øß9Ѻ ÙÚÀÂ9§ 4. àáâãäÑå©yæâç£j×è×Ñpçöpéº`êÍpëì£`âãîíyï 10 Ñâçð 5 Ñ9ñ9©xæ9£yò9â9ãóyôð9 8 Ñ9ñ99ºyï9â9ç9õ9ö9Ø£Á÷9¥ ± Ò9ÊÏÐ9øùë9úûü9ý õ ö (°ÒʶËÍΧÏУjþ Ó Ô åyÿ£jôíyõö£Ôåyÿ£jôóyýõö ). ÷9¥9§9²9â9³ ç9ô£ Ì üïâç9£÷ ©yæ9çºj»9¼½Ñ©xæ íxç99§ º ± A Æ k µ 5. N £ M ¬y £j¸¬ n §º ± ¹9§9 9¬x §£ B 9 m x 9§ 9º!"£jï#$y¡% #&$x§9à ' ( ) * 1
2
3
k
m
P (Ak |Bm ) =
m . n
ÛÜÝ
70
Þßàáâ
Æ9¶99999 N x 9¡ M 9¢9 9£¿Æ +9999 N x 9¡ M 9¢9 9º ÅxÆ ¶999²9µ9³ ¹9¶9 # ,Æ +9£.- /Í9ÎÖ0¸9Æ+9µ¹9¶ 9º¿»9¼½ 9¬ 9§ º 7. 1 n £23# N y ¡ M ¢ º]Åyƶ®µ¹¶ #,Æ+ £40 Å Æ5+99²99³ ®µ9¹9¶9 # ,9Æ99 6479Õ 8 89£:9ÖÅxÆ n ®µ¹¶9 9£ »9¼9½9 9¬x 9§ º 8. Æ9¶99999 N x 9¡ M 9¢9 9£¿Æ +9999 N x 9¡ M 9¢9 9º ÅxÆ ¶999 % #&$x¯99®9µ9¹ n 9 9£ÁÅxÆ +999 % #&$x¯9®9µ¹ n 9 9º<; =9µ9¹ §9²9 ³ >9 # , ? @9§Æ99º.99ÖÅxÆ99®µ¹¶9 £¿»9¼½9 ¬BA§ º 9. í9óxà C D99 1 E9 9¦ 1 9¢9 9£ ×9Ñ9¸9à C9 D F9µ 1 G H9Ö #&$xº »9¼ I J n Ñ G H9Ö9£]íBC9 KL 2 E9 9£ 1 E 1 ¢9£ 2 9¢9 9§ ²9³ p , q , r . 10. 30 M N O P Q9»£!9 5 M N9¶ R S T£` 10 M N U V W X9£` 15 M N M Y W Z9º[U V9¶ R S T§ MNQ9» \] “S T ”; U V W X9§ M N ± Ù 89§ ²9³ Q] “S T ” ¡ “ ^BX ”; M Y U V W Z9§ M N9ô ± Ù 8§ ²³ Q] “ ^BX ”,“_ ²9` ³ ” ¡ “Ì _ ` ”. 9®&ax¹9¶9 M N£j»¼÷] Q»À¬ b (1)“S T ”; (2)“ ^BX ” § º 11. íx£ óxà c&dBC9£ íBC9 5 cx 9¡ 2 c9¢9 9£ óBC99 4 cx 9¡ 5 c9¢9 9£ ¸í C9 F9µ9à9 # ,óBC£!eÖ 0¸ófC Fµ¶² ³ £j¼Õ g y § ²³ º 12. ÒÊ 3 Ëhºj»¼ 3 Ëh>ʹ 6 i§ £7Âj b (1) ¶Ëhʹ 6 i 6 (2) Æ9¶9Ë h99Ê9¹ 6 i 6 (3) 9à9Ë h99Ê9¹ 6 i 6 (4) k9È99à9Ë h99Ê9¹9Ú § i9¨ 6 (5) =99§ h99Ê9¹9Ú§ i¨6 (6) k9È9 9¶9Ë h99Ê9¹ 6 i9º 13. r 9è (r > 1) l m9 n o9£ ¸ píxõ9ö9£ ×9Ñ q9 Í89ðr9¯ ms t r − 1 9è99§ F9¶99º ¼ * u 9§ ²9³ b (1) m n Ñ9£ v9&$Bíxã9 6 (2) m n (n < r − 1) Ñ9£v99è w J9àÑ ( íxõ9ö9Ý q9 x y&jfw 1 Ñ ); (3) Æ n Ñ z&9íBm9¹9º 14. 3 999£jï9Æ j 99 #9 N x 9¡ M 9¢9 9£ j = 1, 2, 3. 9®9´9µ9¶99 9£j·9¸9 % #&$x¯²³ µà9 £`ÃĬ9¶y¶¢ºj»¼{à9 23ëÅxƶ£jÆ+ 9£jÆ99999§ º AºB19¸½9 15. ¶999 |9ë #9 N x 9¡ M 9¢9 9£ Ö } ~ 9¶99 £[ Ì % #&$x¯99®9µ9¹¶9 £`ÃÄ9¤¥gx º`»9¼}~ª ¬y § ²³ º 16. C999 m c9Ó 9Ï9Ð9£ n c9Ñ 9Ï9Ð (Ñ 9Ï9Ð9§9à9Ô9Í 9 ). ï C9 F9µ9¶ c9£ ¤
9Ê r Ñ9£j ×9Ñ ] º{c g g 17. ( ) A ] n B ] m n > m, ¡ ¢ £ ¤u ¥g8¦ r!§ ¨b© ª« A ¬ ® ¯ ° ± . 18. (² ) © x A ³ ´ µ ¶ · 19. ¸ ¹ 2n º » ¼ ½ ¿¾ ¼ ½ À Á  à p. ¼ Ä Å Æ Ç ¬ È É ¼ ½ Ê À Á Ë Ì À Á Í ¬  à n + m (0 ≤ m ≤ n) · 20. Î Ï Ð Ñ Ò ÔÓ ¾ Ñ ÕÖ ×Ø p Ù 1 − p Ú Ê Û Ü Ý Þ Û ·.ß ÑÒà á Æ n Û [¼ Ä â (1) Ó Ý ã ä å æ ç Ñ è n + 2i Õ é (2) Ó Ñ ê ë 0(Ý ã ) ä å ë N Û · 6.
1
1
2
2
1
1
2
2
1
2
n
j
n−m n+m
j
n
n
§2.5
ìîíðïòñîóîô
71
õ ö÷ø÷ù÷ú÷û ÷ üîýîþîÿ üîýîþ !#"$% &îü ýîþ ' ( ) * !,+-. /0123 4 îüîýîþ ! §2.5
56789:;< A = B ÿ?>? ???@?A (Ω, F, P B ?C?(?3?4?B ?D?E?F? P (A) G ÿH> !BI *JK/ L . EM (NO ! P (A|B); P (B) G P (B|A) P 2.5.1 QR ' 51 (>SBT 30 U 21 VWBRX 'YZ 17 [ BT 9 U !]\^_`a Rbc 1 [ ]def A = B gh a [ ÿ Ui= ÿYZ 34 ! 8V jklm n P (A) , P (B) , P (A|B) , P (B|A) . o n +- ' |Ω| = 51 , |A| = 30 , |B| = 17 , |AB| = 9 . p f §2.5.1
P (A) =
30 10 = , 51 17
P (B) =
30 10 = , 51 17
P (B) =
17 1 = , 51 3
P (A|B) =
17 1 = , 51 3
P (A|B) =
9 , 17
P (B|A) =
10 , 17
P (B|A) =
9 3 = . 30 10
Xqrstu v' P (A) 6= P (A|B) , P (B) 6= P (B|A). /wx* Dyz m B{4H|}{4 !B~ ÿ'N j M m Nn P 2.5.2 QR ' 51 (>ST 30 U 21 VWRX 'YZ 17 [ T 10 U !]\^_`a Rbc 1 [ ]def A = B gh a [ ÿ Ui= ÿYZ 34 ! 7V jklm n P (A) , P (B) , P (A|B) , P (B|A) . o n
' |Ω| = 51 , |A| = 30 , |B| = 17 , ~ ÿ' |AB| = 10 . "$ P (A) =
10 1 = . 30 3
X qrstu v' P (A) = P (A|B) , P (B) = P (B|A). /îÿ (
! / f 34 B iG &34 A i '34 ÿ &34 B i ' `- A “ üîý ”. A i
l u P (A) = P (A|B) , ¡ ' = P (A|B)P (B) = P (A)P (B) . ¡¢ s l u P (AB) = P (A)PP (AB) (B), P (A) = P (A|B) ,
P (B) = P (B|A) .
(2.5.1)
"$ (2.5.1) £ C(| £¤ >¥H ý ¤ >¥ ý !B+-§¦ X§q §¨© I
ªn l m
72
« ¬ ® ¯°±² ³ ´ 2.5.1 A = B ÿ> @A (Ω, F, P ) C(34 l u ' P (AB) = P (A)P (B) ,
(2.5.2)
µ¶ 34 A G 34 B üîýB· ¶ I üîý ! l Xp F A G B ü ý ¸¹ A º»¼½¾ B 9º»¿ÀÁÂÃÄ ! B º»¼½¾ A 9º»¿ÀÅÁÂÃÄ l uÇÆÉÈ§Ê E§Ë§M§ §M§Ì§Í§Î Ê §C§(§N§O§Bϧ'§Ð§} +§- ü ý þ§ §Ñ ª ! N 2.5.2 Ui = Ò R YZÓÔ , p f “ÿ I Ui ” & a i ÿ I Y§Z ” §§Õ þ§ §Ö§×§§'§§ ! w§ §B§N 2.5.1 É U§i É §Y§Z “ Ø N×}Ò R YZ Ø N "$ Ùv a i I Ui {4 m #ÚîÿYZ {4
Ï×}Ú ÿYZ {4 A * !ÜÝ ÖÞßàáÏTâ ã ! P (B|A) Û üîýîþ ªäåæ c m qt ! ³ç 2.5.1 A = B ÿ> @A (Ω, F, P ) C(34 µè 34 A G 34 B üîý¥ lmé &34 A üîýn (1) A G B ; (2) A G B ; (3)A G B . êë n P (A) = P (AB) + P (AB ), ì (2.5.2) £ B 1 3
c
c
C
c
c
$í g J A G B üîý ! T yzîïðJ !
ª 2.5.1 ÿ +- &}îüîýîþ p m ªòîÿóôC(34îÿ üîý X ñ
õö !÷ø è +- ` X ðJC(34 îüîý þ¥ ¡ùúûÈ ð J (2.5.2) £ Eü ! ìýþ a £ ý ÿ C(34 ¡ üîý ! P 2.5.3 A [0, 1) \^ (LBdef A = A gh a L A [0, ) = [ , ) 34 j B34 A G A ÿ üîý 0 §
}
§ ! å§ A A = [ , ), P (A A ) = P (A ) = o n /§
f (2.5.2) £ ý "$ A G A üîý ! P (A ) = . p è +- p fF “/0 } ”, ÿ "I “Lîÿ A [0, 1) ÿ \^ ”. % c ÿ ª 2.5.1 v 34 ü ý þ ÿ G @A
' ! NO +- p Ì@A Ω = [0, 1); 34 σ F
' Borel O P I Lebesgue !! ÿ/(@A p [0, 1) p q C(34 üîý #! "I & Ø +- ËEM m ñ NO ! P 2.5.4 Ì@A Ω = [0, 1); 34 σ F [0, 1) p ' Borel O ! &
$ O P (AB c ) = P (A) − P (AB) = P (A) − P (A)P (B) = P (A)(1 − P (B)) = P (A)P (B c ), c
1
1 3 4 4
1 2
1
1
2
[0, 1)
1 2
1
Borel
E,
2
1 1 4 2
2
2
%
P (E) = k:
X 1 2k
∈E
2
1 , 2k
1
2
1 4
1
ì íðïòñîóîô î 73 í 34 E |} E p '& l ' = ! H ( ð (Ω, F, P ) Kîÿ
(@A ! f A gh 34 [0, ), f A gh 34 [ , )( 34 σ
$ )Óîÿ34 ). j A G A ÿ üîý o n *+ £ +- ' P = , = + = . P (A ) = P 0, = ; P (A ) = P ~ ÿ' §2.5
1 2k
1 2
1
1
∞
1 2
1
k=2
`
1 3 4 4
2
2
1 2k
1 2
1 3 4 4
2
P (A1 A2 ) = P
1
1 4, 2
1 4
=
1 2
1 4
3 4
.
P (A A ) 6= P (A )P (A ) . H ý f (2.5.2) £ p A G A H üîý ! ,áâv +- f ûÈ Ì- þ.Eóô34 îü ýîþ0/1 f [ I _ ü ý þ 2 !,"I /yz m #f ` rs tu ÿ G34 5 )Eóôîüîýîþ )îþ ! P 2.5.5 6 798§[§§ ü ý _ é Û : ; <§
= >§ j§k §de n ? @BC [ c ñ ?' | ! o n/0B 678[ “üîý _ ” => è
îÿ ) ! f E gh 8[ c ñ ?' | 34 Ëdef A = B gA h v 6 = A 7 c k ? ñ 34 k = 0, 1, 2, · · · , n , å E = S A B , ìý è i 6= j ¥B3 4 A B G A B H B ' 1
1
2
1
2
2
k
n
k
k
k
k=0
i
i
j
j
P (E) =
n P
P (Ak Bk ) .
}C üîý _ => p f&C( k, 34 î [ > ÿ;<
p f P (A ) = P (B ) = C , ` k=0
k
P (E) =
n X k=0
P (Ak Bk ) =
k
n X k=0
Ak
G
Bk
Ó üîý ! }=
k 1 n 2n
P (Ak )P (Bk ) =
n X k=0
Cnk
1 2n
2
n = C2n
1 . 4n
/(Nv>¥ c * “ üîý ” = “ H B ” C(H> + - m D E c “ üîý ” = “ H ä ” /C( e ! P 2.5.6 A = B ÿ> @A (Ω, F, P ) v C(34 ý P (A)P (B) > µè 34 A G 34 B H ä¥ - ù H üîý W w è - üîý 0, ¥B ä ! êë n þ % - ” üîý ” è ýF è = P (A)P (B) > 0 ; - ” H ä ” è ýF Pè (AB) P (AB) = 0.
«¬ ®¯°±²
74
G6789:;< (34 îüîýîþîÿîH ýC(34 îüîýîþ IJ X ~ KL ! A , A , · · · , A ÿ> (@A (Ω, F, P ) n (34 l u - A + - ü' ý Tâv $ M d34 A ÿ è ÿ üîý ! f n = 3 I N §2.5.2
1
2
n
³ ´ 2.5.2 A , A , A ÿ > (@A üîý l u lm 4 (N £ Ó ý 1
2
(Ω, F, P )
3
3
(34 ¶ -
P (A1 A2 A3 ) = P (A1 )P (A2 )P (A3 ); P (A1 A2 ) = P (A1 )P (A2 ); P (A2 A3 ) = P (A2 )P (A3 ); P (A3 A1 ) = P (A3 )P (A1 ).
/0 è ýF è 4 (N £ ÓOPQÕF 3 (34 A , A , A üîý ! l u ' @ ñ 3 (N £ OP µ¶ 34 A , A , A 55:; . F ª üîý CCîüîý !~ DEFCCîüîýHÕRS X q üîý W ýT (| £ H Õæ c @ ñ 3 (| £ ! M UNO ! P 2.5.7 Ω = (0, 1); 3§4 σ F (0, 1) p ' Borel O W P I ! % Lebesgue 1
1
A1 =
1 0, 2
, A2 =
1 3 , 4 4
2
2
3
3
, A3 =
1 5 , 16 16
∪
9 13 , 16 16
.
jV 34 A , A , A ÿ üîý ! o n,å P (A ) = P (A ) = P (A ) = , P (A A ) = P (A A ) = P (A A ) = , ~ ÿ' P (A A A ) = 6= P (A )P (A )P (A ), p f34 A , A , A CCîüîý ~ H üîý ! A W§3§4 A , A > X §BË % A = ( , ).
j V §3§4 P 2.5.8 §§§@§
ÿ üîý ! A ,A ,A o n/(NO X,Y þB Z[ æ \ #! ]
B/0' P (A ) = P (A ) = P (A ) = , P (A A ) = , P (A A A ) = , P (A ∪ A ) = ~ ÿ' 1
2
3
1
1
2
2
3
1 2
3
1 16
1
2
1
1
1
p f
2
1
2
2
3
3
1
2
3
2
1 4
1
3
3 7 8 8
4
4
2
4
1 2
1
(3 34H üîý ! P (A A ) = $ +-^ BÌ' f X C(NO _` +- n 1
4
2
1 8
1 4
1
2
1 8
4
1
2
6= P (A1 )P (A4 ) . P ((A1 ∪ A2 )A4 ) =
3 8
= P (A1 ∪ A2 )P (A4 ).
3 4
,
ìîíðïòñîóîô 75 è ª 2.5.2 @ ñ 3 (N £ ý¥BH§ Õað T §( N £ (1) ý l N 2.5.7 ph ! w B ª 2.5.2 ] T (bbN £ H?ÕbRbSb@ ñ 3 (bbN £ ! 3 (2) õ§
§§Õ§' 3§X BN 2.5.8 ¡§g JÉ#ced§f§' §Pª (A A AÉ)
=f§P( (A )PN (A )P §(AH ), § ! ì§ý N £
£ g P (A A ) 6= P (A )P (A ). p 2.5.2 H HÕað 3 (34 üîý ý HÕa P (A A A ) = P (A )P (A )P (A ) F ð - CCîüîý ! N 2.5.8 ^ _` +- n íh 3 (34 A , A , A B' A G A ü (3) ý ìý A G A A üîý A G A ∪ A üîýBHÕað - üîý#/1HÕað - CCîüîý !Ba N A G A ¡ H üîý !B+- þ 'i i ¦j ª 2.5.2 f(N £ #Õklmn(34 üîýîþ ! /UNO g Jv#(34 A üîý þ' ¹op rqsS ùú &Ttu v ! m ñ +-w c n (34 îüîýîþª ! ³´ 2.5.3 A , A , · · · , A ÿ> (@A (Ω, F, P ) n (34 ¶ - üîý l u &$ x ' k, 2 ≤ k ≤ n, W$ x ' 1 ≤ j < j < ··· < j ≤ n , Ó' §2.5
1
1
4
1
2
1
4
2
4
1
4
4
1
2
4
1
4
2
1
2
4
1
2
2
1
2
2
4
1
4
1
n
1
2
k
P (Aj1 Aj2 · · · Ajk ) = P (Aj1 )P (Aj2 ) · · · P (Ajk ) .
(2.5.3)
è B X£ yz {* 2 − n − 1 (N £ ! ¡ ÿF n (34 ÿ
üîýîþ G / 2 − n − 1 (N £ >¥ ý|| !B÷ø § n (34 ü
ý R S§*§TÇ9$ M?d§3§4 § ü ý W ~ ÿ§w È E§ íbh TÇ9$
n − 1 3 4§Ó § ü ý§B§H§Õ a§ð n (B3§4§ x á X§§ ü ý ! §f } c & $
x ' T$ k (34Ó üîý ~ ÿ$ k + 1 (34ÓH üîý k, 1 < k < n
NO !
y & îï è 34 A , A , · · · , A üîý¥ ¦- $ G n=2
Md ¤ Òá ÷I ÿ &îý34@ p n (34 üîý ! +- w c 34 ~ îüîýîþª !
3 ³´ 2.5.4 A , A , · · · ÿ > ( @ A @ A (Ω, F, P ) ] b 4 ¶ - üîý l u & $ x ' n ≥ 2, T $ n (34Ó üîý ! /¥ +- 34~ {A , n ∈ N } ¶ Ia @A îüîý34~ ¤ üîý§3 4 ! å {A , n ∈ N } I üîý34 ~B| |}& $ x ' n ≥ 2, W$ x ' 1 ≤ j < j < · · · < j , Ó' n
n
1
1
2
n
2
n
n
1
2
n
P (Aj1 Aj2 · · · Ajn ) = P (Aj1 )P (Aj2 ) · · · P (Ajn ) .
«¬ ®¯°±²
76
+- E w c üîý34~ (NO ! P 2.5.9 §§§@§A l >§N 2.5.7, í Ω = (0, 1); 3§4 σ F (0, 1) p ' Borel
O W P I Lebesgue ! ˧ 0 < p < 1. & $
x ' n, a = 0 ,a =1, ì a =p; n, 2n
n, 0
1,1
a2,1 = p a1,1 = p2 ,
Ùª a)
2,3
= a1,1 + p (a1,2 − a1,1 ) = a1,1 + p(1 − p) = p(2 − p) ;
+- Ë ä å a M c l =ua % q, = a1−p, d Ø I C(× +- ª k+1,2m
a2,2 = a1,1 = p ,
k,m
ak,1 , ak,2 , · · · , ak,2k −1 ,
=
a I A (a
k+1,2m−1
p q
An =
L Ó ¦ A ) = (a
+ p (ak,m − ak,m−1 ) , m = 1, 2, · · · , 2k .
k,m−1
x = ak+1,2m−1
k+1,2m−2 , ak+1,2m−1
2n−1 [−1
(an,2m , an,2m+1 ) ,
(ak,m−1 , ak,m )
k+1,2m−1 , ak+1,2m ).
n = 1, 2, · · · .
} ÿ {A , n ∈ N } ÿ A (0, 1) v Î è
ÿ +- p @Aâv 34 ! fðJò&$ x ' n, Ó' P (A ) = p , ìý & &$ x ' n ≥ 2 = $ x ' 1 ≤ j < j < · · · < j , Ó' m=0
n
n
1
p f
2
n
ÿ (îüîý34~ !
P (Aj1 Aj2 · · · Ajn ) = pn = P (Aj1 )P (Aj2 ) · · · P (Ajn ) ,
{An , n ∈ N }
: ;9¿À cd&34 ü ý þ ùú u ¢ u ~ ÿ&} ü ý34 rs '+ /fFîÿîüîýîþ Cîþ 34 [ )§
þ §§f û§È§r§s§t§u§G 3 4 y ¦ ü ý þ "§I §§§ ! /§§§§
û
z 5 ) E (! è A , A , · · · , A ÿ> (@A (Ω, F, P ) n ( üîý 34¥ f· I §2.5.3
1
2
n
P
µ · I
n \
k=1
P
n [
k=1
Ak
!
Ak
!
=
=1−
n Y
P (Ak ) ,
k=1
n Y
k=1
(1 − P (Ak )) .
(2.5.4)
ì íðïòñîóîô î 77 · ü ý þ ª ! · £ æ lm n 34 A , A , · · · , A ü ý 34 A , A , · · · , A ü ý Ë De Morgan µ §2.5
1
2
n [
P
c 1
n
Ak
k=1
!
= 1−P
n \
Ack
k=1
!
=1−
c 2
n Y
k=1
c n
P (Ack ) = 1 −
n Y
k=1
(1 − P (Ak )) .
m ñ +- E12 rs U,á NO ! þ§§ ÿ ¡N ¢ ¤ N ¢§
£§4 ¤ " §§§§§ §&ÿ ÿ § §§ § §(§§ §d ¥ ! § þ§§ÇÉ ¦ £§4 ¤ " §§ ¶ I £§4§ þ ¦ N¢ ¤ " ¶ I N¢ îþ ! ìý Dyz m û N¢ é ( £4 ¤ " 34 Aîÿ üîý ! P 2.5.10 lmé N¢âv é ( £4 ¤ " 34 A üîý ìý ( £4 îþ I p , jké N¢ îþ ! T k k
¦§¨©ª
o ¬n «N¢ 1 ® £ 4 1 ¯ n °±® £ 4 ì"±³ ²3f4 Eåg h N¢ 1 ¤ " ³ 34 ® f ® (
2.1)
1
X q C ° £4 ¯ 2n ° ± ® = A d e gh C ° £ 4 ¤
n+1 A1
2
P (E1 ) = P (A1 ∪ A2 ) = P (A1 ) + P (A2 ) − P (A1 A2 ) =
n Y
pk +
k=1
2n Y
k=n+1
pk −
2n Y
pk .
k=1
«N¢ 2 s ® £4 k G n + k ì±® k = 1, 2, · · · , n. Xq n ´ì± °±² f N¢ 2 "³ 34 ® f A gh £4 j ¤ "³ 34 ® j = 1, 2, · · · , 2n. E gh ¤ å 2
j
P (E2 ) = P
f
n \
k=1
(Ak ∪ An+k )
!
=
n Y
k=1
P (Ak ∪ An+k ) =
n Y
k=1
(pk + pn+k − pk pn+k ).
" ³ 3 4 ® g h Ë Nbf ¢ 3 b¤ "b£³4 3 4 1 ® f A ³ g Oh N£ ¢ 4 k "b ³ ¤ 3b 4 ® f B k = 1, 2, · · · , 6 . B gh 1 4 ¤ gh £4 5 = 6 ³ ON¢ ¤ "³ 34 ² å E3
k
1
2
P (B1 ) = P (A1 (A2 A3 ∪ A4 )) = p1 (p2 p3 + p4 − p2 p3 p4 ) , P (B2 ) = P (A5 A6 ) = p5 p6 ,
³ µ [ ¶ £ í ² · E ¸b¹ Nb¢ 4 b¤ "b³bºb» ® · k = 1, 2, · · · , 5 . ¼½¾
Ë ¦
P (E3 ) = P (B1 ∪ B2 ) = P (B1 ) + P (B2 ) − P (B1 B2 ) = P (B1 ) + P (B2 ) − P (B1 )P (B2 ) , P (B1 ) 4
=
P (B2 )
Ak
¸b¹ £ »
k
b¤ "b³bºb» ®
¿ÀÁ
78
ÂÃÄÅÆ
P (E ) = P (A )P (E |A ) + P (A )P (E |A ) . ¢ ¢ 2 n = 2 ³ÎÏ ®#ÐÑ A ÇÈÉ ®#Ê 4 ËÌÍÊ ³2 +ÎpÏ −®#pÐpÑ ) . Ò « A ÇÈÉ ®#Ê P ¢ (E 4|AË)Ì=Í(pÊ ¢ + p1 − pn p=)(p
«
4
5
4
c 5
5
c 5
4
5
4
5
1
3
1 3
2
4
2 4
c 5
µ×
P (E4 |Ac5 ) = p1 p2 + p3 p4 − p1 p2 p3 p4 .
¶ÓÔÕÖ
P (A5 ) = p5 , P (Ac5 ) = 1 − p5
P (E4 )
³ ¸Ø ÕÙÚ ²
Û Ü 2.5 1. ÝQÞQßQàQáQßQâQáQãQäQåQæQçQèêéQëQìQèêíQî 3 ïQáQðQçQñQòQóQèêôQõQöQïQ÷QøQùQúQûQüQý E = {þQñQòQÿQî 1 ïQâQá }, F = {ñQòQóQîQàQáQî!â!á }. ô!î 2 ï!á!ð!ç ñQò 2. Q÷Qø A B ûQüQ è QöQ÷QøQó A Qß B QßQè B Qß A QßQç Qã . P (A)
1 4
P (B).
QïQ÷Qø A, B, C ûQüQè¬ëQì A ∪ B, A − B C ûQü ö ç ð è A = {!"# }, B = {$%"# }, C = {$&" ëQìQý¬÷Qø A, B, C öQöQûQü'(Q) û!ü 5. í*+ 2.3.21 óQè, A = { $ i ï-.Q / í0Q1 ð23 }, ëQì A , · · · , A ùQúQûQü 6. ë ì ý ÷ ø A , · · · , A ù ú û ü ç4567Q 8 ø ãQý:9; ï Aˆ = A < A (k = 1, · · · , n), Qî 3.
4.
i
1
1
n
k
n
c k
k
ˆ1 · · · A ˆn ) = P ( A ˆ1 ) · · · P ( A ˆn ). P (A
ëQìQý¬ô P (A|B) = P (A|B ), =Q÷Qø A B ûQü
Q÷Qø A >?0ûQüQè¬ëQì P (A) ä@ 0 < 1. 9. Q÷Qø A B ûQüQè, P (A ∪ B) = 1, ëQì A ABQ÷QøQûQü 10. 9CDEFGQûQü! ç HI!,è $%GHI!ç J!ó" 0.4, $&G" 0.5, $G" 0.7. C D K ! I ó % G L M ! N ç " 0.2, I!ó &GLMN!ç " 0.6, OKI!óG=CD6 P MNQ,è HIGL INCD! ç 11. Ý ;Qï QRSQó TUVWXQç " 0.004, YQï QRSQã ZTUVWXQùQúQûQü [ 100 ï QRS\]2TUVWX!ç 12. ^_ `bac/deac n ï fbg ÝQÞQí achi!ó $ i ï fbgjkQç " p , Y f gQã ZjkQùQúQûQ ü lQõ mQ÷!ø!ç Qý 1) achiQó nQ î fbgjko 2) ÿ p%Q ï f gjko 3) @%Q ï fbgjk 13. qrs K t rQè < rs K K uvt r v `bw t rx K , K , K t rQ ç yG ã 0.4, 0.5, 0.7, YrsQùQúQûQü ,z`{w t rQç 14. | 3 Q ç QðQè ÷Qø A }~$%Qè &Qö Qð Qù u ç Qè ÷Qø B }~$&Qè $ ð !ù u ç !è ÷ ø C }~$%!,è $ ð !ù u ç ¬é !÷ ø A, B, C ã Z"Qý (1) öQöQûQü o (2) ()QûQ ü 15. Q÷Qø A, B, C ()QûQüQ è
Qç !ä @ 0 ! 1. é Q÷Qø AB, BC ! AC æ Z"Qý (1) öQöQûQ ü o (2) ()QûQ ü 16. Q÷Qø A, B, C öQöQûQüQ è
Qç !ä @ 0 ! 1. é Q÷Qø AB, BC ! AC æ ü o (2) ()QûQ ü Z"Qý (1) öQöQûQ 17. A B "QùQúQûQüQ÷QøQ è LQ÷Qø C Q÷Qø AB ! A ∪ B QûQü é Qè ÷Qø A, B, C c
7.
8.
i
1
2
3
1
2
3
}.
§2.5
79
ãZ%QÞQöQöQûQüz
A, B, C, D "Q÷QøQè, A ! B C ! D ûQü¬ëQìQý¬ô AB = φ = A ∪ B C ∪ D ûQ ü 19. A, B, C "Q÷QøQ{ è 0Qó A ûQü@ BC ! B ∪ C, B ûQü@ AC, L C ûQü@ P (A),P (B) ! P (C) "¬ëQìQè¬÷Qø A, B, C ()QûQü 20. ëQìQ è A , A , A çQöQöQûQü %QÞ!æ
!ç!ù!ú!ûQü 21. ëQìQ è 0ä 18.
1
Qæ
2
3
P (A1 A2 A3 ) = P (A1 )P (A2 )P (A3 )
Qç öQöQûQü 22. ÝQÞQ÷Qø A, B, C öQöQûQüQè, A1 , A2 , A3
ABC = φ,
éQë
x
ç"
1 . 2
P (A) = P (B) = P (C) = x.
CD = φ, AB,
¡
¢ £¤¥¦§¨©×ª¦«¬ ¶ ¨¯° º»±²³´ ªµ 19 ¶·¸¹ Ç ® º¼»¾½À¿ÀÁ ¨ÀÂÀÃÀÄÀÅÀÆÀ© ×À¨ÀÇ ÈÀÉÀ¦À§À¨À© ×ÀÊÀËÀÌÀ¦À«À¬¼Í¾ÎÀÏÀÐÀÑÀÒÀÓ ÔÕ¨Ö× ±ÙØ ¢£¤¥¦§¨ÚÛÜ Ó ÇÙݪ 20 ¶· 30 Þ ÔÇÙµ¦«¬¨ßà Õâá Êâãâäâåâæâç à åâèâé ¨ ±bØ Íâêëâìí Åâî¦â«¬â¨ïâÇ{ðâñ Ìâòóâôõö ÷ ó ÚÛøù ö Ô ëúûüý ¢£¤¥¨¦§ ±
þ ÿ
§3.1
¢£¤¥¨ ôõ ¦§ Í ¢£ ì Ç ´ ó É¢£ ì ± 3.1.1 ¾ n ë 1 ë ±"! ó É ë É ë#$% Ç ô Ñ $%../&' Ü.Ç0.(*.)+ *¨ +¨ $,Ç2- 1.± â3 Ç ¨.4 ¢ £.5 Ò.6 Ç ²Ú.7 ª ξ $.= .Ò,.> - Ç<?ξ@ Ø {1, 2, · · · , n+ ¨ 9 : É 4 < ± ; 1} 8 ë êë k ∈ {1, 2, · · · , n + 1}, ð 7A Í B % ¦« P (ξ = k) ± I ¢£JK ç 7 B %L ¦«4 ±HMN (ξ = k) OP ª óCDE ÑF ÇHG Q ªÀ¢À£RJRKRSUTVJRW ö ÇR Ú å ! ÈRKRJ Î ¤ & É F RR*RXRYÀ¨À¢À£ ìR ZU[]\ ^ I n ë^<R 1 ëRR ±! À óR^ É ë É ëR$R% À Ç ì B ô Ñ C k ,$_ É/Çç$*ÑXY ¨ ¨¦«Ç Ú ± Èabc È Z\ Ñ ` å ëd å A Ü0 ô Ñ C k ,$ Õ ÉB Çà ç$ Ñ ¨JK Ç å Ω Ü0 k ,$ ¨*I Ú7ef ± Í ª Ú »ghi |Ω| = (n + 1)n(n − 1) · · · (n − k + 2), |A | = n(n − 1)(n − 2) · · · (n − k + 2), l ¨¦«ß Õ Ã Ò ó »jk ¦ §3.1.1
k
k
;m % (ξ = k) L WnPª(AJ)K = A , o=p nI . q øÑ*è efØ 9 : k Pð(ξr=/ k)Ç =Ð PI (A ) = Ç
k
|Ak | |Ω|
1 n+1
k
k
stuI
P (ξ = k) =
1 n+1
.
1 , k = 1, 2, · · · , n + 1 . n+1
n+1 P
P (ξ = k) = 1 .
k=1
80
(3.1.1)
v wxyz{ 81 |~} ö Ó b~câÇ~ ÑâÒâÉ ë “¤â¥ ”ξ, ² ¨~4â¢â£~5 Ò~6 Ç ² * Ú~7 $ ¨~4 ¨~~âª~ 6 ¨ ± Ì~ ~ & I~~ Ç Ø Í~ ~ ¨ êâë 4 a , ð 7~! (ξ = a )
Õ &RÀ ë ¢À£ ìR^ ¨ÀÉ ë JRKÀÇÉ sRt _ / jRk ¦RlRB % ¦À« P (ξ = a ) ¨R4 ± (3.1.1) Õ n % Ò 3.1.1 ¨ “¤¥ ”ξ ¨ $ 4 ξ $ ë 4 ¨¦«Ç*IȦ«4¨ Í 1. ! (3.1.1) Õ & ¤¥ ξ ¨ ± 3.1.2 ^ I a ë^<R b ëRR ± óR^<R^<#$% n ëR Ç L^ () $% ¨ ¨ - Ù[ ± n ≤ min(a, b). / ξ ÜR0 $R% ¨ ^ ¨ <R- [ Ç1R3 ξ ¨R4RuÀªÀ¢À£R5 ÒR6 ¨ÀÇ ² ÚR7 ª {0, 1, · · · , a} 8^ ¨R9RÀ : É ë 4 ± sRÀt Ç Ø ÍÀêÀë k ∈ {0, 1, · · · , a}, RÀ ð Ú å ! (ξ = k)
Õ & É ë ¢£ ì ¨É ë ¢£JK \ I a ë b ë ± ó#$% n ë Ç L n ≤ min(a, b), ì B* $% ¨ I k ë §3.1
k
k
k
¨¦« ±
Ü 0* $% ¨ 娦A« ± JW ö ÇI k
Ak
I k ë ¨ JKÇ]/ jk ¦ l i
P (Ak ) =
C k · C n−k |Ak | = a nb . |Ω| Ca+b
1 3Ç (ξ = k) JW ö nªÈ¨¢£JK ªÃÑ \ P (ξ = k) =
stI
a X
Ç /ÑÒ
µ ö Ó
a P
st
åö
a P
k=0
Cak · Cbn−k n Ca+b
=
;m B %
bc Ø 9 : k ð r/Ç
Cak · Cbn−k , k = 0, 1, · · · a . n Ca+b
P (ξ = k) =
k=0
Ak ,
Õ Ç
Í
(3.1.2)
n Ca+b =1. n Ca+b
ÈÉ Õ± Èa Ã Ñ Ò É ë “¤ ¥ ”ξ, ² ¨4 ¢ £5 Ò6 Ç ² * Ú7 $ ¨4 ¨ ÀªÀÉ ë 6 ¨ » IR ëRRR-RÀé ¨RRÀÇ ØR R ¨ êÀë 4 a , ð 7 ! (ξ = a )
Õ &ë ¢£ ì ¨ÀÉ ë JRKÇ¡sB % ¦À« P (ξ = a ) ¨4 ± Õ n % ÒÈ ë “¤¥ ”ξ ¨ $ 4 ξ $ ë 4¨¦«Ç*I (3.1.2) È ¦« 4¨ 1. op (3.1.2) Õ nªÈ ë ¤¥ ξ ¨ ± ! 3.1.1 ¢£ ¤ÕÇ ÃѤ ¸d Z\ 3.1.3 I n ë 1 ë ± ê,ó$% É ë Ç"s ×É ë Ç ô Ñ $%&' Ç ()*+¨ $,- ± k=0
n Cak · Cbn−k = Ca+b
k
k
k
¥¦§ xyz{ / ξ Ü.0.*.+ ¨ $..,.- Ç21.3 ξ ¨.4.u ª ¢ £.5 Ò.6 ¨ Ç ²Ú~7 ª {1, 2, · · ·} 8ðâªâ ɨ9¢â:£~É J~ë Kâ4 Ç (²I ¨âÚ ¦âh «ë ð~Úu7 ª 4 Ú). ¨ B ª Ø ± êë k~∈ {1,Ú 2, ·! · ·}È,K~(ξJ=ªâk)¤ © ¢3 ë å % o~& å & £ ì Z[«\ I n ë 1 ë ± ê,ó$% É ë Çs ×ÀÉ ë Ç ì B ô Ñ C k ,$¬ Ç ç$ Ñ ¨¦« ± Ø. È ë ¢ £ ì. Z[ Ç®. Ú b~c.¤ ¸ \ å A Ü.0 ô Ñ C k ,.$..¬ Ç ç.$ Ñ ~Ò¨~° J~I KâÇ å Ω Ü~0 k ,~$~ ¨~*~I Ú~7~e~âf ±¯ ª |Ω| = (n+1) , |A | = n , ó 82
k
k
P (Ak ) =
åö
|Ak | nk−1 1 = = |Ω| (n + 1)k n+1
bc Ø 9 : k ð r/Ç ª ÃÑ \
stI
1 P (ξ = k) = n+1 ∞ X
P (ξ = k) =
1 1− n+1
k−1
1−
1 n+1
k−1
k
k−1
.
, k = 1, 2, · · · .
(3.1.3)
k ∞ 1 X 1 1− =1. n+1 n+1
È aÃÑÒÉ ë “¤¥ ”ξ, ² ¨4¢£5 Ò6 Ç ; } ² * Ú7 $ ¨4¨ RÀªÀÉ ë 6 ¨ Ú h ±±³² ¤ p Ç ØR R ¨ êÀë 4 a , RRuÀª 7R!
Õ &ë ¢£ ì ¨É ë JKÇ´B % ¦« P (ξ = a ) ¨4 ± (3.1.3) (ξ = a ) µ n % ÒÈ ë “¤¥ ”ξ ¨ $ 4 ξ $ ë 4¨¦«Ç*IȦ «4¨ 1. op (3.1.3) µ nªÈ ë ¤¥ ξ ¨ ± ¶ É ë · ± 3.1.4 ¸¹º [0, 1] ¢£ »¼É ë½¾ Ç() ½¾ *¿ÀÁ¨ÂÊ ± / ξ ~Ü 0 ½~¾ *~¿~À~Áâ~¨ ÂâÊ ± 1~3 ξ ~¨ 4~uâªâ¢â£~5~à 6 ¨âÇ ²~Ä7 $ à ¹ ºðI [0, 1] ¨ 9:É ë 4 (I B ;Ä h ÅÆë Ä7 4 ).ÜÇ0 È% ¿Ç µ Ø 9: x ∈ [0, 1],Ç * å Ä P å(ξ _ = /x)É=:0.¦ l % P (ξ < x). o& (ξ < x) ½¾ ¹º [0, x) k=1
k=0
k
k
k
IʨªÇ Ø x < 0 , (ξ < x) Ü0 ½¾ ¿µÂÊË ¾ åRÌ Ç ÈÀµRÀ¨ d Z ª ;Ä7 Ç* å ÃÍ x > 1, Ý » µ ¨ Pd (ξZ < x)Ç =½0¾ , *x¿Î<À0.Á ¨Â Ê É 6 ; ° 1, * å É 6Ï W ÓÇ ó à ² ªÐ3JKÇÑà (ξ < x) P (ξ < x) =
L([0,x)) L([0,1])
=x,
P (ξ < x) = 1 ,
x ∈ [0, 1].
x > 1.
v wxyz{ ÈaÇÒ Ø 9: §3.1
x∈R,
ðB
%
Ò¦«
0, P (ξ < x) = x, 1,
P (ξ < x)
¨4ÇÓI
83 (
ÔÕí
3.1)
x < 0; (3.1.4)
0 ≤ x ≤ 1; x > 1.
Ö × 1Ç (3.1.4) µ ;Ø % Ò ξ È ë ¢£5à 6 ¨¥¨ $ 4ÇÃt % Ò ² $Ù ;Ú 4¨¦« ± JW ö Ç _ / µ ;Ø ° F ¦À« P (ξ < x) ¨4Ç Ãtu Ä å B %L ² Ù ¦«4 ± ¤ \ P (a ≤ x < b) = P (ξ < b) − P (ξ < a) = b − a ,
ÇÛ
P (ξ ≥ a) = 1 − P (ξ < a) = 1 − a ,
±
0 ≤ a < b ≤ 1,
0 ≤ a ≤ 1,
& p F (x) = P (ξ < x) , x ∈ R, s t ! F (x) ÜÝ ¤¥ ξ ¨ßÞàáâ . ;m % Ç Ø 3.1.1 ¨¥ ξ, Iãñ¨ä F (x) = P (ξ < x) =
Ø
¨¥
3.1.3
F (x) = P (ξ < x) =
F (x):
x ≤ 1;
P (ξ < 1) = 0, k n+1 ,
P (ξ ≤ k) = k < x ≤ k + 1; k = 1, 2, · · · , n + 1 ; P (ξ ≤ n + 1) = 1, x > n + 1.
ξ,
ÝI
x ≤ 1;
P (ξ < 1) = 0, k P
P (ξ = m) = 1 − (1 −
1 k n+1 )
, k < x ≤ k + 1; k = 1, 2, · · · .
å 3 Iãñ¨ä - F (x), æç ;m èé % ± ¤ öRêÀë R· * % ÓÀ¨À¤À¥ ξ n Ü<ÝëRR R . ØR ¢À£À¤À¥ÀÇRUì]í Ä åîï ¤ ¸ \ ¢À£À¤À¥ ξ ªÀ¢À£ ìR ¨ eRf Ç ²Rð IRñ ëRòRó \ (1) ξ ¨R4À¢À£R5Rà 6Rô I × ¨ $ 4 ô (3) Ø 9:W - x, (ξ < x) 𪢣JKÇ op Ç ²ð (2) ξ IÀÉ ë RRä - F (x) = P (ξ < x), x ∈ R , ä -RîRï ÒÀ¢À£À¤À¥ ξ $RRÙ ; Ú 4¨¦« ± Ø G $õÆ Ä h ë 4 ¨¢£¤¥ ξ, Ý Ø ² * Ä7 $ ¨ ê É ë 4 𪢣J K Ç op Ç ²ð I É ë Ç » ² ¨ Ä Ã ² ¨ a, (ξ = a) ä - ± Ä åö%÷÷ÆÆ ¢À£À¤¥À¨R·R ÇR¤ \ 110 øùú µÉû *ü Ѩ øù,- ξ; ïýþ 10 ÿ *ý ¨ - ξ; ¼ · É , *¼ % ¨ ¾- ξ; ÉG * % G - ξ; É ë ï ξ; ëé ï æ ξ; # É , Ø
(3.1.5)
3.1.2
¨¥
ξ,
m=1
¥¦§ xyz{
84
!" ξ; !#$% ξ; û RÈ ξ; û ξ;
&'() ξ; ****+ ,- Ã./1023 45 6 $%7 Ï89 /1: õ45 ;6<=?>è/1@ ð ACBCDCECF +HGCICJ ACKCDCLCMCNCO 4CPCQCRCSCTCU /HVCWCXCY CZC[C\CTCU^] _ +1`abcde /1fDgh023 ijkl /1mn 4PQ;op;qr Mst + u vwxyz{|}~uv ;q ; ;p;;
;;; ;/;"; M ;$;A~ü + ( ), A ⊂ X . §3.1.2
IA (x) =
(
0, x ∈ Ac
.
¡¢£ A q / ¤¥ ¦ d
§ I . (Ω,F,®PF) ©E O kª / A ∈ F(« A 02¬ ),
Ω ¯° 0 \ 1 ± )2· ® +H`¬a ¸ξO=/HI¹ A )UC² ¬ 0 µ 0, °´5 A ¶ ), ÿ (G¶d) Q
IA (x)
¨
ξ =1 I³ ¡ A
A
A
(
ξ(ω) = IA (ω) =
« A
x∈A
1,
1,
ω∈A
0, ω ∈ Ac
,
P (A) = p, 0 < p < 1,
c
P (A ) = 1 − p := q,
º«
ξ = IA
PQ @02¬
C GCIC¡ A » A¼½¾¿
P (ξ = 1) = P (A) = p, P (ξ = 0) =
!
(3.1.6)
(ξ = 1) = {ω|ξ(ω) = 1} = A, (ξ = 0) = {ω|ξ(ω) = 0} = Ac ,
+HC
0 1 q
p
À 023 jÄÅ /H P I Á  ξ = I »Ã » A ¼½¾ (3.1.6) 023 Bernoulli 023 È En 4 ©É¬ A, @A A + A = Ω, GI ¹ A
c
023 + ¹ QÆÇp + Q A
IA + IAc = 1.
(3.1.7)
ÇA G ;Ê ω @ ¯;Ë;Ì;5 A \ A Í H/ (`;A a; ® Ì;5;Î;Ï Í ). c ω ∈ A ©Ð É/ = 1, I (ω) = 0; ¶c ω ∈ A Ð I (ω) = 1, I (ω) = 0. 4 @ω I A (ω)(3.1.7) W ÑÒ + c
A
X
Ac
c
Ac
A
ÓÔÕÖ×Ø ©E ± ¸/ ¹ Q a\ b 23 / P¯° a \ b ± ) / « A §3.1
(
a,
a
b
p
q
!
ξ(ω) = IA (ω) =
P (A) = p, 0 < p < 1,
ξ = aIA + bIAc ,
ω∈A
b,
P ¼½¾ ¡
ω ∈ Ac
ξ
¡Ù 0
85
.
.
(3.1.8)
¹ QCÆCÇCp ¼C½C¾ (3.1.8) ±CÚ ¼C½ +HGCI Bernoulli 0C2C3 CÛCL ÄCÜC ¼½ 023 + 0,1 ±Ú ¹ Q³¥ Æ Ot kl ¤Ý ¿ kª (Ω, F, P ) Þ Aß ¼à («á à ¬â ){A , · · · , A }, PQ » A kª P (A ) = p , k = 1, · · · , n, ã a , · · · , a n ¸/H P ξ = a I +···+a I = a I ¡ ;®;F;;ä k;ª ;O ¥ ° a , · · · , a Ç n ,å ); 0;2;3 ;+ ¬;¸ O/ c ω ∈ A Ð /HA ξ(ω) = a , k = 1, · · · , n. GI / ξ ¼½¾¿ Iæç A P p = 1. P (ξ = a ) = p , k = 1, · · · , n. ¬âR è /Hé A kª (Ω, F, P ) Þ ¥ê ¼à («¥ê á à ){A , A , · · ·}, « S A ∩ A = Φ, i 6= j; A = Ω, PQ » A kª P (A ) = p , k = 1, 2, · · ·, ã a , a · · · ¥ê ¸/H 1
1
n
k
n
k
n
1 A1
n An
k Ak
k=1
1
Ak
n
k
k
n
k
k
k=1
1
2
i
∞
j
k
k=1
k
k
ξ=
∞ P
1
2
a k I Ak
®Fä kª CCO C¥ ° a , a · · · Ç¥ê ,Cå ) 023 C+ ¬ ¡¸O / c ω ∈ A Ð /HA ξ(ω) = a , k = 1, 2, · · ·. GI / ξ ¼½¾¿ Iæç A P p = 1. P (ξ = a ) = p , k = 1, 2, · · · . ļìëìí /A ì ì kìª ì (Ω, F, P ) îÞì ìAì;ß ; 0;¼ì2;à 3 {A , A · · · , A }, P;Q ë » k;ª P (A ) = , k = 1, 2, · · · , n + 1, ξ = P kI ¡ »¼CAà (3.1.1) ¼½¼ ¾ +ï¶A kª (Ω, F, P ) Þ ¥ê {A , A , · · ·}, PCQ ë » kCª P (A ) = 1 − , k = 1, 2, · · · , 023 ξ = P kI ¡ » A (3.1.3) ¼½¾ + 6ð í /H¹ QÙ¥ ñ còkª Oó 023 ô Í » A (3.1.2) ò ¼½¾ + k=1
k
∞
1
2
k
k
k
k
k=1
1
1 n+1
k
1
2
k=1
Ak
n+1
Ak
k=1
k
∞
2 n+1
1 n+1
1 n+1
k−1
õ ö÷ ÕÖ×Ø "ù$ È En/ú¹ QÇû °òkª (Ω, F, P ) ù$üA , ø å + ¹ QýþÆkª ü02ÿ / Ω Y c 02 ÿ òj¥Ëò / `a J / Ω ¡ À02ÿ òj¥Ëò y kª / » / O Ò ¶ ¹ ¨ / C¹ DQCCXC Y (Ω, F, PC) ÞCCD ò ¼Cà «C¥C+HÇ , Ë ò C [ C Q ¯ C ò C k ª , C¹ Q 4CkCª C ò
1
1
A1
2
2
A2
1
1
2
A2
2
ω ∈ Ac1 Ac2 ; 0, ξ(ω) = ξ1 (ω) + ξ2 (ω) = 1, ω ∈ A1 Ac2 ∪ Ac1 A2 ; 2, ω ∈ A 1 A2 .
¼½P ¾(A ) ¿ = p , j = 1, 2, `a§ ò
A1
j
qj = 1 − pj ,
j
0 q1 q2
1 p 1 q2 + q 2 p 1
XDEW ò Bernoulli 023 Í \ I J p 023 + ¹ Q'ÂÁ NO + P 3.1.5 QRSTU 3 V /H ξ W /H¹ Q KY¦ Ω +Z ¿ / X / X ), (X / X / # ), Ω = {(X / # / # ), (# / X / # ), (# (X
2 p1 p2
¹ Q ,KL
!
(3.1.9)
ξ = ξ 1 + ξ2
.
(3.1.10)
/ú¹ Q¥ ó M ¹ Q fD òo d ò X ò ¨ V + / # / X ), (# / X / X ), (X / # / X ), (# / # / # ) }
ÓÔÕÖ×Ø ¹ Q ¦ d
§ Ω := {ω |j = 1, 2, · · · , 8}. O / æ ç ξ o ,å[ Ú ò ) ¼ ë §3.1
87
j
ξ(ω1 ) = 3;
ξ(ω2 ) = ξ(ω3 ) = ξ(ω4 ) = 2;
TU \] ò / äN òkª
ξ(ω5 ) = ξ(ω6 ) = ξ(ω7 ) = 2;
L ,
P (ξ = 3) = P ({ω1 }) =
1 ; 8
^_` ò b/ a ¶ cd
ξ(ω8 ) = 0. {Ω, F, P }
3 ; 8 1 P (ξ = 0) = P ({ω8 }) = . 8
P (ξ = 2) = P ({ω | ξ(ω) = 2}) = P ({ω2 , ω3 , ω4 }) =
P (ξ = 1) = P ({ω | ξ(ω) = 1}) = P ({ω5 , ω6 , ω7 }) =
3 ; 8
e; ; *T*U , *\*] ò / ; ÀO;t k;ª ; ¡ , c*d ξ ò ¼;½;¾*f + eg [TU µ\]/H¹ Q @ ¥ J ¨ òh _i ´+ ÞQjXXòDkEªW 0p,2(0¬< p < 1). ¹ Q + ° kª @ {Ω, F,N P },/ ô, d N ò A , A , A , PQò kª p( ¥ + 1 _ 23 2.5.9 òh ° ). ç 1
ξ k = I Ak ,
5 ¡ A
2
3
ξ=
3 X
ξk ,
k=1
0, ω ∈ Ac1 Ac2 Ac3 ; 3 1, ω ∈ A Ac Ac ∪ Ac A Ac ∪ Ac Ac A ; X 1 2 3 1 2 3 1 2 3 ξ(ω) = ξk (ω) = 2, ω ∈ A1 A2 Ac3 ∪ Ac1 A2 A3 ∪ A1 Ac2 A3 ; k=1 3, ω ∈ A 1 A2 A3 .
`a¥ W « À I L ,
ξ
ò ¼½¾ (§ 0 q
1
3
3pq 2
(3.1.11)
q = 1 − p): ! 2 3 . 3p2 q p3
(3.1.12)
k l 3.1 1. m A n B oqpqrqsqtquqvqwqxqyqzqsq{q|q}q~q (1) I = (I −I ) ; (2) I = |I − I |; (3) I = max{I , I }; (4) I = min{I , I }; (5) I =I ·I . 2. C
tu (1) f (k) = , k = 1, 2, · · · , N ; (2) f (k) = C , k = 1, 2, · · · , λ > 0. 3. x a sn b s!{|xr y¡¢£ 1, ¤¢£ 0. ¥ ¦
y{|§¨©ª«¬xy¡®°¯ A∆B
A
B
A∪B
C N
A
B
A∩B
λk k!
A
B
A
B
2
A∩B
A∆B
A
B
88
õ ö÷ ÕÖ×Ø {|§¨¶· ξ y
m{|}~ A, B ±²³´µ a < b, ξ = aI + bI ¬ 5. ¦¸s n ≥ 1, ξ ¹ o{|§¨ sup ξ , inf ξ , lim sup ξ , lim inf ξ º {|§¨¬ 6. x 5 sp»¼y½¾¼ 1, 2, 3, 4, 5, x¿ÀsÁ ξ Âà yx yÄžº¼ÈÉ·ÊËξ Ì y«¬ 7. ÆrÇ zÎÍ ξ ÂÃzÏÐnÎÍ η ÂÃzx½yÏÎÑ· ξ n η y«¬ 8. 15 ~p»¼yÒ~xÓz~Ô¬ÖÕ²×!ØÚÙÖÀÖ¸r~ÖÍ ξ Âà Ôy~· ξ y«¬ 9. 1, 2, · · · , 10 ÛsxÜ×°ØÚ{|Ý ßÞsßàßáâßÞsßãåäÚ½ßæÅßyßçèßé rßêß ξ < ξ < ξ < ξ < ξ . · ξ n ξ yßß߫߬ëßìßßßoßß×åØÎy (âßí ξ ≤ ξ ≤ ξ ≤ ξ ≤ ξ ), ξ , ξ n ξ y«îïðñ°¯ 4.
A
B
n
n
n≥1
n≥1
1
1
2
2
3
3
4
5
4
5
3
n
n→∞
1
n→∞
n
3
5
óõôõöõ÷õøõùõúõûõü ÿ**þ ¯*6*ÿ;dòÄ ® ò ¨ µ ¨ þ ;¹ Q¡;ÆÇ ; ; * £ * ý ÿ V ÿ ò ñ 8¡ ¹ Q % ò ¨ þH¹ p ÿ ä ¢£ ÿ*Bernoulli Q;¡; þ V ; ÿÒ ;ò B * V B ÿíRS;Çp ÿ*þ `;ao*V ÿ*ÿXg*Dß EW í ÿÆ p Bernoulli ÿ NOVí ECRWCSB ¡íCRCÇS p þHC ¡ Bernoulli ¥Cê B Bernoulli Bernoulli ò þ J ß þ N þ þ . ¨
# Q RSTU 6ÿX ò ß# 4 6ÿ à Bernoulli ÿ ò8 » ¡ Bernoulli §3.2
§3.2.1
ò
1
n
Bernoulli
Bernoulli
!y"#$}
é ®¹ Q EWB í£ O n V Bernoulli ÿþ `a Ê V ÿ Ò (« ¨ % ò ¨ ) òkª @ p, H0 <¹ p <¨ 1. ¹ Q ξ W ¼n ½V ¾ÿ òÒ V% þH ξ cç¡ Q ¡ÂTU ξ ò ¸d Ç&&'&(ì¡ N 3.1.5 îò&'&(ìò ì¤ìÝ ¹ Q + ° ìkìª ì {Ω, F, P }, ô*,; d Þ;N n X*D*E;_ W + ò ¬;1 A , · · · , A , P;Q;ò * k;ª) p (N þ ¥ 23 2.5.9 òh ° ). ç P ξ =I , ξ= ξ , 23 N 3.1.5 òh _ ¡* KL ξ ò ¼½¾f 1
n
n
k
Ak
k
k=1
+ Bernoulli ,-./0ÕÖ×Ø 89 1 Ç [ ®2 ò ξ ¡384 n V Bernoulli ÿ 65,Ò ò7V%8:9<;  þ Çûò= A >?@ iAB k V ÿ 5,Ò ò=C þD EF B k V ÿG þ ÿ F ω ∈ A , aH ξ = I = 1 ; EF B k V ÿIG þ ÿ F ω 6∈ A , aH ξ = I = 0 . JKL þM 4 §3.2
k
k
k
k
ξk (ω) = IAk (ω) =
(
ω∈A
1,
Ak
k
0, ω ∈ Ac
Ak
.
NO ξ P AQ n RSTU MVWX n YZ[6R7Y% \ U þ ξ R ]^_` A {0, 1, 2, · · · , n}. abcde k ∈ {0, 1, 2, · · · , n}, ) H H k d 1, ghd 0 ), (ξ = k) = ( f ξ , ξ , · · · , ξ i q = 1 − p, j6d A , · · · , A , 4 n klmnR=C þo ? cpq 1 ≤ j < H j < · · · < j ≤ n, ) 1
1
2
2
n
n
1
k
P
k \
\
(ξji = 1),
i=1
i∈{j / 1 ,j2 ,···,jk }
(ξi = 0) = P
H ≤ n R ]s
k \
A ji
i=1
t þo ?
\
i∈{j / 1 ,j2 ,···,jk }
Aci = pk q n−k .
6j d%r 1 ≤ j < j < · · ·
2
n
k
i
i=1
A { | i P b H
k k n−k n
b(n, p ; k) = Cnk pk q n−k , B(n, p).
k n
k = 1, 2, · · · , n ,
E F ξ R ] ^ _ ` A
P (ξ = k) = b(n, p ; k) = Cnk pk q n−k ,
(3.2.1) {0, 1, 2, · · · , n} ,
k = 1, 2, · · · , n ,
ξ {| ¡ ξ A {| i P ξ ∼ B(n, p) . ¦ {| M 4 n § Bernoulli Z[ G¨ Y©R{|~¦ª j ¢ £ ¤ > ¥ {|R«¬®~ ¯ 3.2.1 °±²6³´µ¶mn·¸ e±´ µ¶ ´³ § ¹º¼»6R ½¾ ¿ À ~eº»6feÁÂù§Ä´µRÅÆÇ4 p = 0.01. EFÈ (1) e´µ ÉÊ {ªË 20 ±´µ¶Ì (2) 3 ´µ ÉÊÍÎ ªË 80 ±´µ¶~ÏZ y H º» ÐÑÒ Á§ÄÓÔ´µRÅÆ~
ÕÖ6× 6Ø ÙÚ6Û Ü È cde±´µ¶ Ç >? ¬Ý© A p = 0.01 R Bernoulli Þ VWß 4àù§Ä´µ È T ß Ã¹§ÄÓÔ´µÁ âá Bernoulli R^ A 1, T Qß äРù§Ä´µÁ ãá Bernoulli R^ A 0. j6d°±´µ¶mn·¸ o Bernoulli klmn~ ? fæåæç (1) Î Áæo Ãæ¹æ§æÄæÓæÔæ´æ µèRæ´èµæ¶è±æ© ζ éÎ 20 i.i.d. R Bernoulli RS ?xζ ë H Ð{Ñ| Ò B(20, 0.01). T o Áù§ÄA ÓÔ ´µR´µ¶±©êdP 1 Á º» Áì§Ä´µ ? gÅÆ 90
1
1
20
P (ζ1 > 1) =
k=2
b(k; 20, 0.01) = 1 − b(0; 20, 0.01) − b(1; 20, 0.01)
æf åæç (2) Î Áæo Ãæ¹æ§æÄæÓæÔæ´æ µèRæ´èµæ¶è±æ© ζ éÎ 80 i.i.d. R Bernoulli RS ?xζ ë H Ð{Ñ| Ò B(80, 0.01). T o Áù§ÄA ÓÔ ´µR´µ¶±©êPd 3 Á º» P Áì§Ä´µ ? gÅÆ P (ζ > 3) = b(k; 80, 0.01) = 1 − b(k; 80, 0.01) ≈ 0.0087 . í çRîïð FVñ “3 ÉÍÎ ªË 80 ±´µ¶ ” ò6ó “e É ªË 20 ± ´ <µ ù¶ ú”ûÞ ü XÐ ý ô õ ö X ª Ë R A ± © a ý b ÷ ø X º¼» Ð Q Ñ Ò Á ì § Ä ´ µ R ÅÆ PþÆ véw ÿ ß `R P~ ùAéQ ÅÆîH ¤ ¬ dË Ro Rù®ú~ é R® é t îï §Ä ´ µ à R Á ¬d R~¹§Ä´µRÁ f à ¬ ÿ RÅÆ ! ·'¬ ÿ " RÅÆ î ¥ # ~ X$ % X& {| B(n, p), vw Þ vw gH 6RÅÆ b(k; n, p) q ( k R)a)R*}~,+ q = 1 − p, c k ≥ 1, = 1 − 0.9920 − 20 × 0.01 × 0.9919 ≈ 0.0169 .
2
2
80
1
k=4
o T
3 k=0
(n − k + 1)p (n + 1)p − k b(k; n, p) = =1+ , b(k − 1; n, p) kq kq
Á Q H M b(k; n, p) > b(k − 1; n, p); a T k > (n + 1)p Á H b(k; n, p) < b(k − 1; n, p). é f{ | } B(n, p) õ ÅÆ b(k; ùn, úp) R^- õ õ (0 k R êa ê aT k > (n + 1)p . ( k R êa/ ~ b(k; n, p) mÐ = (n + 1)p 6 © b(m; n, p) = b(m − 1; z n, p) Î 1g2gê2^êÌÏa^~43 5 (n +1)p b(k; n, p) f k = [(n + 1)p] 7] 2 é 6 © V W v w : z Ð 8 9 ê^~g [x] Ó© x R2ê 6 ©~ b(k; n, p) 1 2ê^ R; 6 © m {| B(n, p) R= R <>?@A (Ý BC 3.2). D v w z Ñ ¬ Ed 2ê ^R £¤ ð FG "H ¬Rð ¤ ~ ¯ 3.2.2 IJIKLMONQPRS6Æ p = 0.8, Í IK 10 Y~ y T R2ê Ñ RS6Y©~ Ü È e UY IUK Ç c « Ý © p = 0.8 R Bernoulli , VUW ° Y k < (n + 1)p
YZ[\]Ø6ÙÚ6Û 91 IKmn $ ¸ T S oNQP,R Y © ξ ^ é 10 klmnRÝ© Î p = 0.8 RÐ Bernoulli R S ξ Ñ {| B(10, 0.8). j6d (n + 1)p = 8.8 T S NQPR2 ê Y© m = [8.8] = 8 . é6 © ¯ ¥ 3.2.3 _`a b cdeRfg 2n Y y a F R;hR2ê Ñ Y©~ Ü È VUW ° YUaUb k l m n $ ¸ 3 ¥ o a F RU;Uh Y © ξ { | (2n + 1)p = Ð é6 © ¥ a F ;hR2ê Ñ Y© B(2n, 0.5). m = [ (2n + 1)p ] = =n. i ^ é f 2n Yab a F ;jhY©°kR Ñl 2ê~nm é i Ñlop H" êqOr vw Ðs D ¬ Stirling t n! ≈ √2πn n e Þu îv gwx ÅÆ ¥H §3.2
X
Bernoulli
2n+1 2
2n+1 2
n
b(n; 2n, 0.5) =
n C2n
−n
2n 1 (2n)! 1 = ≈√ . 2 2n 2 (n!) 2 πn
\ U i ÅÆ^( n Ryz õ êa{|6d 0, a ~vw “2ê Ñ Y© ” R F ÅÆ Ñ ë ~n^ Ñ Y© ” é Vñ¦ß R F ÅÆò6óg ß Y©R F ÅÆÇê Ð ß H êRwxÅÆ~
z p R ~ i ^} é o “2ê
é kcaR
vw j Bernoulli Z[ vw o ERwx ξ V Wo ÃRZ[Y© ξ ^ é Bernoulli Z[ ¨o ÃRZ[Y©~ \ U vw ¹Þ £¤ ξ R {|}~ ξ é -ª®~ ¯ 3.2.4 YY |6ON PIUK ° YIUK mn $ ¸ e YIUKUR VWo¤ RIK Y© Z ¡ Y S 6 Æ Ç p, 0 < p < 1 , S Q N P £ ~ ξ é ¢ y ξ R {|}~ \ U ξ R]^_` N = {1, 2, · · ·} . vw¥ ]ÅƦ {Ω, F, P }, : z gv¨w§ f© VkWlª mnURU {A , k ∈ N }, b H P (A ) = p, k = 1, 2, · · · . A k YIK S NQPR b« {ξ , k ∈ N } ^ é ©kξl=mInR , Î k = p1, 2,Ý· · ©· ,R Bernoulli ~ab Bernoulli
§3.2.2
k
k
k
k
Ak
k
i
(ξ = n) = (ξ1 = 0, · · · , ξn−1 = 0, ξn = 1) ,
j d (ξ = 1) = {ω|ξ (ω) = 1} = A , (ξl = 0)z = {ω|ξ (ω) = 0} = k ∈ N }, j¨¬©R {A , k ∈ N } Rklmn n
q = 1−p ,
Ack ,
n = 1, 2, · · · .
k
k
k
k
k
k
P (ξ = n) = P (ξ1 = 0, · · · , ξn−1 = 0, ξn = 1) = P (Ac1 · · · Acn−1 An ) = q n−1 p ,
n = 1, 2, · · · .
ÕÖ6× Ø6ÙÚ6Û v w w i { |¼nR P (ξ = n)
U® UU q = 1 − p , t¼nò RU¯ q © © ¯q{|~, H È 3.2.2 0 < p < 1 , n ∈ N , i q = 1 − p , vw 92
¯q{| i ¤
g(p ; n) = p q n−1 , G(p).
n = 1, 2, · · · , ξ
R]^_`
(3.2.2) N ,
b H
ξ P (ξ¯=qn){=| g(p¡; n) ξ= p ¯q q{, |n=1,2, · · · i, ¤ ξ ∼ G(p) . ¯q{|^ é ©§ Bernoulli Z[¨ ¡° ¨ F R j ¢ £ ¤ ¥ ± [ ° © R{|~ vw Þª ä² ¯q{| H ER®~ ¯ 3.2.5 e ³´µRO ê [ ¶s ¼6 U· U¸]U´µ ± I ~ © N V ± I W ° RO © N<Á ± ± IR´µÇ é ;¹ á º ú ³»¹ È à z ^¼± ¶y ~ á ³½´³µ´ì µ¼R ¶R¹ÅÆ Æ ~ p, IRw© n (n ò ³´µR¾©¿NÀ " ), Ü È j d ± IURU´Uµ é U ³ Á U F U © N ê U R U ´ ¼ µ  ¸ ] Þ R · Þ ÄÃÅ{ÇÈ Æ ß o ° ew ± á IR,´µÇ¬Ý© Æ ß p R Bernoulli ¹ß Á w « Bernoulli R^ 1, Ä;Å ¹¡Á° « g ° 0, b É Ê w á ¹ÁRI é n klmnRi ~, ζ °K È ¶ Æ© b ô Æ Èζ É ≤ n, Êo ìζ ¼ ¶¯RqÅ{Æ | G(p), q = 1 − p. d é ³´µì ¼ n−1
P (ζ ≤ n) =
n−1 P
g(p ; k) = p
n−1 P
qk = 1 − qn .
\Ë i åç¬ {|Þ &Ì ~ ú vw ¬ η ÄÅ n klmn j6d ß w RÝ©Ç é p, o η {| B(n, p). R Í R Bernoulli 3 ¥ á ³»¹ìº Æ b ô Æ η = 0, o 켶RÅÆ k=0
k=0
± ñ “f § mn ± [ ÅÆÎÏ ë wx ” RÐÑÒÓ~ Ü È á ÅÆ f ° ± [nRwUxÅÆ i ¤ p, ce ° ± [ðǬ ÄÅÈ á wx á Bernoulli R^ 1, á Bernoulli Þ W Ð wxÎ ^«g 0. j6d ± [ é mn§ $ ¸R o Ô ° ± [ðá ¡°Óf ÅƱ ¦° iR ¤ i.i.d. RÝ© p R Bernoulli oᬩë~ η, d é η ¯ i q{| G(p). \Ë wx wx ÁR [ © ^ éÕ η d½; 6 © n, ^ éH η < ∞. q = 1 − p.
¯
P (η 6= 0) = 1 − P (η = 0) = 1 − q n .
3.2.6
P (η < ∞) =
∞ P
n=1
P (η = n) =
∞ P
n=1
pq n−1 = 1 .
YZ[\]Ø6ÙÚ6Û i ^ ļñ Ð ¤ p U" URU U (η < ∞) wUxUR Å Æ ÇU d ; © ± [ ÅÆÎÏ ë wx ” RÐÑÒÓ~ “f§ mn vhÞÖ Å ¯q{|R H l× ~ Ø 3.2.1 o H ; 6 © ]^_`R ξ ¯q{| ô Æ cpq; 6 © m Í n, Ç H §3.2
X
93
Bernoulli
1.
i ^ é
G(p),
P (ξ > m + n | ξ > m) = P (ξ > n).
i l× ¯q{|Ry iÙl ~ ÚÛ È ξ ¯q{| Ç H P
o cpq; 6 ©
P (ξ > k) =
Í
m
∞
Ç H
+
G(p),
P (ξ = j) = p
j=k+1
n,
P (ξ>m+n) P (ξ>m)
=
∞ P
(3.2.3)
cpqÜÝ 6 ©
k,
q j−1 = q k .
j=k+1
P (ξ > m + n | ξ > m) = =
q = 1 − p,
Æ b
q m+n qn
P (ξ>m+n, ξ>m) P (ξ>m) n
= q = P (ξ > n).
j c p nqU~ ; 6 © m Í n, Ç H (3.2.3) U n ~cUÜUÝ 6 © k, v w i cpq; 6 © k, Ç H p > 0, bcpq; 6 p = P (ξ > k) . d é j (3.2.3) ¥ © m Í n, Ç H p = p 0· pß.à j ú n ¥ cpq; 6 © m,ú Ç H Ð p Ñ = po j6d p > 0, a Þ p = 1, cúÑÐ; á6 z© m, Ç H p = 1, c ½ d 1 R;© q, H p = q. j cpq; 6 © m, Ç H P (ξ = m) = P (ξ > m − 1) − P (ξ > m) = p −p =q −q =p q , o g p = 1 − q, ñ ξ ¯q{| G(p). v Uw â UUã ¯ q { | Ué ä U RUå H y iUÙUl R ] ^ _ ` ; 6 © _UR {v|w ~ vw . ë& ª ¯qu {|f«¬ÅÆæç H " ·¬~ Þ ª èé ç s " l RO ¯ 3.2.7 100 êë H 5 ê¨ ìç ~ N<3~ É Ý ö ¸ë e É ¸] ê~ ± { c ÜÈ È (1) Híî Ì (2)Æ y íî¨ï t îï H É ± ¨ìRÅÆ~ [~ Híî ĸŠ]k ª d mn§ FUR Bernoulli o ξ Æ ê H É ìë o à ¹ É RU¸] ° © È ξ ¯q{| G(0.05). 3 ¥ ξ≤3Á H ¨ì~ H ¨ìRÅÆ ¥
(3.2.3)
k
k
m+n
1
m
n
m
1
m 1 .
m
1
m−1
m
m−1
m
m−1
ÄðÅèo ] F R 3 êðë “H ð η è è {è| ì ë ” Rðêè© Æ η 6= 0 Á H É ¨ì ~ o H É ¨ ìRÅÆ È B(3, 0.05). 3 ¥ ðð
P (ξ ≤ 3) = 1 − P (ξ > 3) = 1 − 0.953 .
η
P (η 6= 0) = 1 − P (η = 0) = 1 − 0.953 .
94
ï t & sR vðw cy íî oÅ (3.1.2)È R {| ( RÅÆ
ÕÖ6× Ø6ÙÚ6Û
à ~ ÄÅo ] F R 3 êë “H ì ë ” Rê© ζ ζ 8 ¯q{| ). Æ ζ 6= 0 Á H É ¨ ì~ o H É ¨ ì
P (ζ 6= 0) = 1 − P (ζ = 0) = 1 −
3 C95 3 C100
=1−
95·94·93 100·99·98 .
ñò (óôõñò ) & ö mn§ R Bernoulli ± [ ¡° ¨ ÁRÁ ( f ¯ q { | o ÃR ± [ ° © ) R {|åç~ f vw Þ £¤ ª r ° ¨ ÁR ± [ ° ©R{|å ç±~,÷ Ë° V i ¤e ° ± v[w R ¨ ÅÆÇ é \p,Ë 0 < p < 1. Ñ ] z Ð ª r ° ¨o ÃR R [ © ξ, Þ £¤ ξ R{|~ ξ R^ F d r R; 6 ©Î ~ o Æ v w W ø f
R ÅƦ {Ω, F, P } Ó ©klmnR p Ý©R Bernoulli {ξ , k ∈ N }. i q = 1−p. \Ë ce; 6 © n ≥ r, Æ b ô Æ “f ξ , · · · , ξ H r−1 ù& d 1, gùú 0, &b ξ & d 1” Á H ξ = n. &aùù (ξ = n) ùû&d “fù A ,o · · · , A ¦
H r−1 wx b A wx ”, j¦d A , · · · , A kl m&n P (ξ = n) = P (f ξ , · · · , ξ H r − 1 d 1, gú 0, b = P (f A , · · · , A 6
H r − 1 wx b A wx ) = C p q . i §3.2.3
Pascal
k
1
n−1
n
1
n−1
n
1
1
o
∞ X
r−1 r n−r Cn−1 p q =p
r
n = r, r + 1, · · ·
∞ X
r−1 Cr+k−1 q
k
ξn = 1)
r−1 r n−r n−1
n
r−1 r n−r pn = Cn−1 p q ,
pn =
n
n−1
n−1
ü Ë H ∞ X
1
(3.2.4)
= p r (1 − q)−r = 1 ,
RÐ ùé Ä ñ ß UR{ |} ~ vw g ÄUÝÅ© o p Í r ¬Ý ¼¨R ° Uý R Pascal Ý {{||~,~ ý 3ª 5°þ Ýz © ¨ p Í ±1 ÿ R ° Pascal {| ^ é ¯q{9 |~ i Ðô é j6d¯q{|z ^ ÁR ©R {| abU¾ f (3.2.4) ¨« r = 1 é ¯q{| G(p) R{|}~ vw ζ ÄÅ F ª 1 ° ¨ ÁR ±ÿ ° © ζ ÄÅÀª 1 ° ¨ . ° F¨ ª 2 ° ± ÿ¨ ° ÇR ± ÿ ß ° w © , · · · , ÄζÅ Äþ Åz Àª ° r−1¨° o ¨ ±. ÿ ° F ªo r R © ^±Ç ÿ é $ o ÃR © ° Ç ¯q{| G(p). ýj¦d° é klmn ¸ R ζ , j +1, 2, · · · , r n=r
n=r
k=0
(3.2.4)
1
2
r
j
Y Z[\]Ø6ÙÚ6Û 95 á é W ùÓ úf Î Å ÄÆUÅ ¦Uþ z ª R ° k l ¨ m nUý ± ÿ k ° Î { |ÂR ( i i.i.d.)
~ cd r ÁR¾ ©R ξ Þ ^ « H o ce; 6 © n ≥ r, H ξ(ξ==ζ n)+ =ζ (ζ+ ·+· · ζ+ ζ+ ,· · · + ζ = n), ζ Ç é þ ; 6 ©R o §3.2
X
Bernoulli
1
2
r
1
[
(ξ = n) =
(n1 ,n2 ,···,nr )
2
r
j
(ζ1 = n1 , ζ2 = n2 , · · · , ζr = nr ),
(3.2.5)
y c E n +n +· · ·+n = n R o HH ¬; 6 ©r (n , n , · · · , n ) ~ ª U ¬ “ n k Î RU { r Ð Î R j
U R î © U ¥ # ¥ ® y¦ F ”i R u “{ ” î©!îï i t ©vrwR© ¥ Í H C r~ R H ¬; 6 ©r (n , n , · · · , n ), Ç H 1
2
r
1
2
r
r−1 n−1
1
P (ζ1 = n1 , ζ2 = n2 , · · · , ζr = nr ) =
r Y
2
r
P (ζj = nj ) = p r (1 − p)n−r = p r q n−r .
R ïï Ð ½ o j ¢£¤ ð vw ° z i ð ² (3.2.4) à P (ξ~ i =un) =vCwx p ï q Ð. Î Fö Pascal {|~ vw Þª ï ² Pascal {| H ER!"åç~ ¯ 3.2.8 ( Banach #%$%&%' ) ½ É »)(%* íÂHÂï %+%, %%- H +%, n . ~ T ° þ F æ ¼)/ F . +, : ¬ ~ ± yÂT þ F % w 10 ¦ ú Á 2 3¨ú r . +,RÅÆ~ Ü È A ÄÅ54 0 ¦ ú 5 . l ¥ Á 7 6 ¼ n 3 ú r +,R~987 : y RÅÆ 2P (A). vw þ F 4 ° ³ þ z ° ¨ ξ ÄÅ þ z ª n + 1 ° ¨ Á R þ ° © ξ Ý© 0.5 Í n + 1 R Pascal {| (ù :°yþ F 4 RÅÆ é 0.5). 3 ¥ A wx Æ ô Æ ξ 2n − r + 1. : RÅÆ 2P (A) = 2P (ξ = 2n − r + 1) = C 2 . ¯ 3.2.9 ± y ;<= § R Bernoulli ±ÿ ª n ° ¨ wx ; ª m °> ? øRÅÆ~ Ü È ξ ÄÅ þ z ª n ° ¨ Á R ±ÿ ° © ξ Ý© p Í n R Pascal {ª| ° > ? p é ° Bernoulli ±ÿ üþ Ëz ¨ RÅÆ;~ @ A ÄÅ “ª ° ±n °ÿ ¨þ ;z øwx ” R ~ m A û “ n+m
j=1
(3.4.3)
r−1 n−1
r n−r
n 2n−r
r−2n
ö
96 n
° ¨
”,
ÕÖ6× Ø6ÙÚ6Û
: : y R ÅÆ^ é
P (A) = P (ξ < n + m) =
n+m−1 X
P (ξ = k) =
n+m−1 X
n−1 n k−n Ck−1 p q .
(3.2.6)
vw Þª i ®R ï «¬~ ¯ 3.2.10 ABò7CyDE F Ó¸ 5 E 3 GH~ 4 6 É I 4 E þ GRÜÅÆÈ v w p, 04 < p þ< 1, ± y 4 þJ zz 6¨°RÅƨ ~ ÄUÅK4 þ z ° ¨ : G E ³ ξ 4 z 3 à Rª E© ° ¨ ξ ; ݪ © °3> Í ? p R Pascal {| ~ é “ J : 6D ” R^ é wx ø ” R ^ é ξ < 6, ¬ çð “ 3 3 4 z ¥ “ J 6 ” RÅÆ ^ é P P (ξ < 6) = C p q =p + 3p q+ 6p q . Æ F Ð á ¯ p = 4 0.5 Á É ï ¢ Æ ÅF ÆN^ W é 0.5. z ù 3.2.11 5E 3G G O ì P 800 Q~ 6 A B L M ; 4 G ö ª E.R ¢ 7ò C~ ± å « Æ S{ TìPOr Ü ÈVU R« Æ é WX “ÞY 4 6 É ° þ GRÅÆ ” Rò6 Þª ZT°ì> P? [ 8F 4 0 -° G¨ E : 4 þ GÄRÅ54 þ ^ é “° ; ¨ v: ÞRò7C R[, ξ 4 ] ï à RE© ξ3 Ý© ø\2 ]Í ï p = 0.5 R ”Pascal Z^[ é J]56¨RÅÆ^ é k=n
5
k=3
2 k−1
k=n
3 k−3
3
3
3
2
P (ξ < 5) = p + 2 p q + 3 p q . 4 p = :0.5 _ `a 4 ¥ 4 J]56¨RÅ: Æ Æ . 87 4 J]56¨R = ^ é 467J ] 6bJ] R Å Æ . « W 11 : 5 R¼ò ZTUìP ] 550 Q 67] 250 Q[ ` ¢ å ç ó c Å Æ ¤ wde`URfF g!"UR : 4 “Zhijk ”.1654 lNm 2
2
2
2
11 16
5 16
Wf|gGno3 EhOpJ|7]qrÃshtPu[ v VPascal W; w fE5}~v yjzk\x G67yMz{m v h{iEd JQMm <= [ 4 \GfE
63~\GhRm Æ SZThP Pascal
} Z T[ §3.2.4 [0, 1] ; 3.1.4 } : ¡¢ £ ¤¥ ξ :¦§ Z^ ¨© [0, 1] ` ª « Z^m 07¬® m¯°± 0 ≤ a < b ≤ 1, ²³ ´ µ m ξ ¶·P¸ (a[0,≤1]ξ < °b) ±= fP (ξg<¹ b)¨−© P[a,(ξ b)< }a)=ºb −»a, ¼½¾ ¹ ¨ ©¿ À mÁ ª «Âà ÄÅÆÇÈÉÊ m ³x 3.2.11
Ë Bernoulli ÌÍÎÏ5ÐÑ7Ò5Ó7Ô 97 ÕÖ 3.2.3 ×³Ø (3.1.4) Ù ÂÃÚ t F (x) ÂÃ
Û~Ü ¨© [0, 1] Ý ª «Âà m)Þß U [0, 1]. fg £ ¤¥ ξ à¶áâ ß ¨© [0, 1], ãä׳ ¾ Ø å ξ ¦§ ¨© [0, 1] Ý ª «Âà m Ç Þß ξ ∼ U [0, 1] , ã Ùæ Âå ÃÚ t F (x), £ Æ ξ ß U [0, 1] ¤¥ ³çÆ m èéêë ¢ i.i.d. Bernoulli £ ¤¥ìíîïð U [0, 1] £ ¤¥ñ ò g º»ó© (Ω, F, P ) } fíôõö ÷ ê p = ß {ξ , n ∈ N } ø t Bernoulli £ ¤¥mù §3.2
1 2
n
ζ=
∞ X ξn . n 2 n=1
(3.2.7)
î ú5û ζ fg U [0, 1] £ ¤¥ Æ ü | m ¯ýg ω ∈ Ω, þt P ²ßÿþtmãä³ ∞
ξn (ω) 2n
n=1
ê
∞ ∞ X ξn (ω) X 1 ≤ =1<∞, 2n 2n n=1 n=1
Å m È ä
¸ m
(3.2.8)
} þt ¸ Ω }m ´ ¯ýg ω ∈ Ω, ζ(ω) = P 0 ≤ Þζ(ω)ζ ≤=1.P , (3.2.8) Ù 5û ∞
(3.2.7)
¯m Þ ½ ¯°±t
n=1
m
m
n=1 m P
n=1
7º» é
ξn (ω) 2n
ζm =
↑ ζ(ω) ,
m P
n=1
ξn 2n
m→∞,
↑ζ ,
∀ ω ∈ Ω,
m→∞.
(ζm < x) ⊂ (ζm+1 < x), m = 1, 2, · · · .
(ζ < x) = lim (ζm < x) = m→∞
∞ [
§ È
(ζm < x),
n
o lim (ζm < x) = lim P (ζm < x) . m→∞ m→∞ 1 2 3 ζm 2m 0, 2m , 2m , 2m , · · · , 1 −m
m
[2m x] 2m
m
k<x
m
(3.2.9)
m=1
î ¾ Æ à ÷¶ !" # £ ¤¥ ãä$ à% }7ý ¶º» ² 2 , & ¯°± ²³ P P (ζ < x) = P (ζ = k) = , 7½ 2 x − 1 < [2 x] ≤ 2 x, ê lim = x , & È ³ P (ζ < x) = P
m
²³
ξn 2n
ζm (ω) =
x, ²³
ξn (ω) 2n
[2m x] m m→∞ 2
m
P (ζ < x) = lim P (ζm < x) = lim m→∞
m→∞
[2m x] 2m
= x.
0 ≤ x ≤ 1,
')(* 7Ñ Ò5Ó7Ô ê ζ = P U [0, 1] £ ¤¥ Æ ã ä (3.1.13) Ù +, (ζ < x) é í -. {(ζ < x), m ∈ N } ã á § È è £ -. Æ 98
∞
n=1
ξn 2n
m
/0 3.2 1. 132343536373839;:=<=>=?=738=@=A 6 B3C3D3E;F3G3H34 n I3J3K3L3E 2. F n I3M3N3O3P3J Bernoulli Q3R3S3T3U3V3W3I3J=K=L p . 3. X [0, 1] Y3J3Z3[3\3]3^3_=<=`3a=b=c [a, b] Y39;d3@3e3\3]3f3W=E 4. g=hji=k=l 20 I=J=M=N=m=n=9;oqpqrqI=mqnqJqsqSqL=ZqC 0.2, t ξ u=s=S=I=W=E;F=v (1)P (ξ ≥ 1); (2)P (ξ ≤ 2); (3)ξ J3w3x3y3z3E 5. 43{363|3}39j~33@3A=J3K=L=C p (0 < p < 1), p ξ C3:3343<3~33@3A3C=D3==34=J I3W39;F ξ J3\3]33E 6. p ξ
3 U [0, 5](b3c [0, 5] Y3J3Z3[3\3] ), F33 4x + 4ξx + ξ + 2 = 0 `333J3K3L3E 7. o33{3|3}33@3~33J=K=L3 p (0 < p < 1), 3P33363|3}3:33~=3==3=@=A3=C D39;F3v (1) 343I3W3G3C k J3K3L p ; (2) G3H333W3I3J3K3L=E 8. 3M3N3O3P3J Bernoulli Q3R3S39t ξ 33 i I3T3U3J33323c393=9 ξ − ξ ξ 13\3]3E 9. 9 3¡¢£3¤3¥3E¦o3=r={3§¨=¡=©3ª=J=K3L=\3«=C 0.6 0.4, ¬33§3ª3®3M3N3E ¯3°3± 3²3ª 4 §3³3C3´3µ39;Fj¡=¶ i § (i = 4, 5, 6, 7) ¢£3·3T3C3´3µ3J=K=L p . ¸ ¹ “º3§353ª ” »¢¼39;½3¾3¿3À3£=»¨j¡3w=Á=Â=Ã=´3µ=J=K=L=¼3ĨŠ¯q° ÍÊqS=JqKqLqC 0.4, jÊ=S=J=K=L=C 10. 5=Æ=¤q¥=¡=Ç=È=ÉqÊq¤q9Ë:=q>qÌqÊqSqCqDq9 0.6, A33β3Ê39;F35=¥=Ç=Ê=¤3I=W=J=\=]3=E 11. p=Ï=Ð A ={=I=Q=R=S=@=A=J=K=L= 0.3, Ñ A @=A=J=I=W=Ò=Ó=Ô 3 2=9;Õ =Ö=× @=Ø Ù E (1) 5 I=M=N=O=P=Q=R=S=9;Õ =Ö=× @=Ø Ù J=K=L==Ú=ӨŠ(2) 7 I=M=N=Q=R S3ÛÅ 12. p3>3Ü3Ý3Þ33{qß=J=>=à=2=c=S=` 1000 á3Ü3Ý3â339;r=á=Ü=Ýq=ã=à=2=c=@=Ï=ä=J=K=L 0.0001, F3ã3à323c3@3Ï3ä3J=Ü=Ý3W=Ò=Ä=Ô ± 2 ¯ J3K3L3E 13. >3å3æ3¶3ç3è3X3{3é=ê3ë=ì=Ï3í =î=ï3ð 9 é=ê=©3Ú=W=í 3ñ T=ò3â==EͶ=ç3ó=ô 3í 3õ3ö é3ê3Ê ñ T3÷3J3K3L3 0.6, ¬33í Ê3÷3ø3ù3M3N3EúC3t3¼=û3K3L=â3=é3ê39 Q ¹ ¶3ç3ü3º3Æ3ì=Ï3í ¯3H=° ý=3þ=Æ=H¨Å 14. `953À3ÿ3 4 39 8 3S 4 39¦y3XÀ3ÿ 3@ 39 3Q=R=T3U={=I3E (1) >= Ì
= ; 9 = F = Q = R = T ¹ v 3 õ J39;ý= =` =U=«={=y I=¨J=Å K=L (2) >=Ì=M=N=Q=R 10 I=9;T=U 3 I=9 ¹ S39;F3Ñ=3> =@=S3w ={==239 ={ r 3J3K3L3E 15. Banach 16. Bernoulli !" o3p3{3Q3R3` r ?3x3y # ° A , · · · , A , $3¬ P (A ) = p , p + · · · + p = 1. X ö Q3R3M3N 3O=P n I3E;F A G3@3A k I3J3K3L39;e3S k ≥ 0, P k = n. 17. 3M3N3O3P3J3 _ % Bernoulli Q3R3S39;F A A &' @3A3J3K3L39;e=S i 6= j. n
2
k
i
2
1
i
1
i
i
i
1
r
n
i
r
i
i
i=1
i
j
1
§3.3
Ñ7Ò5Ó7ÔË)()*,+.-
99
/1012131415161718
§3.3
9 :);)<)=)>)?)@ ) ë ¢ ÝBABC ¡ ED ¬ ¯ £BF ¤¥)C º)G ³)HEI.J
û.KBC)H)L Æ
éê)M)N £)F ¤¥)C)O)P Å H Æ ÕÖ 3.3.1 Q)R ξ S Ÿòº»ó© (Ω, F, P ) Ý)C ¶ Ú)T ´ £)F -. ´ ω ∈ Ω, ²³ ξ(ω) ∈ R, ã䯰± x ∈ R, (ξ < x) ²)S §3.3.1
(ξ < x) = {ω | ξ(ω) < x} ∈ F,
¸ ¯ý (3.3.1)
Uå ξ S £)F ¤¥ Æ Å ¯ ½ ! " #£VF ¤¥WIXJ ½VY L Æ- Ý Z ξ S ! " # C Á £BF ¤¥B[ $ B \B] éB^ àB_)` é í ¶Æ QBR$ )\)] ^ à ³ éB^ ¶ ¯ ½ %Wa Cý a , (ξ = a ) = {ω | ξ(ω) = a } ²VS {a , a , · · · , a }, .Æb)c ) [ (ξ = a ), (ξ = a ), · · · , (ξ = a ) ï)Sd)H ¯ Ω C Â)e ´ ³ (ξ = a ) ∩ (ξ = a ) = Φ, i 6= j ; (ξ = a ) = Ω. ãä ¯°± x ∈ R, ³ 1
2
n
j
1
2
i
j
n
n j=1
j
(ξ < x) =
[
j
(ξ = aj ).
(3.3.2)
é í ¶ {a , n ∈ N } [ ³ô)f)C)g)R ´ {(ξ = a ), n ∈ N } ï Â)e ãä³ (3.3.2) Ù)dö Æ ê ¯ ½!"#£)F ¤¥ ξ, (3.3.1) ΩC ¯ ξ C°± é)^ ¶ a, ²³ (ξ = a) = {ω | ξ(ω) = a} ∈ F. ! " #V £ F ¤¥ VÝ j VÅ k ÿ µ Xû HVl FVmVnVU S Ÿº»óVo ÝVC Borel Vé )¼ phVÚ )½ T i Æ - Ý qVr m sÚ T V t é%ê ú1û ¯ ½ °%±sl Fsmsn ξ, (3.2.1) Ù ¯°± B ∈ B , ²³ %,a B )u )v Borel w (ξÆ ∈ B) = {ω | ξ(ω) ∈ B} ∈ F, é)ê x )y)z){ Q g)| i } 0 3.3.1 QVR ξ S Ÿò º»V ó o VÝ CVl FVmVn È g : R → R ~ é)pÚ)T η = g(ξ) è S Ÿ÷º»ó)o )Ý C)l F)m)nÆ Borel ×m B)Ú T m BÚ T |B])t CBB )BqBÆ r )p À |BC )¸ ) t ú5`)û~)Á r) { g)|
Æ ³BÆ ) |)C)) Þ Á g)| )
) A Á g)| ê a ½ F B m n D ® ÝF-.| ½ ) éê ¯ F)m)°n± Å l ÂÃ)Ú ξ,T )° i± T x, (ξ < x) ²)S)l S ¯)l $)C Q Z
é ê à ¯ d)¼) H h Ù )½ i ¯ ½ ÿ
j
ξ
j: aj <x
n
n
1
1
100
')(* 7Ñ Ò5Ó7Ô Õ Ö 3.3.2 Q)R ξ S Ÿòº»ó)o (Ω, F, P ) Ý)C)l F)m)n )å Fξ (x) = P (ξ < x) = P {ω | ξ(ω) < x},
x∈R
(3.3.3)
C ÂÃÚ)T Ƹ)_½)))) [ éê æ F (x) ))~ F (x). ) î))| ÂÃÚ)T C )Æb)c °±)l F)m)n C ÂÃÚ)T F (x) S Ÿ T w R Ý)C Ú)T Æ ) ³ i Õ) 3.3.1 °±)l F)m)n C ÂÃÚ)T F (x) ²×³)Q 3 ))i i£)¤)¥)¦ x < x , §)¨ F (x ) ≤ F (x ) ; (1) )¡)¢ i£)¤)¥)¦ x ∈ R , §)¨ lim F (t) = F (x) ; (2)©)ª)«)¢ i£ §)¨ (3)¬))¢ ~
ξ
ξ
1
2
1
2
t↑x
F (−∞) = lim F (x) = 0,
F (∞) = lim F (x) = 1 .
F)m)n ξ C)±)²)³ T £ F (x) = P (ξ < x), x ∈ R. F (x) S)l Z x < x [ ¨ (ξ < x ) ⊂ (ξ < x ), ´.µ)¶)C)·)¸)¹)º z F (x) C)·)¸)¹)» ¤)¥)¦ x ∈ R , -.)¼ {ξ < x − , n ∈ N } ~)·)¸)C)½)¾ ¼)¿À)Á)Â ½)¾)~ £)z F (x) = lim F (x − ) , ¤ Ã)Ç)±)È)É)Ã x C (ξ < x), Ã)S,´.µ)¶)C)Ä)Å)Æ)¹ z x − ≤ t < x − , Í)Î t < x , Ê)Ë n ∈ N , Ì ®)¯ i° 1
x→−∞
2
1
x→∞
2
1 n
1 n
F (x) = lim F (x −
£ ¨
n→∞
n→∞ 1 n+1
1 n
1 1 ) ≤ lim inf F (t) ≤ lim sup F (t) ≤ lim F (x − ) = F (x), n→∞ t↑x n n + 1 t↑x
lim F (t) = F (x),
Ï)Å)Æ)¹ z)Ð »
Ñ )¿Ò)Ó){ lim (ξ < x) = Φ, lim (ξ < x) = Ω, Í,´.µ)¶)C)Ô)Ä)Å)Æ)¹ z Õ)Ö ¹)» mVn ±V²V³ T SV×VjVl FVmVn CV±V² ÕVØ CVÙVVm)ÚVn Û ¿Ü VÝVÞVßV¿.àV V á V l â )¤)¥)¦)ð ï é ã)ä)å)æ)ç)è)é µ)¶)».ê)ë)ì.ë)í F (x) î)l)â ξ ±)²)³)ï a < b, ¨ t↑x
x→−∞
ñ ë ¤)¥)¦)ð ï
x→∞
P (a ≤ ξ < b) = P (ξ < b) − P (ξ < a) = F (b) − F (a) ; a,
(3.3.4)
§)¨
1 1 P (ξ = a) = lim P (a ≤ ξ < x+ ) = lim F (x+ )−F (a) = F (a+0)−F (a). (3.3.5) n→∞ n→∞ n n
ò)ó)ô)ð)õ,ö.¿ø÷ x = a î)±)²)³)ï F (x) é o)ù)ú)û)¿øü â)ý)þ ξ ã a ÿ è)é µ ¶)î F (x) Ë ú é ÷ x = a î)±)²) ³)ï F¿ (x))ü é Å)Æ ú)û)¿ü¥ ã a ÿ è)é µ)¶)ÿ 0; ë)í)±)²)³)ï F (x) Å)Æ ã â) ) ý þ ξ ) â ) ý þ ξ ¦ )ú è)é µ)¶)§)ÿ 0. (3.3.4) (3.3.5) æ à)á ü â)ý)þ ξ é)è é  é.é µ)¶)» à Â
! "#$%& ' 101 (B÷*) á ¿ ±B²B³Bï*+Bî*, ü âBý)þB±)² Õ)Ø ó å ×-BÚ)Û ¿/.Bó0Bü âBý)þ 1 ó0 ±)²)³)ï ¿32 î æ)ç)é ü â)ý)þ)Þ4)Û5 ç)é ±)²)³)ï (6789 5 çBé ±B² ). :*B ; Ë*< 3.1.1 = ?>A@BË ç ó*0 µB¶B ? CD á óB¼E æ 5 ç)é ü ¿ Ý; 1 89)çF)é ±)²)» ñ ë)ì Bernoulli â)ý)þ G 3.3.1 ° {ξ , n ∈ N } î*H 0 µB¶*B (Ω, F, P ) øé óB¼ i.i.d. é ß p = ÿ) I ï é Bernoulli ü â)ý)þ ¿ J §3.3
1 2
n
ζ1 =
KL
∞ X ξ2n−1 , 2n n=1
ζ2 =
∞ X ξ2n 2n n=1
0 æVç)é ü â)ý)þ ¿ Ý; 1 89 U [0, 1] ±)² ¿ OP Ý;Q)î ζ )îN M é ü ) i.i.d. â ý)þ)» §3.3.2 RSTUVWXYZ :;[\] ó^_`a ±)²)³)ï M ü â)ý)þb )écd » :*;?eAÕBB@ ÖÎ*f é¿ * ü âBýBþ é ±B²B³Bï 1 î*g*hBË ð ï*i ð R Ô*j*kB·B¸B¹ ¿ ÏBÅBÆB¹* j*k*7q r*Bs ¿ ÏBÅBÆ s ¹ ÕBÖ ³Bs ï)é*»mt)l ïË*¿/nK*oL \*ÝB)p îì u ë)ó í g)Fî*(x)H î*0Bg*ü hBâBË ý)þ ï*éi v*Rwt Ô*ïy z) { ó)ú)¿ î)u Ê)Ë ó0)| ÷ é}~ B (Ω, F, P ), Þ)ß)Ë)Ý)Ôgh ó0)ü â)x ý ÿy évwt ïyx þ ξ, Ì ξ ß F (x) ) ÿ ¿ :;
\ ó0 } 3.3.3 F (x) îg)h Ë ð ïi R Ô é jkq r)s ¿ Ï)Å)Æ s Õ)Ö s ét ï ¿ :; ζ1
2
F −1 (u) = inf {x | F (x) > u},
u ∈ (0, 1)
(3.3.6)
é n t ï Î ¿ ëgh é n t ï)î Ü é n t ï })é Ü ghn t ï û [ à**\ é*t * ï * * Ð, *ö v¢w*¡ t ï* 1 î*BÔ é / ß+*4*)ý Ü é gh n t ï æ gh é F (u) îgh)Ë (0, 1) (3.3.6) é £ Å)Æ t ï ÷ F (x) î)Ô é Å)Æ t ï û F (u) )î F (x) é ÔÜé)qÓ r h¤ é n t ï Ë < 3.2.4 = :;e @¥¦ ,§¨)ë (3.1.4) ét ï F (x), ó® Þ)0) ßü © }~ B (Ω, F, P ) ª«)ÿ (0,é 1)vÔ wé t ¬ O}P ~ B ò ËVå ÝVvÔw ®gh âVý þ¯° ξ, Ì ξ± ß F (x) )ÿy vw U (0, 1); ²89 ò å vï w)é ü â):ý);þ© )ÿ U (0,)1)ÿ ü â)ý)(0,þ 1) Ô é } :;)Þ)ß Ð,ö
) Ô - ô)ð n t ï ë ¤³´µ)ì ÿ
F (x)
−1
−1
¶· ¸ ! " ¹ 3.3.2 ººgºhsË ð ïºi R Ôºjºkºq rºsº Ϻ»º¼ s ÕsÖ s º é t ï 1 0)ü â)ý)þ évwt ï F (x) îH ½®¾ ì¿© }®~ B (Ω, F, P ) ªVÿ ® (0, 1) Ô é®¬ ® }®~ B
VV Ë ÝVÔ ü ó 0 J , Ð ö gh évwUt (0, 1)é ü â)ý)þ η, À ξ = F (η). :;\ ξ )î)ß F (x) ÿy ï â)ý)þ Á
¢¡ (3.3.6) Î 102
−1
F (x) > u ⇐⇒ x > F (u) . 1 ¡ η ÿ ü â)ý)þ)Î x ∈ R, F (x) ∈ R, Í ß ξ = F (η) î ó(ξ0)<ü x)â)=ý)(Fþ À(η)Ò)<Ó x)¦ =η(ηÿ
,
−1
−1
−1
−1
−1
∞
−1
n
n
n
n=1
F (x) =
∞ X
an Fn (x)
(3.3.7)
)ÿ vwt ï éÕ Ö Ä ¹ 3.3.4 vwt ï éÕ Ö Ä Q)î vwt ï ½¾ ì ¡ .0 F (x) q r Ì ë (3.3.7) Ù é F (x) Ûq rs ÷ +ÚÛ û Ü Ý Ì F (x) ÛÞ»¼ s Õ)Ö s º ¤ º º ß à s Þ × éºá ¨ æ F (x) ë (3.3.7) ºÙ ºâ 0 < ε < 1. ¡ § P a = 1, s ã Þ ã m ä vºå P a > 1 − ε, ç P a < ε. ºâ ¡ 1 Þ»¼ è ß+[ x < x ä x ∈ R, § F (x), F (x), · · · , F (x) Ó x = x véê x ,  F (x ) ≥ F (x) > F (x ) − ε, n = 1, 2, · · · , m, 9 n=1
n
∞
m
n
1 2
n
n=1
n=1
0
1
0
2
n
m
0
F (x) ≥
n
m X
n=1
0
n
an Fn (x) >
0
1 2
1 an Fn (x0 ) − ε 2 n=1 m X
∞
n=m+1
n
1 2
0
§3.3
! "#$%& ' ≥
103
∞ X 1 1 an Fn (x0 ) − ε an Fn (x0 ) − ε = F (x0 ) − 2 2 n=m+1 n=1 m X
≥ F (x0 ) −
ß
F (x)
∞ X
1 an − ε > F (x0 ) − ε, 2 n=m+1
ÛÞ»¼ s ë )Þ Ì
é Õ)Ö s
F (x)
R STUìíî :;e @ïf ü â)ý)þðñqðñb v ,§ðñ ü â)ý)þ ξ,
§3.3.3
X
Fξ (x) = P (ξ < x) =
P (ξ = aj ),
(3.3.8)
j: aj <x
î ó0 q r éòót ï :; ² ò å évw ) ÿðñ v w ð
* Ü æ² * v*w v*w t ï é ¨ Bî ß v*w Ø é ¨ õ Ó ð * ñ Í Î Ù Ý ô ë:;Óõ ö é K F ±
ß
Fξ (x)
pj = F (aj + 0) − F (aj ),
÷
ξ
ÿðñ ü â)ý)þ û ß
pj ≥ 0,
X
j = 1, 2, · · · ,
pj = 1.
(3.3.10)
j = 1, 2, · · · ,
(3.3.11)
j
P (ξ = aj ) = pj ,
õÙ v w Ø {p , j = 1, 2, · · ·} jk (3.3.10) ã)è÷ Ä 6 © (3.3.11) ÍÎøù é ¨ j
a1 , a2 , · · · p1 ,
(3.3.9)
p2 ,
···
!
{aj , j = 1, 2, · · ·}
î
ξ
é
.
ó ^û ß v Á ,§qðñ vw ú []
:;â)á)ë¤gh)ì 3.3.5 F (x) ÿ vwt ï )ë íüÓH 0 ghÓ R Ô é qØ Lebesque Þý t ï p(x), æ Z x
F (x) =
p(u)du,
x ∈ R,
(3.3.12)
v®wVé ü âVýsþ ξ Vÿ®»®¼® ü V ÿ®»®¼® v®w® 8®ÿ 9 ® » ® ¼ â V ý þ éþt ï p(x) )ÿ F (x) )ÿ 89 vw)é ü â)ý)þ ξ éþt ï −∞
F (x)
104
¶· ¸ ! " ï ghÓ R Ô é Lebesque Þý t ï p(x) î þt ï ÷PÆ)÷ p(x) ≥ 0, ∀x ∈ R;
(3.3.12)
õ,ö , ¬ é
x ∈ R(
Z
∞
p(u)du = 1.
çµ ó0
p(x) =
−∞
Lebesque
d F (x). dx
(3.3.13)
÷ ), 1 (3.3.14)
ð ý t ï®´ Xé »®¼® v®w®t ï® ð Vî ®,®»®¼ é®v®w®t
v w §ðñ v ï Ó:;e @o évw N ú vw ¬ vw Û w U [0, 1] vw §»¼ vw Ý éþt ï)ÿ x≤0; 0, p(x) = 1, 0 < x ≤ 1 ; 0, x>1.
ÿ  ßÊ:; ó + Í)á p(x) é q 0 v ð ý t ï´ï å ï f ghÓ R Ô é q r t ïµ òót »¼ t ï :; \â)á ó0 ê! 7 ö ï ,»¼ t ï b Q ó z ð üÓ »¼ é vwt ï ) G 3.3.2 ("#$%RSTU& G ) t ï F (x) é gh ë¤)ì Á
J
À J Ê J é' À J
F (x) = 0 , x ≤ 0 ;
F (x) =
F (x) =
F (x) =
(
F (x) = 1 , x > 1.
1 1 2 , <x< . 2 3 3 1 4 3 4
1 8 3 8 5 8 7 8
, ,
, , , ,
1 9 7 9
<x<
1 27 7 27 19 27 25 27
<x<
<x<
<x< <x< <x<
2 9 8 9
2 27 8 27 20 27 26 27
; .
; ; ; .
O ë ó( ¤) .*1 ² (0, 1) > gh é .0+ 3 v Ó ó 0, - ./ © F (x) gh)ÿ ó0 ï (Ó< n * v Ê g h)ÿ v0 ÿ . óVú - v ! ÿ ï é®v ï ). §Vî Ó ® (0, 1) Xé Cantor é , ÷ Xé V 2 , V 1 21 Ê À Þ»¼ gh)á 3 ú -)é F (x) é)è F (x) µgh n
! "#$%& ' 105 é F (x) 4 Û® v®w®t ï é 3 Ç s®È® ßVî ó®0 v®w®t ï ® ë ® ® g h Þ)ß Ì,ö F (x) Q)î ó0 »¼ t ï ÷ x < 0, x > 1, ß5 ÷ x § (0, 1) .é Cantor é , ÷ û F (x) 1 Þ6 OP ) 6 ï 1 ÿ 0. ¡ § (0, 1) .é Cantor é , ÷)é Lebesque § 1, 6 ï ¬ ÿ 0, 9 F (x) î ó0 »¼ évwt ï ß F (x) é ) »¼ évwt ïÓ ð O æ Æ ÛÅ´ -)é7 h ð ý t ï´ . é Lebesque v8 Å´ ó0 (óÒ ) vwt ï F (x) 1 Û) 뤨 év8 ì §3.3
F (x) = a1 F1 (x) + a2 F2 (x) + a3 F3 (x),
x ∈ R,
(3.3.15)
v:9 ÿ*ð*ñ* *,*»*¼** : »*¼* v*w*t ï a ≥ 0, a + a + a = 1. ÷ {a , j = 1, 2, 3} ;N ) 6 æ ÿ 0 û F (x) )ÿ< Ä évwt ï ÷ é Æ ó 6)æ ÿ 0(9 é®ó v®)g w®ÿ t 1) û F (x) )ÿ= > éÄ vwé®t v®ï w® t é @ î®ð®ñ® M ®,®»®¼® ï ߮ʮ:®;®© ?®¥®¦ < ï A [ BC 3.3 1. D A E2FHG y = 2x − x I x JKLMNOPQSR A TUVWXQSYZX[ y JN\] ξ N^_`abcd`eaef 2. RghE R Ni2jHUVWXQkYeleXe[eimene\e] ξ N^_`abop P (ξ > n 2R/3). o , x> 3. ^rqrsrtrurdrNrvrwrx ξ yrzr{r|r}r~rr^r_rQrorprcrdr`a p(x) = ax exp − 0, T b > 0 2H
aQ a afkY a. 4. H
ξ Ncd`aE ( OP
F1 (x), F2 (x), F3 (x) 1
2
j
3
j
2
2
p(x) =
x,
2 − x,
0 < x ≤ 1,
1 < x ≤ 2,
x2 b
Y (1) ξ N^_`aQ (2) op P (0.2 < ξ < 1.2). 5. D ξ opcd`a p(x) = a cos x, − ≤ x ≤ , T a af (1) Y a b ξ N^_`a F (x); (2) p(x) b F (x) Nf 6. D p(x) = e , x > 0. (1) Y a p(x) Eecede`eae (2) eeee ξ el p(x) EcdQkY b P {ξ > b} = b. 7. Drrrrrr ξ Nr^r_r`rarRrO [0, 1] TrrrrrQ P (ξ ≤ 0.29) = 0.75, η = 1 − ξ, Ya x, P (η ≤ x)¡= 0,¢ 25. 8. D F (x) E^_`aQ Z Z π 2
π 2
−e(x−a)
+∞
(1) lim x x→+∞
(3) lim x x→0+
Z
x +∞
x
1 dF (y) = 0; y
1 dF (y) = 0; y
x
(2) lim x x→−∞
(4) lim x x→0+
Z
−∞ x
−∞
1 dF (y) = 0; y
1 dF (y) = 0. y
¶· ¸ ! "
106
D
9.
10.
F (x)
E^_`aQ
a > 0,
Z
D
£¤ +∞
[F (x + a) − F (x)]dx = a.
−∞
(
F (x) =
1 (1 3
+ 2x),
0 < x ≤ 1,
£ ¤ (1) F (x) W¥^_`a (2) F (x) ¦§]¨N©§eeeNeQ«ª¬e ®E¯°±²e^_e`eaeNeG³e´eµef 1,
x > 1.
¶¸·¸¹¸º¸»¸¼¸½¸¾¸¿¸À :;e @ éÁ µÂÃðñ vw lÓ[\Âû¼ vw : ;e @ïf »¼ vw F (x) 1Ä þtÅ p(x), jkÇÆÇ §3.4
p(x) ≥ 0,
F (x) =
Z
x
p(u)du, x ∈ R.
(3.4.1)
È Ó»¼ v w ûÊÉ @ §ËÌ þtÅ OP ÿ Â: + ú â Í þtÅ Ìq 0 v Ì Î −∞
Ï ÐÑÒÓìÔÕRS :;e @Ö×Ø [0, 1] - Ì ¯° vw U [0, 1].  : ; 3.4.1 a < b, ÙÚ vw F (x) Ä þ ÛtÅ §3.4.1
p(x) =
1 , b−a
a≤x≤b,
(3.4.2)
Ü Ý v wÞ [a, b] - Ì ¯ ° v w ± U [a, b]. Ù**g*h:Ì p(x) 4 :ß Â 0 }**~ þ:Û*t:Å Ü :à Í* *5 ( Ì vw*t:ÅÞ (á 3.3) F (x) =
0, x−a b−a ,
1,
x ≤ a,
a < x ≤ b, x > b.
4 È U [0, 1] ß ¯®° v®w U [a, b] Ì â ã á ä® ¡ § U [a, b] Ì v®w®t Å F (x) ´ß åæçèyóò Êè é x Óêë [a, b] Ììí ,ða î÷ø b ï- Ì ,»ð¼ áä Ó (3.6.2) ¦Ì F (x) ñ ÂæÌ ÉÊôõöÓêëÌ ö ßàù
úóûýüóþýÿ 107 à Ù Ù Ú à Ì Å !" Ó
# $ Å í % & 5 ' ( 6 ' <) * :+ :, :- = . / 0 >: ?à @Ì A é ξ 1 2 3 /:UD (−5 × 10 , 5 × 10 ). 46587:9:; Ù # :BAC Y S a EFGHI AJKL F A R S T ö MN COPQ 4UVOPW CX O:Z [COë ξ 23êë (0, a) \] U (0, a). ^_ êë (0, 1) \] U (0, 1) 4`ab ]cdef @ ' ô h õ gi j kl ù §3.4
−5
−5
m nop q:r ::s:t e:f:]:`:a ? H 4 `:ab u:v:w e:f] @ 'ùHô:õx Wybz]{|} ~ ù a UV~ J σ > 0, §3.4.2
p(x) = √
1 (x − a)2 exp − , 2σ 2 2πσ
s:H {|}:~ùA k : ô : õ : f : W
< z ò Y h R p(x)dx = 1. Y ôõ _
∞ −∞
p(x)
R∞
x ∈ R.
: 4
R
(3.4.3)
\
Riemann
S::
p(x)dx . s p(x) ]}~ö } ~ ôõ J I . I=
−∞
2
Z ∞ Z ∞ 1 (x − a)2 (y − a)2 I = exp − dx · exp − dy 2πσ 2 −∞ 2σ 2 2σ 2 −∞ 2 2 Z ∞Z ∞ Z 2π Z ∞ 1 u + v2 1 r = exp − dudv = dθ exp − rdr = 1, 2π −∞ −∞ 2 2π 0 2 0 2
4\ ôõ xM è u = ,svH= , v èù I > 0, Z I = 1. (3.4.3) ] p(x) {|}~ù ¡ 3.4.2 ¢:£:¤:¥:¦ : (3.4.3) ] p(x) ::{:|:}:~ ¨§:©:ª : a î σ «~] qr N (a, σ ). qr = © Gauss ù q:r : ]::¬ N (a, σ ) V: Normal Distribution. _ q:r : v :7 : c @® qr N (a, σ ) ] }~¯{|}~ Φ (x) ¯ φ (x). qr a = 0, σ = 1 ]°± u cef] V² ³ õ ® ? © 4 ´ qr µ Φ(x) ¯ φ(x) Q¶ ´ qr N (0, 1) ] }~¯{|}~ù ·¸¹º (3.4.3) ]{|}~ φ (x) ]»± (» 3.4), S¼½³ õ ¾ MN wh¿ «~ a ¯ σ ]V²À _ x = a  © Z 1 φ (x) Á y−a σ
x−a σ
2
2
2
2
a,σ
a,σ
2
◦
a,σ
φa,σ (a − x) = φa,σ (a + x),
x ∈ R.
a,σ
ÃhÄÅ
108
ÆÇhÈÉ
@ ´ q r N (0, 1) ]{|}~ c φ(x) = e , x∈R _ © ³ Ë ® © Á x=0 Z Ê}~ù a 'Ì«~ù t Ï Ð # µÑ σ ] ÐÒ $ φ (x) ]Ó Ò 2 φ (x) 4 x = a ÍÎ . ÔÕÖ× ? σ ] ÐÒÏ φ (x) ]Ó ÒØÙÚ ³:Ë :Û ¢:£ ξ s 2:3 q:r : N (a, σ ) ]:Ü:Ý:Þ:ß à-:. Â:U:á x < a < x ,1 R P (x < ξ < x ) = ÒÏ × ? σ ] ÐÒÏ â Y σ ] ÐÒ $ -. `a P (x < ξ < x ) φ] Ð (u)du, 1 -. `a P (x < ξ < x ) ] Ð 1 Ò $ Ú â Y σ ] Ð×ã M ξ 4 x = a äåæ Ð ] ç è | Ú · 7 ® σ © qr N (a, σ ) ]±é«~ Ú qr N (a, σ ) ] }~ √1 2π
◦
2
− x2
√1 2πσ
a,σ
a,σ
a,σ
2
1
2
1
x2 x1
2
1
1
a,σ
2
2
2
2
φa,σ (x) = √
1 2πσ
w Ðê GÚ Â _ ´ qr
Z
x −∞
(u − a)2 exp − du, 2σ 2
N (0, 1) Z x
1 Φ(x) = √ 2π
] }~
u2 exp − 2
ëhì ]Qí Sîïw Ð (kð %]äQ −∞
Φ(−x) = 1 − Φ(x),
).
Φa,σ (x) = Φ(
x−a ), σ
ñ
(3.4.4)
x ∈ R, φ(x)
]Ê}~òó S
x > 0,
Q ô Â x > 0 õ G M Φ(x) ] ÐÚ H ö ] qr N (a, σ ) ] }~ ·¸ 4 Â _ 2
du,
x ∈ R,
(3.4.5)
(3.4.4)
Þß÷ Sk
x ∈ R,
(3.4.6)
Ð Ú â Y ñ ´ q r N (0, 1) ] Ð ]Qí S ø G Φ (x) ] 4: ´ Úq:r N (0, 1) ] ::Ð ]:_ Q:í õ # Φ(6) :ûù úµ:Ñ Φ(4) :Úû õ
ü<ý: þ: ÿr : \ Φ(6) g
:
P (|η| < 3) = Φ(3) − Φ(−3) = 2Φ(3) − 1 = 0.9974 , Ð Ï M Ú µ:Ñ Uá q:r Þ:ß : ]:òó ³:Ë òó © : ` a g < i q r ] 3σ . ¡ 3.4.3 3σ À ¢£ÜÝÞß ξ 23 qr N (a, σ ), § 2
P (|ξ − a| < 3σ) = 0.9974.
(3.4.7)
§3.4
\ ñ Á
(3.4.6),
109
ê!
P (|ξ − a| < 3σ) = P (a − 3σ < ξ < a + 3σ)
= Φa,σ (a + 3σ) − Φa,σ (a − 3σ) = Φ(3) − Φ(−3) = 0.9974 .
H qr
Ú ³ Ë gi Û & £ × ã M q r Ü Ý Þ ß ] H #" #q $#A% ' ] ò ó qr ÜÝÞß ξ 4Uá() N (a, σ ) ]{|}~ φ (x) ÍÍ æ Ð ]`a q ~ +* s \,£-. ³Ë ξ Ï _ 0.9974 ]`aæ() Ð 3 J /ª ()W01 ξ ]æ Ð23 w45 $ _ 0.003, (a − 3σ, a + 3σ) ] ³Ë® 6 01 © “3σ § ”. åW 3σ §789@ #:; ]óß<= \ © 6σ <= § (4 a ]>?@A σ). Y B i ES À ¸ CD ] 1ø + r N (a, σ ), § ¢£ÜÝÞß ξ 23 q 2
a,σ
2
P (|ξ − a| < σ) = Φ(1) − Φ(−1) = 0.6827 ,
P (|ξ − a| < 2σ) = Φ(2) − Φ(−2) = 0.9545 . _ ³ Ë Á Í=GHI u ef« J ÐÚ ³Ë WK H qr ] I Ú MN L # O ÝP ¿QRS O) ÜT ·U#V é#W ÞX 3.4.1 / E ( H QRS r N (50, 100); (YQRS 1ø O ) ξ 23 q (2) 4 qr N (60, 16). ¢£ E[\ # O ) ξ 23 f ZÀ (1) 4 70 P Ý E [\ # ÝP + Ú ] HÀ+@ ^_`QRSba 65 c ³Ë À ñ (3.4.6) G 1ø¢ û `aÀ
F
1
2
P (ξ1 ≤ 70) = Φ( 70−50 10 ) = Φ(2) = 0.9772;
P (ξ2 ≤ 70) = Φ( 70−60 4 ) = Φ(2.5) = 0.9938;
P (ξ1 ≤ 65) = Φ( 65−50 10 ) = Φ(1.5) = 0.9332;
P (ξ2 ≤ 70) = Φ( 65−60 4 ) = Φ(1.25) = 0.8944.
E [\ # ÝP §d^_(YQRS Ö J ¢£fZ ·¸ ü ý E [À \ ¢# £fZ4 §70^ _( H QRS Ú ÝP 4 65 efop =sH6h
§3.4.3
g
~
f]¤¥¦
Ú ¢£
p(x) = λ e−λx ,
§ ê!i p(x) sH `a{|}~ Ú ¡ 3.4.4 (3.4.8) kj<] p(x) :{:|:] l+m exp{λ}.
λ > 0,
µ
x > 0.
(3.4.8)
F (x)
© :«:~:
λ
]
g
~
110
ÃhÄÅ
ê! ø G
exp{λ}
]
ÆÇhÈÉ
}~
F (x) =
(
0, 1−e
−λx
x ≤ 0,
, 0<x<∞.
T æ ~ Ð Ú Ð Ü Ý Þ ß 4#p ξ 2 3 g ~ # ] Ü Ý Þ ß G#w Ú+g ~ # Ü Ý Þ ß 1 s w j] H#6 i 7#x Á ] ` #H#Ivji 7 a Ú j|}[ l g ~ÜÝ:Þß~~ 7 y WQ:¶ y y C : ] : Ü : Ý : Þ ß ¦ 4 z ` : a { ]
¦j]2O) Ú 4 Ð HIO l g ~:ÜÝÞß l ] sH6ê S ] u Ú s H ]# # ] H 6 “ # µ Ñ # # # C#D l g # = s # p# á ~ ”, ¤¥¦ l  Y³Ë u 3.4.1 / ξ æ~ Ð ]ÜÝÞß l § ξ 23 g ~ l+ Ñô n o#l # q#r#s#t#u
P (ξ > s + t | ξ > s) = P (ξ > t),
(3.4.9)
³Ë " Ibh Ú Ú ξ N# v # ]## O l ª © g ~ # # (3.4.9) 1 ] # ò s l 4 Ï _ s ] Q û l y j _ y y:]²: 1 x O ) t ]:`:ap:3 x Ox Ï ê ¢ #£ g _ Ú â Y s#¡ # # 7 © £ #) O t ] ` a “ ”, ¤ ~ #¥ M Ú µÑ 3 H \ ¬ l ñ y g ~ P ¦ J ¬w £© l«ª “§¨ ”] ] ® ] uH ] ¯°ò Ú 4z y `aj l+% Ë ±² y ¬ µ® ~ _
© \1ø F (x)
”
=]h
ê!
∀ s > 0, t > 0.
l
F (x) = 1 − F (x) = P (ξ ≥ x),
}~ Â _ g ~
“³´
l
”,
V
x > 0.
4 ê $ _ x ? %µ¥9´]`a Ú
w exp{λ} 23 ª ]ÜÝÞß ξ, w
(3.4.10)
ξ
}
“³´
ê y ( F (x) ²j] ê ¬ (ξ ≥ x) s¶· í l ~ ¤ ¥ ¤ ¸¹ l Sº ¸ (ξ > x). L / '¾ L ]2O) ( E 1ø ) 23«~ λ = 1 3.4.2 ¼ » æ ½ Ý 3 ] lg * ~ s # Ú (1)H¾¢ Ú+£#] ¿#p#À H#^#Á ¾ #L Í # #  E O#à ΠH#l ÄÆÅ#Í Ç ] æ#½ Ý#È#É# Ê E 2 ËÌ 1 ø#¿ 3 ]`a l YB O)Î % 3 à 6 l Ö ? )]`¿ L l uHÁ a (2) ¢£Ú ¿ à ÎO g ¾ Îæ½ Î [ Y Z\, ]`a g
F (x) = P (ξ ≥ x) = e−λx ,
x > 0.
§3.4
c
À
λ=
1 3
]
g
η
~
Q ¶#¿#ÚÈ#Ï H#Á
Î HI (1) j O)Ò s È HÁ ¾
l
L
¿
¾
L
É#Ê#Ð##¤
L ÂOÃÎ ÅÇ ¾ Y l+ª ÉÊÐ]O) ¤Z Á
f ] O#)
I V
111
l
]æ ½Ý l ¤ Ì Hs Á ]`aÒ ¾
η
Ð#Ñ « ~
L ] Í
p1 = P (η > 3) = e−1 = 0.368; p2 = P (3 < η < 6) = F (3) − F (6) = e−1 − e−2 = 0.233.
L ] Í O) s È HÁ ¾ L µ¥ÉÊÐ]O) l l HÁ Î HI (2) j Ì ¾ g l R ~ ]#: :ò: l ê bÈ HÁ ¾ L gÓÉÊ #j Ô O ) ]Ð µ¥ÉÊÐ Y l ] # O ) ]
#p#Ñ# #Õ#Ö#É#Ê#Ð# ] O#) ] Â ¤ ¤#Z ] ` a × o _ Y ÐÚ \, ØÙ 1. 2. 3. 4. 5. 6.
Ú Ú
ξ ÛÝÜÝÞÝßÝàÝá
(x3 , x4 ), (x4 , ∞)
0
(1) 7.
ξ ãÝäÝåÝæÝçÝèÝÛÝéÝêÝë (1) (6, 9); (2) (7, 12); (3) (13, 15).
N (60, 9), âìÜìí x1 , x2 , x3 , x4 î ξ ãìä (−∞, x1 ), (x1 , x2 ), (x2 , x3 ), ï Ûìéìêìð+ñòá 7 : 24 : 38 : 24 : 7. ì óòôìõìöìí M , ÷ìø AM ùìúìûìüþýìÿ BC N , ìëþí N Ûìä ä 4ABC BC ì Û ìÜ Þ ξ õ (0, 1) ï Û ü ô 0 < x < y < 1, ξ, ã ä (x, y) óòÛìéì ê ìý y − x !"ìë ξ #$ U (0, 1) (% (0, 1) ì Û ìÜìÞ ). ô ä (0, a) õ & í (& í Û '()*+,#$ U (0, a)). - â & í Û ./ Û Ü Þìßì à ξ
ÛìÜìÞìßìàìá
N (10, 4), â
3.4
â
ξ ∼ N (3, 22 ).
P (2 < ξ ≤ 5), P (−4 < ξ ≤ 10), P (|ξ| > 2), P (ξ > 3);
(2) 1ì 2 à c, î P (ξ > c) = P (ξ ≤ c). 0 ξ # $34ìÜìÞ N (110, 12 ), 156ìÛ7ìà 2
P (ξ > x) ≤ 0.05.
x,
î
8:9:;:<:=ÝÛ?>@:AÝÛ:B:C ξ(D:6E:F ) #:$:3:4ÝÜÝÞ N (160, σ ), á:G:H:I:JÝâ P (120 < ξ ≤ 200) ≥ 0.80, -ì K ü σ Û5LMNOPQSR 9. 0 ξ #$ N (0, 1), η = ξ T −ξ, U |ξ| ≤ 1 T |ξ| > 1 V â η ÛìÜìÞ 10. ì öì W ÛXYE (Zì ' ë6E ) #$D λ = á[ìàìÛ\ìàìÜìÞ]- â ë (1) XY E ^_ 2 6ì E Ûìéìê` (2) ÚbadcYe 4 f6ìE ü âghJiQ 5 f6EjkYlìÛìé ê 11. 0 ξ #$ì [ àìá λ > 0 Ûì \ àìÜìÞìü â η = [ξ] ÛìÜìÞ (ìm ï [x] no x Ûìp àìq Ü ). 12. rs ξ #$ì \ àìÜìÞìÛt ÜuJvwOxOyz{ì| Û ü]% 8.
2
1 2
P {ξ > s + t|ξ > s} = P {ξ > t},
∀ s, t > 0.
}~
112
§3.5
Poisson
Poisson ¡¢£ ¤¦¥ ¦§¦¨¦©dª¦¦«¦¬¦¦®¦¦¯¦¦°±¦¦³²¦¦´¦µ¦¶¦·¶¦¸ ¦©¹¦º¦¦»¦¼¦½¦¾¦¿¦«¦®À¦Á¦ÂÃĦÅƦ²Ç¦È¦É§¨¦© ¼Ê«ËÌÍÎ B(n, p) ®b¹ºÏÐÑÒÓÔÕ b(k; n, p) = C p q , k = 0, 1, · · · , n . Ö Ì×ÒØÚÙ×£×Û×Ü×Ý×Þ×ß×b¬×à×á n ª k ¢×â×ã×ä×bå b(k; n, p) ×æ×ç×è××° é ©ê¦ë¦ Poisson 즦í¦î¦Ï¦¦¦¦¦ì¦ïðë¦ñòæ¦çÍΦ¦ó é ¿ôÕ 3.5.1 (Poisson × ) õ×£××ö×Í×Î×× B(n, p ), ÒØÚ×÷×Ý×ø×ù×ï ð Poisson
§3.5.1
k n
k n−k
n
lim npn = λ > 0 ,
ú åûüýþÿÝ
k
(3.5.1)
n→∞
¢£
lim b(k; n, pn ) = lim Cnk pn k (1 − pn )n−k = e−λ
Õbå¾ìýþÿÝ n→∞
ïð
n→∞
(3.5.1)
ëbåì ýþÿ Ý
lim (npn )k = λ .
n→∞
1 n
1−
2 n
k,
£
··· 1−
Ô
n→∞ k
k−1 n
(1 − pn )−k = 1
lim (1 − pn )n = e−λ .
¬b£
n→∞
lim (1 − nλ )n = e−λ .
n→∞
n
(3.5.3)
(3.5.3),
lim (1 − pn ) = lim (1 −
λ n n) .
¦£ |1−p | < 1, ¦á n ¦¦ã¦ä¦¦£ |1− | < 1. ¹¦ºé ¦ å £° |a − b | ≤ n|a − b| ! "Üïð (3.5.1), á n→∞
n→∞ λ n
n
n
ˆ
(3.5.2)
n! b(k; n, pn ) = pn k (1 − pn )n−k k! (n − k)! 1 2 k−1 1 = 1− 1− ··· 1− (1 − pn )−k (npn )k (1 − pn )n . k! n n n lim 1 −
£
k,
λk . k!
$ å÷Ý (3.5.3)
n
|a| ≤ 1, |b| ≤ 1,
n→∞
äb£
(1 − pn )n − (1 − λ )n ≤ n|pn − λ | = |npn − λ| → 0 . n n
!"bì#© λ > 0, ¹º%
p(k; λ) = e−λ
λk , k!
k = 0, 1, 2, · · · ,
(3.5.4)
§3.5 Poisson
ú (£
&'
113
p(k; λ) > 0 ,
∞ P
p(k; λ) = e−λ
∞ P
λk k!
= e−λ · eλ = 1 .
λ); k = 0, 1, 2, · · ·} *¦à+¦Ô¦¦¾¦¦¦¦¦¦Ó¹º ,¬¦à¦À¾)¦Ý¦Ý¦-ö Ô÷{p(k; ÝÔ λ Poisson © p(k; λ) .*࣠$ !/01© Ö Poisson ì*bá n 2ã p 23ä*àñò4!"Ë5 k=0
k=0
b(k; n, pn ) ≈
(np)k −np e . k!
(3.5.5)
n 6ã ú7Ö 8 63©ÔÏ9§ï×ð (3.5.1), ¹º: p 23bà; np ¦ã39<¦©=)¦ Ì (3.5.5) ¦=>?@¦º*¦àA¦¨ Poisson ¦¦»¦æ¦ç¦ª¦Í¦Î¦ £ËB C © ¤¥ §¨bê×Õ 110 FGH 24 3äIKJÑFGL Poisson £DEÔ Ý]ìäMIK N ÂOPQRL ÝSTUL Ý]V WXÝZY]\[]¦Ç^È ] ¸_` ÝZ]Y a ¢* ਠPoisson + ÔÒb © ¹ºc d « e[ K f ê “FGL Ý ”,“ OPQRL Ý ”,“ TUL Ý ” ¤¥9 ¨Ì Poisson g ©ahi j £ãk l æÝm n Poisson 9 ¨Çao êÕ å Ì “[]_ ` ÝZY ”, £pq Rutherford rs l æÝt Ô Õ k
νk
np (k, 3.87)
0
57
54.399
1
203
210.523
2
383
407.361
3
525
525.496
4
532
508.418
5
408
393.515
6
273
253.817
7
139
140.325
8
45
67.882
9
27
29.189
u æ
16
17.016
2608
2608.001
≥ 10
ñ vw^ wxwy Rutherford w@wA ¨wzw{ wrwsw|w}w~ ¬wNw] ¸ α _w` Ý w Y]©ºà 7.5 Ô¾äM|}Ï n = 2608 ¾äM%ëϾ äM ¬ |}Ñ α _`ÝZY]©bÀ 2608 ¾äMº|}Ñ 10097 ¾ α _`K ¾ α _`K © JDK º å læÑ Ý m+êë Õb¿ «
cä ¾Mä M¬ Ô |3.87 }Ñ× α _`Z Ý Y] c α _`Z Ý Y]Ô k ä M¾ Ý %+ ν . ¿« ºà 3.87 +Ô Poisson ÷Ý λ, O k
}~
114
ì ¾äM¬|}Ñ α _`ÝZY ξ ¼÷ÝÔ λ Poisson ¼ P (ξ = k) = p (k, 3.87), Åç¸ np (k, 3.87) .bö/åê©b/ ö-Ô.*าºª |}. ν Ü?á©ÚÀ/ + Ô[]_` ÝÜ9 © à Poisson ¹º» ¾ªo 3.2.1 £ËBC © 3.5.1 ¯H" H ×¾Ú × ¡ ´¢× £ ©× ¾ ä¤ X ¢ p = 0.01. ê¥ K¦ õ£ 200 H ?Ô> “£ °§¨ ä © X ” °ãÌ 0.02, ªB«¬ §á® ¯ ¬q@°±Z² ³ Õà η /n×±××ä¤××X×H×Ý×b¹×º η ×¼×Í×Î×× B(200, 0.01), §BC : ¸>? ë!" ´3) ÿÝ r: k
P (η > r) =
200 P
b(k; 200, 0.01) ≤ 0.02 .
×Ò.2µ:׸שb¹×º¶O×Ñ×Àw·×£ np = 200 × 0.01 = 2, ¸.×° × ã bÌ× (3.5.5) a * àñò¹ Ô η ¼÷ÝÔ 2 Poisson ©aº0/ á r = 5 ä »K º £ P k=r+1
P (η > 5) =
∞
p(k; 2) ≈ 0.0166 < 0.02.
¬ ম 5 q@°±¦¼¦ù¦à>? “£½ °§¨¦ä¦ ©¦X ¦ 3Ì 0.02. ꥾JÍÎ B(200, 0.01) æç ú £ k=6
§3.5.2
P (η > 5) = 1 −
5 P
¦¦
b(k; 200, 0.01) ≈ 0.0160 ,
q@°±© Poisson ¿ÀÁ à ÄÅÆ 5
k=0
”
¹ ºÇ»Æ Poisson Ó Ëôò|}ÌK.
p(k; λ)
êüÈ
p(k; λ) λk (k − 1)! e−λ λ = = , k−1 −λ p(k − 1; λ) λ k! e k
k
ÉÊÉÊ©ÚªÍÎ
k≥1.
(3.5.6)
Ö
" á k < λ ä p(k; λ) .È k ÍãÍãÎ Ð á k > λ ä p(k; λ) ú . È k ͦãÏ3¦©¼ Ð ¦ p(k; λ) .¦ k = [λ] Ñ´¦ã¦¼R¦á λ Ô¦ÿ Ýäb k = λ λ − 1 ÑÒ´ã.©b²º-Ô Poisson ´ã*§.© .?Ñ׸××× (3.5.6) × Poisson ×× Ò×£×Ç×ÈשbÀ× e bê¥ × ¾ Ó×£×÷×Ý λ > 0 *× à Ô׬ף×ý×þ×ÿ× Ý .××××××× ××Ò×ø×ù (3.5.6) $ÖÕ»×Ƹ ¾ B C© ì Poisson Ö© ¸ØÙ K+Ô ÚÛÜKÝÞß©
&' 115 3.5.2 õ%à[]Ç^ÈäMIÚ¬[]¸×_`ÝáY]©â» ²ãääMIK[ ] ¸_ ` ÝZY ν ¼÷ÝÔ λ > 0 Poisson ©æ å Ö Ì ç g ]Åý _[] ¸_` ¢*è% ë» $ \__`*è% ë é ¯_`§êè% ë»Q ðë× " ©ª:ã »¢ p, 0 < p < 1, Å ä äMIKè% ë»_` ÝZY ξ © ³ Õ\ bå_[]¸_`¢*ਾ÷ÝÔ p Bernoulli ÈìÉ k »/ n ²êè% ë»ÕêÖ ¥è% ë»Öí¸ Bernoulli Ék . Ô 1; îè% ë»í ÒÔ 0. ̯_`§êè% ë»Q ðë" b¬à ²¦º¦ i.i.d. Bernoulli Èìɦ k © ¼¦ áã¦ä äM½Ia[¦] ¸¦_¦` ÝïYK»a¦$ ä e obê Ô n äè%ë»_`ÝZYðñ×¼×ÍÎ× B(n, p). å ã¦ä äM½Ia[¦] ¸¦_` ÝïY\ ¦¾ÈìÉk ν. Õ¦× e ¹¦º¦§ ν .¦Ý ì ïðëòóè% ë»_` ÝZY ξ À á ν = n ä ξ ¼Í
¹ºô+ Î B(n, p). å §3.5 Poisson
P (ξ = k | ν = n) = b(k; n, p) = Cnk pk (1 − p)n−k ,
k = 0, 1, · · · , n.
(3.5.7)
À· (ν = n) ¾ÈìQð© Ö Ì ν ¼ Poisson ¬à ν *§Ôûü ýþÿÝ©bÀõ»bê¥% q = 1 − p, ¹º*àA¨ö÷?Ñ P (ξ = k) =
∞ X
n=0
P (ν = n)P (ξ = k | ν = n) =
∞ X nλ −λ e b(k; n, p) n! n=0
∞ X (λq)n−k 1 1 · · (λp)k = (λp)k e−λp , = e−λ (n − k)! k! k! n=0
k = 0, 1, 2, · · · .
À×××¾2×£ø× $ù b²/úÚ×å Poisson Ék ( ×¼ Poisson ××ÈìÉ k )ν +Ï Èìûü dý¼ Poisson © À¾ÇÈ-Ô Poisson Èì ûü ë° ÉÇ© ¼À ¾ o`¹ º þ* à ÿ¸¾ “Èì ù ” »©:Ê«»KºÑæ* àר×× ö "×±××××à p Ô×÷×Ý× Bernoulli ÈìÉk η , η , · · · /n×¯× ¾ _` êè%뻩 ¼ å Z ¾ ð\Ý n, S = η + η + · · · + η Ê n ¾ []¸ $ _`K è%ë» _`Z Ý Y]¹ º S ¼ÍÎ B(n, p). ¹º òó ãä ä MIKè%ë» _`Z Ý Y ξ. ãä ä MIK[]¸ _`Z Ý Y]Ô ν ¾b ¼ ÒK è%ë» _`Z Ý Y\§áÔ 1
n
1
2
2
n
n
£
Ì/ Ð
(3.5.8)
¾ÈìÉkÚ¬à S Èì¾ÈìÉk Ö (3.5.8) ν Ìùä ¬àc S - Ô ÄÅ Æ , ó-ÔÈ
ξ = Sν .
Ö Ì
Sν = η 1 + η 2 + · · · + η ν .
ν
ν
ν
}~
116
ì© Ö «ÆÚê¥ ä ν ¯ ¼÷ÝÔ λ Poisson ú S $¼ Poisson °µ÷ÝÉ Ô λp, Ͼ ” ` ”p. ` p ¸ 2Zð\ Ô ¾_`§ è%ë»Ô p. Èìù ¯ £ ¤¥ §¨©oêbê¥ η , η , · · · /n¯ ÝïY = ν ¦ ¦ J Ѧ ݦÕ× (3.5.8) S ¦¸¦ K J Ñ ÝZY\?Î ê¥ η ú, η , · · · /n÷ ¯ ÝZ]Y ν ¾Ø Ú¬× × Ý× (3.5.8) ØÚ S × ¸÷× ×¾Ø Ú¬ ÝZY\Î ©b°µ§á¶O ×bÀ× · ÈìÉk×ö η , η , · · · °ì Bernoulli Ékö ν î! Poisson Ék ¬à S "È # © o×ê×bú ×å× $ × % Á×××&' Ú ν ´(× ¼× ) ü×××× §×È× ì ù S è - Ô “) ü ”. “) ü ” ñ»§¨*&' ¾+XBC êü , æ S Ò¾-C © §3.5.3 Poisson ./01 3.5.1 2 b¹º¸ÌñòæçÍÎ××× e ÿ3 Ï Poisson © å Poisson Á £ÒZð4 ì5 ©bÔÏ Poisson Á ì 5 b¹º»6 ®ë Poisson µ7 © ¹º 8 110 H FG LL Ñ»Îð\TU LLN ÂÎñ[] ` ¾¾[] ¸Î 9 ©²º¢* àù ! e ÌÈì ä¤ Ñ» “ÈX 9Ç_”. À· “ÈX ” “ ” ¢: ôÅé “X ” Ñ»äMM; ¢ÈìÉ k ©bê¥ å t ≥ 0, ¹ºà ξ /n ä¤ t àÊÑ»ÈX ÝZ]Y =< / n äM>M [0, t) Ñ»ÈX ÝZ]Y b¹ºc" bìïðëbåû ü t ≥ 0, ÈìÉk ξ ¢ ¼ Poisson Åé Ò÷ݪ t £Ë©Ö å°± t, ξ °±ÈìÉ k b¼ {ξ , t ≥ 0} ? à t Ô÷ÝÈìÉk b¹ºÖ ÔÈ ì µù 7 © ÌÀ· t ¾äM ÷ݬà- {ξ , t ≥ 0} Ô “Èì µ7 ” ý(: ©K"@Ñ t °äM÷ÝAÜK 乺B ¨È ì µ7 q- © ¹º » Úìïðë “Èì ÈX 9 ” ÝZY4:! Poisson µ7 © n äM>M [0, t) Ñ»ÈX ÝZ]Y Ö êʬ e å t ≥ 0, ÈìÉk ξ /
å 0 ≤ t < t , £ ξ ≤ ξ , Åé ξ − ξ äM>M [t , t ) Ñ»È X ÝZ]Y © 3.5.2 õ “ÈìÈX 9 ” ÝZY]øùêë¾ïðÕ 1 CDEF × Â Õ×°× ¡ ×äM>Ø M ÚÑ×»××È× X ÝáYñë× " å×û×ü 0 ≤ t < t ≤ t < t , ¢£ÈìÉk ξ − ξ ª ξ − ξ ë " © ν
1
2
ν
1
2
ν
1
2
ν
ν
ν
t
t
t
t
t
t
1
2
t1
t2
t2
t1
1
◦
1
2
3
4
t2
t1
t4
t3
2
§3.5 Poisson
&'
117
GH Â×Õ È ìÉk ξ − ξ IJK Óת×äM>M ˪ÒMX a N Ëb¼*% 2◦
t+a
[a, a + t)
a
IL <
t
£
Pk (t) = P (ξt+a − ξa = k) .
OP ÂÕ£Q I äM>MSRK££Q¾ÈX»ÑT åûü t > 0, ¢£ P P P (t) = P (ξ = k) = P (ξ < ∞) = 1 ; ÅéT=U J 3 I äMM; t RK´ ¯ »ÑV¾ÈXT £ P P (t) = o(t) , t → 0 ; éTb¹º®WXYNZX[\ I NO] I^ :T _ P (t) `ab 1. úcde fg h øùiT=!U(j λ > 0 >?kVl t > 0 mn 3◦
∞
∞
k
k=0
t
k=0
∞
k
k=2
0
Pk (t) = e−λt
opq krO)j t s
∆t,
c
Pk (t + ∆t) = k=0
k X
(λt)k , k!
k = 0, 1, 2, · · · .
tKöuv÷wsxÍky Pk−j (t)Pj (∆t) ,
j=0
iT e wÊ{
(3.5.9) 1◦ ,
z
k = 0, 1, 2, · · · .
(3.5.10)
P0 (t + ∆t) = P0 (t)P0 (∆t) .
(3.5.11)
P (t) |nUiM>M [0, t) R*NZX[\ I uvT=}~b t ãÍ t*b
} {j7 (3.5.11) I nãT=!Ó:w (nÛ ): =b, t≥0, R 0 ≤ b ≤ 1. d b b 1 P (t) e _ 3 0, ! P (t) b 1 0, T= b {b 1 I jT=< U¡f(j λ > 0 ¢z b = e . b£ 0
0
t
0
◦
−λ
P0 (t) = e−λt ,
t≥0.
|S¤ (3.5.9) wk k = 0 ¥x ¦ (3.5.9) w¨§k k = m − 1 ¥xT=©ª}«k ¯ T=kr° k > 2, n 0≤
± St
k P
Pk−j (t)Pj (∆t) ≤
e w z (3.5.10) s j=2
∞ P
(3.5.12)
k=m
Pj (∆t) = o(∆t) ,
j=2
Pm (t + ∆t) = Pm (t)P0 (∆t) + Pm−1 (t)P1 (∆t) + o(∆t) ,
t§*ª I
(3.5.12)
w ¯
P0 (∆t) = e−λ∆t = 1 − λ∆t + o(∆t) ,
¥x¬t®y
3◦
∆t → 0 .
∆t → 0 .
∆t → 0 ,
(3.5.13)
²S³*´ µ*¶S·*¸
118
¹º» ®y 3 z P P (∆t) = 1 − P (∆t) − P (∆t) = λ∆t + o(∆t) , ¼ e½ w¾¿ (3.5.13), z ◦
1
∞
0
∆t → 0 .
j
j=2
¼
*R T=ÀÁ k = m − 1 i I (3.5.9) w¾¿ Pm (t+∆t)−Pm (t) ∆t
+ λPm (t) = λPm−1 (t) + o(1) ,
∆t → 0 .
z + λP (t) = , e ËÌ ÍΣ ¯ (0) = 0(ÆÇÈÉ k ≥ 1), Ê ∆t → 0,
ÂÃ *¤ ~ I ÄÅ gh P . P (t) = e ÏÐÑÒÓ
_Ô ghÎZÕÖÎ×jØÍ {ξ , t ≥ 0} Ù{ÚÛ{ λ Î Pois¯Þ kr° t > 0 ßàáâ ξ mã ±ä j{ λt Î son ØͬtÜÝys (3.5.9) Ìå Þ n Poisson , k = 0, 1, 2, · · · . P (ξ = k) = e Ì å Èæçèéêë Poisson Î¥ àìík Poisson ØÍÎîïðñòóbß àØÍôÎSõ*ö ÷ø 3.5 1. ù=úüûþýþ ÿ 4 Poisson (1) 8 (2) 10 2. ù t !""#%$&' Poisson (! "()!* ). (1) þ% ù +&,- 12 !./- 3 !0213' (2) ù +&,- 12 !./- 5 !021.4? 5' % 3. 6þ ù 7 89:;<=9> 512 × 10 0 @ 1, A&BC0D9>,EFGHI0DJK 0 H 1, @K 1 H 0, 6HI 10 , 10 =%$&FG5 ? HI 4. þù 63 L,0 ù MNO (5 ∼ 9 P ) Q 180 R/ST025 ? NO,/STUVW 4 R 5. ù X 730 YZ[0\ ? Z[[%+&5L 365 R,]5R^_`a0\.45R dPm (t) dt
m
λm tm−1 −λt (m−1)! e
m
m
−λt (λt) m!
m
t
t
−λt (λt) k!
t
k
t 2
3
−7
b 4 YZ[[%+& 6. cd5e 500 fghQ 500 ?i 80\ ?i 8_`aMFG5fj\kd5 fj.4 3 ?i 8 7. lmnopqrs02t ù7uvwlmwxwulwmyz$|{w}w 0.005. G~F 7lx 1200 02lmno. 10 8. 6 ξ ξ
02 ξ λ > 0 Poisson 0 i = 1, 2, η = max{ξ , ξ }, η = min{ξ , ξ } 9. 6þ ù!""#þ ù ξ λ > 0 Poisson 0 ? ^ p, ? U^
01w!w"$|w η % 10. 02 ¡¢£¤¥¦ {p , k = 0, 1, · · · , } §¨©ª , k ≥ 1. « ,¬ λ > 0, ®^( λ =Poisson 1
2
1
2
i
2
1
1
2
k
pk
pk−1
λ k
¯
§3.6
Poisson
°²±²³²´¶µ²·¹¸²º²»
119
6ÅuƼþÇ ý½)!=úüû ^¾ λ = 60 Poisson W¿ÀÁÂÃ¤Ä 30 = H¼È 12. ÉW5þýÊË%Ì&ÍÎÏ`(ÐÈ^5 ? Poisson W¿Ñ 1 %$&3ÍÎÉW ^ 0.02, 2 %$& 1 ÒÍÎÉW 11.
§3.6
Ó
Poisson
ÔÖÕÖ×ÖØÖÙÖÚÖÛÖÜÖÝ
Þ ß²à²á ² ÏÐ §ãâåäåæåçåèåéزê²ë Ì å Þ2ì ä ÏÐåí ê²îåê²ë Ìå
§3.6.1
ï²ð²ñ
Poisson
ØÍÎ
¦ ßà²òÕÖÎײëØÍ {ξ , t ≥ 0} £ÚÛ²ó λ Î Poisson ØÍ Þ ζ ö ï²÷²òÕ² Î ø í²ù²ú Þ Ïвí²û ô²üÎ Ìå²ñ Þ þ t > 0, ÿ (ζ > t) ô õ ö ï ÷ ò Õ ä ù ú t ø í Þ ý ¯ % ù²ú t ó Þ ø í ² (ξ = 0) ô²õ ø Î ò² Õ ë ó 0, ÷²ÿ Þ ± t
1
t
P (ζ1 > t) = P (ξt = 0) = e−λt ,
ä ²ë ó λ βê²ë Ì å Î “ ²ë ó λ² Î ê²ë Ì å²ñ §3.6.2
ÏÐ ØÍ Þ ÷²ò² ! Õ r ä÷
Γ
t > 0.
Þ ” ï
1
ô²õ ÿ
æ
(3.6.1)
ζ1
Î Ìå æ£ ä ë
à²á
Ø Í ï²ð Îï Ìå £ Γ Ìå²ñ § â ¯ö Þ%þ òÕÖÎí²× ù²ëú ØÞÍ {ξ Þ%, þt ≥ 0} æ£ÚÛ ó λ Î Poisson ö r ζ ô²õ r ÷²òÕβø £ t > 0, ÿ (ζ < t) ô²õ ù²ú t ² æ²ø í Þ ÿ (ξ ≥ r) ô²õ ø ù²ú t ó Þ ø í ² Î òÕ²ë Þ È ÷²ÿ Þ ± æ
Poisson
t
r
r
t
Fr (t) = P (ζr < t) = P (ξt ≥ r) = e−λt
∞ X (λt)k
k!
,
t > 0.
(3.6.2)
"# £ t Î $%²ë Þ À$&'(% ñ þ ( %) Þ* pr (t) =
+, ¯Þ
∞
∞
k=r
k=r
X λk tk−1 X λk+1 tk d Fr (t) = e−λt − e−λt dt (k − 1)! k!
λr = e−λt tr−1 , (r − 1)!
Gamma
k=r
²ëÎ-.£/
Γ(r) =
R∞ 0
t > 0.
xr−1 e−x dx,
(3.6.3)
²S³*´ µ*¶S·*¸
120
01 Ì þ ï r > 0 23 ñ45 é Þ%þ 6 ë n, + 1) = nΓ(n) = · · · = n! , 798: ¯Þ (3.6.2) <; Î Γ(n Û²ë ñ À?$ ¼ @ ó p (t) £ï²÷=> r
p(x) =
λr r−1 −λx x e , Γ(r)
x>0.
(3.6.4)
A B Ñ (3.6.4) <; Î ä ë r 7 6 ëCD²øE° ë Þ 0<; Î p(x) FG£ ï²÷=> Û²ë ñ þ 8 Þ ÏÐH î IJ 3.6.1 K (3.6.4) L; Î p(x) M ó Û ëÎNOP Ìå F (x) Ù óK ä ëÎ Γ Ìå ÞR M Γ(λ, r). λ>0Q r>0ó ST ÆÇ Þ U-. ; Î ä ë λ Q r $²óWVXY ß . Γ(1, r) Î Û
1 2
1 n 2 2
2
t
r
1
k
r
1
r
t
k
1
ÖÙ ÜÖÝ þ ßàáâxMxxáx Þ o ÏÐ ä Ô ô xQx ; âxåøÎx ñ¡ b¢ A £7\o® í Borel $¤¥¦ t§ £¥¨ B© FGo²ª ÷«¬£ ñ ì ä¥o¦ · í © ª¸ `¥¹ «¥¬££ ¥ ¯û°º ¢ ë÷±( îñ £¥«¬£¥¯° ë³²µ´ ç¶ §3.7
»9¼<½9¾¶µ9¿<À½9ÁÂòº²» 121 §3.7.1 ÄÅÆÇÈÉÊ ¶ ·Ë íÌ ²ª ÷ÍÎ ñ Ï 3.7.1 Ð RÑÒÓÑ ªÔLÕ øÖ¥ α ×Îس٠ξ, RÑÒ ¥Ú + vÛ Ø³Ù Ü 10 − 1, Ý 8 ¦ T ξ ≤ 10 − 1 Þ¦ RÑÒ $K vÛ ß ÓÑà ¥×ÎØÙ ξ; á T ξ > 10 − 1 Þ¦ RÑÒvÛ ¥ØÙ © o 10 − 1. ^K T RÑÒâ ¥ vÛ Ø Ù Ü 10 − 1 Þ¦¶ · ã iä¦ ¢ ªÔ<Õ à Ö¥ α ×ÎØÙ åæç 10 − 1, á åiäèéØÙ ê ëì Ð η í Û ¥ vÛ ØÙ ¦ t§î r ξ ï p ©ðë ´ñòó §3.7
10
10
10
10
10
10
η=
(
ξ ≤ 1010 − 1,
ξ,
1010 − 1, ξ > 1010 − 1 .
ô Þ¦õ¶ ·ö η ÷ Üø ξ ¥ùú¦õû<ü9ý ø ξ ¥ÿþ , è£ê 9ç ô Í 9¥«¬£ ¥¦¶ · Ðùúê¦ ø ¥ «¬£ê 3.7.1 ξ Ü «¬£¦ ëì ø!" M > 0, # ð P (ξ > M ) > 0, $÷ â% & ëì ø!" M > 0, # ð P (ξ < −M ) > 0, $÷ ξ ´ % ê ξ ª'(¦ ø ç â ´ %) ¥«¬£¦¶ ·ð 3.7.2 ξ Ü «¬£¦ a < b, ëì $÷
a, η= ξ, b,
ξ
Ü ξ ¥«¬£ê * Ð Û+, Ø- ξ ¥«¬£ η
ξ>b,
í Û Ü
η
η = aI(ξ < a) + ξI(a ≤ ξ ≤ b) + bI(ξ > b);
./ Ð ø ÷¥ %0 ¦ ø12
c > 0,
3
a = −c, b = c,
(3.7.1)
ô Þ ð
η = −cI(ξ < −c) + ξI(−c ≤ ξ ≤ c) + cI(ξ > c)
ëì , Ø
¥¯° , Ø Ü F (x). 67¦ ξ
= −cI(ξ < −c) + ξI(|ξ| ≤ c) + cI(ξ > c). Fξ (x),
¶ · Ö Ì45
η
Fη (x) =
0, Fξ (x), 1,
(3.7.1)
%0 ¥«¬£
x≤a,
a<x≤b, x>b.
(3.7.2) η
¥¯°
122
å< Ì = ¦ * Ð Û+, Ø-
Fη (x)
8 9;: »9¼<½9¾
í Û Ü
Fη (x) = Fξ (x)I(x > a) + (1 − Fξ (b))I(x > b),
x∈R.
0 6>¦ F (x) ? x = a @ x = b A¯B ðCDEF + 0) − F (a) = F (a + 0), F (b + 0) − F (b) = 1 − F (b) . ® Ö GHI¯°¦ J § F (x) KL ÜMN I¯°ê ôÝ ¦ ëì F F(a (x) Oø «¬£ ξ 4 (3.7.2) 0P ø ÷Þ¦ 67
(3.7.3)
(3.7.3)
η
η
η
ξ
η
ξ
η
ξ
η
Fη (x) = Fξ (x)I(x > −c) + (1 − Fξ (c))I(x > c),
x∈R.
(3.7.4)
ø « ¬£Q ðR ªSù %0 ¦ T Ì ´Íó Ï 3.7.2 UV 9¦ -WXYZ6¥Ú[ØZ\Z] Ü 10 ^_ ê ëì`a b;c ¥ Y6\ ξ ådefØ\¦ $ ë ØLY & ëì de¦ $ghfXY6ê ëì -WXY6¥Ø\i P η, J § ©ð 6
η=
jkl L
(
ξ,
|ξ| ≤ 106 ,
0, |ξ| > 106
≤ 10 ) . ô Þ¦ - η ÷ Ü ξ mnopqη r= s ξtI(|ξ| ξ munvê w'(s xy ð 3.7.3 ξ Ü opqrs a < b, ëì 6
η = ξ I(a ≤ ξ ≤ b) ,
m nopqrê ./ ø12 c > 0, 3 a = −c, b = c. ø c > 0, -opqr ξ ? ±c Anzs{|mopqr η m}~ , Ø ξ m}~ , Ø F (x) ï ðë ñòó $-
η
÷ Ü
(3.7.5)
ξ
Fη (x)
ξ
Fη (x) =
x ≤ −c ,
0,
Fξ (x) − Fξ (−c), −c < x ≤ 0 , Fξ (x) + 1 − Fξ (c + 0), 0 < x ≤ c , 1, x>c.
(3.7.6)
Ý ô s . / F (x) ? x = 0 A ð w 2 CD s CDEF Ü F (0 + 0) − F (0) = F (0 + 0) − F (0) + F (−c) + 1 − F (c + 0). ./ ö ø opqrm@n#÷ Ü “ù ”. ù?
º mZ@ Ð ; / Ðê η
η
η
ξ
ξ
ξ
ξ
; ; ;<À9ÁÂà 123 §3.7.2 ÄÅÆÇÈÆ ëì opqrm}~ , ØGHs-è÷ Ü GHmopqrê O tsGH m*}ã~ , ðØ¡å¢w] GHøI}~s Lebesque }mð F Ì s GHm}~ , Ø GHL}ê çGHmopqr ξ, xy
§3.7
?¬ ø GZHZoZî pZqZrZ mtê y# wS§ 0 ó Ï 3.7.3 ξ Ü
P mZqZ£¤¥s ðZ¦ S / ÐZmZ§ 0 x?Z∈¨ZR© .â @ Ф¥#Zª ðZ« opqrm}~ , Ø ð ñ ê opqrsè}~ , Ø Ü F (x), ® Fξ (x) = P (ξ < x) = P (ξ ≤ x) ,
ξ
η = Fξ (ξ) .
(3.7.7)
ø ô x y ð ¯ 3.7.1 ëì oZpZqZr ξ mZ}Z~ , Ø F (x) GZHZs $ZoZpZqZr η = F (ξ) ° }~ U (0, 1). xy ±;? (3.3.6) 0 ;² = e}~ , Ø F (x) m³ , Ø F (u) m]sµ´¶ ?Z]Z¨ 3.3.2 mZ·¤¸¥eZ¹¤¥·¤¸¥ó»ºZ¼Z½Z¾Z¿ZÀZÁZ U (0, 1) ÃZÄZÅZÆZÇ R θ, 2Ä Å%ÆÌÇÍ = ζ = F (θ) ¿ÀÁ F (x) (Èɫʬ © 3.3.1). Ë?m]¨ 3.7.1 $ w }~ U (0, 1) ?
© ;m (Îê ¯ 3.7.1 ÏÐÑóÒs xy ð 0 ≤ η = F (ξ) ≤ 1 . ð ç F (x) GHsÓ η = F (ξ) GHmopqrsÓ¶Ô (3.3.6) 0 >xó ø t ∈ (0, 1), ξ
ξ
−1
−1
ξ
ξ
ξ
Fξ−1 (t) = inf {x | Fξ (x) > t} > y ⇐⇒ Fξ (y) ≤ t ; Fξ Fξ−1 (t) = inf {Fξ (x) | Fξ (x) > t} = t.
(3.7.8)
ð P (η < t) = P (η ≤ t) = P (F (ξ) ≤ t) = P F (t) > ξ = P ξ < F (t) = F (F Ý ô R η = F (ξ) ° }~ U (0, 1). wSq£§ 0 $Õ Û Ö× Í Ø}~?
© ;m «¬ ( Îê Ø 3.7.4 ëì }~ , Ø F (x) ÙÚÛÜó ξ
−1 ξ
−1 ξ
ξ
(3.7.9)
−1 ξ (t))
ξ
JÝxy * ]
F (x) < 1 ,
∀x ∈ R,
R(x) = − ln (1 − F (x)) = ln
1 , 1 − F (x)
(3.7.10)
x ∈ R.
(3.7.11)
=t.
8 9;: ; ; *àZ+ ¨©@ >áâãR(x) 6 Þ
s
s ß G H s R(−∞) = 0, R(∞) = ∞. R(x) ? äåæ
çè# ðæ ê{Ë?s{xyÖ· ¸ R(x) ð ñmwSq£m ðé +ê ê ¯ 3.7.2 ëì opqr ξ m}~ , Ø F (x) GHs ÙÚÛÜ (3.7.10), á 124
ξ
ë
η = Rξ (ξ) ,
(3.7.12)
0 ]ê $opqr η ° Ö× Í Ø}~ exp{1}. ÐÑxóë øç !F" (x) GHð sì R (x) Ü ÞmGH , Øsì á η = R (ξ) ≥ 0 . í6>s x > 0, P (η < x) = P (R (ξ) < x) = P (− ln (1 − F (ξ)) < x) = P (F (ξ) < 1 − e ) . ;]¨ 3.7.1 >s opqr F (ξ) ° }~ U (0, 1), â0î |
è
Rξ (x)
(3.7.11) ξ
ξ
ξ
ξ
ξ
ξ
−x
ξ
(η < x) = P (F (ξ) < 1 − e ) = 1 − e , x > 0 , ô í ¸ η = RP(ξ) ° Ö× Í Ø}~ exp{1}. ï 9ç ëô s Ö× Í Ø}~ exp{1} ? áâãäåð ñ çè ðñòæ ê §3.7.3 óôõöÏ÷øùú åâ ,Zû à mZ#Z ZwZü / æ mZª ðZ«Z¬ § 0 mZqZ£ê ËZ?ZxZyÖZýZ©ZoZpZq rmþ Øê Üξ opqrs á g(x) ]?ÿmÿþ å , Øs i η = g(ξ), JÝ Ü ξ mþ å , Øê 9çþ å , Ø# GH , Øsµw] Ü Borel * ms η ÷ á η = g(ξ) Ü opqrê xy ò Öý© η m}~ê ëxì ξ ° I}~sÒJÝ η = g(ξ) m}~ 6xí = êÒ ξ m}~ Ü ó −x
ξ
−x
ξ
a1 , a2 , · · · p1 ,
JÝs O
g(x)
···
p2 ,
ÙÚÛÜ g(x1 ) 6= g(x2 ),
,
∀x1 6= x2
Þ s η = g(ξ) m}~ ð (
g(a1 ), g(a2 ), p1 ,
!
p2 ,
···
···
!
.
!
,
(3.7.13)
ò P w ü s xöð m
xê ë s å Ù x Ú Þ s $
á ξ m}~ Ü ó g(x) = x , O ÛÜ
(3.7.13) 2
−2, −1, p1 ,
p2 ,
1,
2
p3 , p4
; ; ; JÝs η = ξ m}~ Ü ó §3.7
125
2
1,
!
4
p2 + p 3 , p1 + p 4
.
ñ ý©GHI}~m§ê xywüªê Ø 3.7.5 opqr ξ ° }~ U (− , ), η = tan ξ, T η m}~ , Ø@ F , Øê óÒ6>s ø!" ÿØ x, ð π π 2 2
π π Fη (x) = P (η < x) = P (tan ξ < x) = P ξ < arctan x, ξ ∈ − , 2 2 Z arctan x 1 1 1 = dt = arctan x + , π π 2 −π 2
!
η
m}~ , Øê ô | pη (x) =
!
Cauchi
η
m F , Ø Ü
d 1 Fη (x) = , dx π · (1 + x2 )
x∈R.
}~m «¬ §ê w'(s xy- F , Ø Ü p(x) =
1 λ2 π λ2 + (x − µ)2
(3.7.14)
mGHI}~÷ Ü Cauchy }~ê 3.7.5 ;m ðη ° " m+ ÈØ λ = 1, µ = 0 m Cauchy }~ê Cauchy }~
© ;mwSª í m}~ê â$# Ê$% s Û Ü ξ ∈ (− , ) ñ ò P æ êÝ Ü O t ∈ (− , ) Þ s ? , Ø u = tan t &$' â$( s á î$) ?$* w m ³ ,,+ t = arctan u, ô Þ x y ð 0 L î ê.- ø ! S/ N s xy² = ë ]¨ó (tan ξ < x) = (ξ < arctan x) mñò ¯ 3.7.3 o p q r ξ ° G H I } ~ F (x), ð m F ,0+01 p (x), a < á ,+ u = g(t) 2 (a, b) â m&'mGH ,+ s î m³ ,+ h(u) = x < b. 12 2 (α, β) â m * % ,+ s ´¶è% ,3+ h (u) = g (u) ?2 g (u) F ,+1 ó â (α, β) GHs $ η = g(ξ) GHIopqrsè π π 2 2
π π 2 2
ξ
ξ
0
−1
0
pη (x) = p ξ (h(x))|h (x)|,
ÐÑó54ÿ â s O g &' â(6 s xy ð O Fg &(x)' = PÞ (η6 <s x)x=y Pð (g(ξ) < x) = P (ξ < g η
−1
d −1 du
x ∈ (α, β).
(x)) = P (ξ < h(x)) = F ξ (h(x)),
< x) = P (ξ > g (x)) = P (ξ > h(x)) = 1 − F 7 F8 (x)æ ñ= òP (η0
η
η
d dx
η
(3.7.15)
ξ (h(x)).
8 9;: ; ;
126 pη (x) =
@ Ø
d dx F ξ (h(x))
0
0
= p ξ (h(x))h (x) = p ξ (h(x))|h (x)|,
d dx {−F ξ (h(x))}
0
x ∈ (α, β),
0
1 o pqrs η = g(ξ). T}B 3.7.6 g(x) = a + bx, x ∈ R, b 6= 0. ξ ø ó (1) ξ ° U (0, 1), (2) ξ ° N (0, 1), = η m}~ ,+ @ F ,+ ê O ξ ° U (0, 1) 6 s η : 1 GZHZIZoZpZqZrZs ëì ó ¥F ]Z,¨ +3.7.3 Z 6 > ó 1 b > 0, $ p (x) = p = , x ∈ (a, a + b), ë ì ° ) ; η }~ U (a, a + b). b < 0, $ F ,+1 pη (x) =
= −p ξ (h(x))h (x) = p ξ (h(x))|h (x)|,
η
ξ
x−a b
1 b
1 |b|
x ∈ (α, β).
1 b
= , x ∈ (a + b, a), ° ) ; η } ~ U (a + b, a). O ξ ° N (0, 1) 6 s η : 1 GHIopqrs ëì b > 0, $ F ,+1 n o p (x) = p = exp − , x ∈ R, ëì b < 0, $ F ,+1 pη (x) = pξ
η
ξ
x−a b
x−a b
1 b
1 |b|
1 |b|
(x−a)2 2b2
√1 2πb
n o 2 exp − (x−a) , 2b2
x ∈ R, < ïs # ð η ° ï= }~ N (a, b ). Ë?s xy>ý©? 1 w'm§ê.:ê Ø 3.7.7 opqr ξ ° Ö× ï= }~ N (0, 1), η = ξ , T η m}~ê óÒ η 1 opqrs ð √F (x) = 0,√x ≤ 0. O √ x > 0 6 s √ xy ð F (x) = P (η < x) = P (ξ < x) = P (− x < ξ < x) = Φ( x) − Φ(− x) . η m F ,+1 pη (x) = pξ
x−a b
=
√ 1 2π|b|
2
2
η
2
η
√ d dx Φ( x)
√ d dx Φ(− x)
° ZGZHZIZ}Z~ F (x), ðZ m ZF ,3+31 p (x). á 3.7.8 ZoZpZqZr ξ ,+ @ F ,+ ê η = sin ξ, xy> η m}~ ó6>s −1ð ≤ η ≤ 1, @ ø x ∈ [−1, 1], AB F (x) @ p (x) mê
−1 < x < 1, xy Ø
pη (x) =
d dx Fη (x)
=
−
=
√1 2πx
exp{− x2 },
x>0.
ξ
ξ
η
η
Fη (x) = P (η < x) = P (−1 ≤ sin ξ < x) ∞ X = P ((2k − 1)π − arcsin x ≤ ξ < 2kπ + arcsin x) =
k=−∞ ∞ X
C ô s ð m F ,+1
k=−∞
{Fξ (2kπ + arcsin x) − Fξ ((2k − 1)π − arcsin x)} .
∞ X d d d pη (x) = Fη (x) = Fξ (2kπ + arcsin x) − Fξ ((2k − 1)π − arcsin x) dx dx dx k=−∞
; ; ;
§3.7
=
∞ X
k=−∞
√
127
1 {pξ (2kπ + arcsin x) + pξ ((2k − 1)π − arcsin x)} . 1 − x2
â#D Ee¹ ;s xy4ÿ â # 8 æ ,+ g(x) m³ ,+ mFG*w ? + @ *H+ s ø ô xyå· ¸;( <I ë ó ¯ 3.7.4 o p q r ξ ° G H I } ~ F (x), ð m F ,0+01 p (x), a < ëì * ö (a, b) }J 1 wü (ð 2 j *K 2 ) 2 (a, b) = S I , L| x < b. ,+ u = g(t), t ∈ (a, b) ?W 2 2 â ð *wm³ ,+ h (u), ´¶ h (u) ) ?G Hs $ η = g(ξ) GHIopqrsè F ,+1 ó ξ
ξ
j j
0
j
pη (x) =
X
j
0
p ξ (hj (x))|hj (x)| .
(3.7.16)
j
MN
3.7
OQPQRQSQTQUQVQW ξ XQYQZQ[Q\Q] ^ ξ + 2 _ cos ξ XQYQPZQ(ξ[Q=` 0) = , P ξ = ^ η = sin ξ XQYQZQaQbQ` 2. O ξ ∼ U (0, π), ^ η = cos ξ XQYQZQaQbQ` 3. O ξ ∼ U [− , ], ^ 4. O ξ ∼ U (−1, 1), η= XQYQZQaQbQ` 5. O ξ ∼ U (−2, 3), 1.
1 4
2 3
π 2
π 2
= 12 ,
P (ξ = π) = 14 .
π 2
1 ξ2
η=
QY c ^ η d
−1,
ξ ≤ −1
−1 < ξ < 1 .
ξ,
ξ≥1
1,
QX YQ^ ZQaQbQ` 6. O ξ ∼ U (0, 1), YQc ^ ee ,d 2ξ−2+ln1ξd XQ|ξ|eQfQXQgQeQhQfQaQgQbQhQ` aQbQ` 7. O ξ ∼ N (0, 1), YQc ^ η = ξ XQeQfQgQhQaQbQ` 8. O ξ iQjQkQbQ\ 1 XQlQbQYQZQm 9. OQnQoQSQTQUQVQW ξ XQgQhQaQbQ\ ( η
−2
ξ
ξ
2
2
YQc ^ η = , η = |ξ| d 10. OQTQUQVQW ξ sQtQgQhQaQb 1 ξ
1
(1) g1 (x) =
^
(
2
1,
x > 0,
−1,
x ≤ 0;
pξ (x) =
η3 = e−ξ pξ (x),
uQO
2x,
0 < x ≤ 1;
Qp qQr XQgQhQaQbQ` 0,
(2) g2 (x) =
(
x, 0,
.
|x| ≥ b,
|x| < b;
(3) g3 (x) =
b,
x,
−b,
x ≥ b,
|x| < b,
x ≤ −b.
QX YQZQm i = 1, 2, 3. 11. O.vxwQy I iQj 9 zQ{ 11 zQ|Q}QXQ~QQYQZQmQvwQ
2 Q X.vxQQmQQXQQf ^ \ W = 2I , W XQeQfQgQhQaQbQ` η = gi (ξ) 2
* Z?3¢Zw 2 Z
3£Z (Ω, F, P ) ¤Z]Z3¥ 2 (¦Z 2 j *3K Z x y ¥ Z 3 > Z ¡ s 2 ) opqr§©¨ª ! üopqrs xy« * F 2 ¬ym +ê @}~®s ¦ 6 Q ò¯ ¬y P1° r>¬ym± N +ê § © Ëÿ²³Ô{s Q
©´µs xy# * ² =¶ ¥ ò¯ ¬y P 1° r>± N +ê m§·s·¸ ξ ¹º w 2» mµ E së ξ ¹º¼  ñ s E ò ξ ξ F m 𽾿 ò & ·¸ ξ ξ }B 𹽺ÇÀÈÁ ¾ @ m mµ s JÝÃÄ3ÅZm " >ûZs.Æ3 Z 2 ξ° )3ξ ; m ¿ §.É·¸7?! 2 ¦ 2(0, 1) ¤,m+ Ê
£¤]w }Z~ U (0, 1) mo F (x) @ F (x), }BË F (x) @ F (x) ¹º ¬y pqr,+ η, 7 3 }~ ³Í » m s¾Ï ® ξ « = F (η), ξ = F (η),Í JÝ? ξ ξ ! ) ? ¦ " 2 S ¾¿ sÌÆ PÝ 1yάym ºm+§ ,B+ (m s.¦ ·2 ¸ opA q@ r Aξ = ¢I w
ξ £=I Ð;Îm §Lt m ¾¿4ÑÜs J| à ) §¾? ¿» áyâmãä Ò³ÓÔÕÖ³Ó×Ð;sxØ Í ÖÙÚ ¶ ¥ÛÜÝ¢Þ ! êß ª¦ ßðì ½ ä §å·æå·¸ðw½ çà ) Ò¾ÿ¿ 4ò3¥¯ èéêæåëÝ ° üä éê ξ , · · · , ξ íîïðª¦ñÜ æ.
¬3ò3óî3ç >3Ë3ô õ §,ö÷øù²ú áâ ° ä ßûü § §4.1.1 óôýöÏþÿ ò> áâ ° ä ßûü § ·3¸ ξ , · 1· · , ξ Í á â ¢3° î3ä ç û £3í (Ω, F, P ) ¤ ß Í n ç á3â3áã3âä æ ° ä ¯ (ξ , · · · , ξ æ ) ξ , · î· · ,ç ξ nÍ ¢î§ç û £æ í (ξ(Ω,, · F,· · ,Pξ ))¤ ß înç ç ná âãä § æ áâ ° ä æ ë¨Ý n ß Í (ξ , · · · , ξ ) îç n ö ÷ > æ · ¸ k Ô 1 ≤ j < · · · < j ≤ n , (ξ , · · · , ξ ) ð Í îç k áâ ° ä § !æ k = 1 "æ Í áâãä §.ÎËæ áâ ° ä ß Í îç#$ ûü § %'&'(') ô õ áâ ° ä ß Þ'*æ ò'+,'$'-.®îç/'01'23 áâ ° ä'4 Í'' ' ñç û' £í (Ω, F, P ) ¤ ß n áâ ° ä æ þ 5 4.1.1 (ξ , · · · , ξ ) 6 §4.1
1
1
2
2
1
1
1
−1 1
1
−1 2
2
1
1
2
A1
2
A2
n
1
1
−1 2
2
1
1
2
−1 1
2
2
n
n
1
1
n
n
1
1
n
k
1
j1
jk
n
{ω | ξ1 (ω) < x1 , · · · , ξn (ω) < xn } = (ξ1 < x1 , · · · , ξn < xn ) ∈ F,
128
∀ (x1 , · · · , xn ) ∈ Rn . (4.1.1)
7 89:;<= 129 >? 4A@B (ξ , · · · , ξ ) Í î3ç û C í (Ω, F, P ) D ß n á3âFE ä æ.ë Í G îç ûC íD ß n ç á âãä æ.ÎË ξ ,···,ξ T §4.1
1
1
n
n
n
(ξ1 < x1 , · · · , ξn < xn ) =
(ξj < xj ) ∈ F.
H I æ JKL n M Eä (x , · · · , x ), ðN (4.1.1) OóPQ.ëL ß M x, ËT M > 0, ðN k ÔRS T (ξ < M, · · · , ξ < M, ξ < x, ξ < M, · · · , ξ < M ) = (ξ < x) (ξ < M ) ∈ F. @BU M ↑ ∞, ë N 1
1
k−1
k
j=1 n
k+1
n
j
k
j6=k
T
(ξj < M ) ↑ Ω,
V D OWXYZ (ξ < x), [÷\Ú (ξ < x) ∈ F, ] ξ ^ áâãä Q _`a 0bcdefg 4 (4.1.1) OhiZL n Borel jk j6=k
k
k
k
B,
ðN
((ξ1 , · · · , ξn ) ∈ B) = {ω | (ξ1 (ω), · · · , ξn (ω)) ∈ B} ∈ F.
l mno páâãä îqæ ò,$ô õ áâEä ß rstu Q % ÷æ ò vSú n áâEä (ξ , · · · , ξ ) ßwxy ß 4 ñç û C í (Ω, F, P ) D ß n áâE þ ÿ 4.1.1 K (ξ , · · · , ξ ) ^ ä æ z{ §4.1.2
1
n
1
n
F (x1 , · · · , xn ) = P (ξ1 < x1 , · · · , ξn < xn ),
(x1 , · · · , xn ) ∈ Rn
(4.1.2)
% | áâEä ßwxy æ }{ F (x , · · · , x ) % (ξ , · · · , ξ ) ß~ k wx Q 4.1.1 æ n áâEä ßwxy ^ îç R ß n y Q HI æ òîç n y F (x , · · · , x ) % n wx æ @B ñç áâEä f % wxy Q p 1 wxy
æ n wxy NÞ* 4 þ5 4.1.2 n wx F (x , · · · , x ) NÞ* 4 ã 1 . F (x , · · · , x ) Lç ã W 2 . F (x , · · · , x ) Lç 1
n
1
n
n
1
n
1
◦
1
n
◦
1
n
3◦ .
lim F (x1 , · · · , xn ) = 0 ,
xj →−∞
lim
x1 →∞,··· ,xn →∞
ðN
n
4◦ . F (x1 , · · · , xn )
∀ 1 ≤ j ≤ n,
F (x1 , · · · , xn ) = 1 ;
NR D ß ä Þ 4 L'
(b ,···b )
∆(a11 ,···ann ) F =
X
±F (x1 , · · · , xn ) ≥ 0 ,
aj ≤ bj , j = 1, · · · , n
(4.1.3)
789: ð'N x = a b , jß = 1,ß · · · , n,%V ' x | = a + æ x =a j ç "æ è ß ¥¦ O 4 òSú n = 2 ¤ 3 " ∆ F
130
A N 2 ç'èæ îè æ ß j ß ç % "æ | è I % I % − Q % ¡¢&£ (4.1.3) Oæ n
j
j
j
j
j
j
j
(b1 ,···bn ) (a1 ,···an )
(b ,b )
∆(a11 ,a22 ) F = F (b1 , b2 ) − F (a1 , b2 ) − F (b1 , a2 ) + F (a1 , a2 ); (b ,b ,b )
∆(a11 ,a22 ,a33 ) F = F (b1 , b2 , b3 ) − F (a1 , b2 , b3 ) − F (b1 , a2 , b3 ) − F (b1 , b2 , a3 ) + F (a1 , a2 , b3 ) + F (a1 , b2 , a3 ) + F (b1 , a2 , a3 ) − F (a1 , a2 , a3 ).
>? 4 Þ* 1 ¤ j, 1 ≤ j ≤ n, x
§ gQ.Þ* 3 ߨ î穪hOóP«¬[ ^ 4 L → −∞ "æ.ðN T (ξ < x , · · · , ξ < x ) = (ξ < x ) (ξ < x ) → Φ. ¨ 穪hOóP«¬[z ^ 4 6 L®N« j, 1 ≤ j ≤ n, ðN x → ∞ "æ ¯N T ◦
1
2◦
◦
j
1
n
n
j
k
j
k
k6=j
j
n
(ξ1 < x1 , · · · , ξn < xn ) =
° *
4◦
óP«¬[ ^ 4
j=1
(ξj < xj ) → Ω.
(b ,···b )
∆(a11 ,···ann ) F = P (a1 ≤ ξ1 < b1 , · · · , an ≤ ξn < bn ) ≥ 0 .
G î±²îq³LZî´ ND 4 µ ° *« n y F (x , · · · , x ), ð|'e'f'¶'E·¼ î'´'w¸ x y « û'C í (Ω, F, P ), D'¹ ' î'´ n 'º'» EA¼ ³¾½'\ º» « ^ F (x , · · · , x ). p î±² ³ n wx }N¿ÀÁ wx ¤Á wx Q % øÃij f 6 f n = 2 %Å Q þÿ 4.1.2 @BÆÇ (Nª´ e Ç ´ ) M ÈÉ µÊ 4 1
1
n
n
∞ X ∞ X
pij ≥ 0,
pij = 1 ,
(4.1.4)
i=1 j=1
òwx {p@}B % Æ ´ 2 ¿rÀs Á wx% Q @ BÆ ´ 2 Ç º» E¼ (ξ , ξ V) Ë -¿À Á ³ ] (ξ , ξ ) « jk Nª jk e jk {(a , b )}, P (ξ = a , ξ = b ) = p , i, j = 1, 2, · · · , {p } %ÈÉ (4.1.4) O«M Ç ³ (ξ , ξ ) % (2 ) ¿ÀÁº» E¼ Q þy ÿ 4.1.3 @B F (x, y) ^ Æ ´ 2 wxy ³ V Æ ´ Lebesque eÌ « p(x, y), ½\ ij
1
1
2
i
1
i
2
ij
j
F (x, y) =
x −∞
Z
y
p(u, v)du dv , −∞
j
ij
1
Z
2
2
∀ (x, y) ∈ R2 ,
(4.1.5)
789:;<= 131 F (x,Ey)¼ ^ Æ ´ 2 Á wxwx³ p(x, y) % F (x, y) «Í0 % y Q @ BÆ ´ 2 º» (ξ , ξ ) Ë-Á F (x, y), Î (ξ , ξ ) (2 ) Á E ¼ V % y y º» ³ { F (x, y) «Í0 p(x, y) (ξ , ξ ) «Í0 Q
4 Æ 6 y y ö (4.1.5) Oec ´ 2 p(x, y) ^ Í0 ³ §4.1
1
2
1
1
Z
∀ (x, y) ∈ R2 ,
p(x, y) ≥ 0,
Z
∞
∞
2
2
p(u, v)du dv = 1 .
(4.1.6)
ò1 Æ Ï ¥ÅÐ Q Ñ 4.1.1 - w 'Ò'N 1, 2, · · · , 9 « 9 'Ó Ô'Õ AÖ'×ÙØ !
'Ú'Û 'r Ü 'Ó ³ w f ¨ Æ Ó¤ ¨ ÓÔÕD« ³ Î § c³ (ξ , ξ ) « rs jk % ξ ¤ ξ Ý {(i, j) | i 6= j, 1 ≤ i, j ≤ 9}, V ~ k wxu % 1
1
,
i 6= j,
1 ≤ i, j ≤ 9 .
2
1
2
1
2
2j
í
1 72
2
Ñ 4.1.2 { Ü ´Þ G «ßົ! ×á 3 ´âNã 1, 2, 3 «ä C ä'«'´ ³æf ξ 'Ý × N'ß'à'«'ä Ð «'ç'ß'ã'³éè (ξ , ξ ) « ~ ê 4 § c ξ « rs jk % {1, 2}, ξ « rs jk % {1, 2, 3}. ë § ú³ ξ = 2 "³ Ü ´ßà × G Æ ´ä ³ V | ä Ð × Nßà«ä Ð «çßã³ ì] ξ « s Q,öZ´ßàhe ( ! ³ ®f p = P (ξ = 2, ξ = j) = , j = 1, 2, 3 . ξ = 1 "³ Ü ´ßà × Ü ´Þ G ä ³.÷" × Nßà«ä Ð (% 1 2, ®f × Nßà«ä Ð «çßpã= %P (ξ1 "= ³ 1, N ξ Æ =´3)à =× 0 ; 1 ä ³ .
2 3 ä ³ Þïðú p = P (ξ = 1, ξ = 1) = ; × Nßà«ä Ð «çßã % 2 "³ Ü ´à w × 2 ¤ 3 ä 1
Ð^
−∞
2
pij = P (ξ1 = i, ξ2 = j) =
Ý
−∞
1
1 9
2
×
î
1
13
1
2
11
1
2
4 9
ñ ef Ç Æ ´ òóÝDô B4
p12 = P (ξ1 = 1, ξ2 = 2) =
2 9
.
(1, 1) (1, 2) (2, 1) (2, 2) (2, 3)
}ef ÇÆ Ó1Ý
4/9
2/9
(ξ1 , ξ2 )
1/9
« ~ k wxu 4
1/9
pij
1
2
3
1
4/9
2/9
0
2
1/9
1/9
1/9
1/9
!
.
2
Ð åQ f ξ k 'w x'u Q 1
«ã j ×á ´ä «çßã Æ ´àef ³ ®f
132
7 89: Ñ 4.1.3 õö³ @ « y ^÷ % ø ´ º» E ¼ « ~ kÍ0 y 4 ê 4 § Ä
p(x, y) = x + y , p(x, y) ≥ 0, R∞ R∞
0 < x, y < 1 ?
V
(4.1.7)
R1R1
(u + v)du dv = 1 , È É % Ü ®f p(x, y) (4.1.6) « ´ µÊ³ ù Í0 y Q Ñ 4.1.4 õö³ @ « y ^ ÷ %ø ´ º» E¼ « ~ k wxy 4 −∞ −∞
p(u, v)du dv =
0
0
(x, y) ∈ R2 ?
F (x, y) = I(x+y>0) ,
(4.1.8)
ê 4ú û 4.1.2 c³ º» E¼ « ~ k wxy üýÈÉþ µ ° *³ ÿR ·L | y N ∆ F = F (1, 1) − F (1, 0) − F (0, 1) + F (0, 0) = −1 , ¼ È É ° ]Þ ³ ®fÞ ^ wxy Q 4.1 1. (ξ, η) ( 1−e −e +e , x > 0, y > 0, F (x, y) = 0, F (x, y) 4.1.2 1 − 4 . % (ξ, η) &' 2. 1,2,3,4 !" ξ, # $ 1, · · · , ξ !" η. 3. # ()*+,-.0/12 34 0.4, # 34 0.6, 562,-789: D;,.<# $,.>=@?@A)@3@@@B % @# ,@-@2@ ξ C η &' .> 4. , x , x ) = x + 6x + , 0 < x < 1, 0 < x < 2, 0 < x < EF "p(x ELM N @O G@H@P@ @J@I GH@@@. @ 5. K f (x) p(x, y) = , x, y > 0 E (QGH 6. K (ξ, η) GH ( (1,1) (0,0)
−ax
−bx
◦
1
2
3
2 1
−(ax+bx)
◦
x1 x2 3
2 3
1
2
3
f (x+y) x+y
ce−(cx+4xy) ,
x > 0, y > 0
0, %R (1) S c; (2) &' F (x, y); (3)P {0 < ξ ≤ 1, 0 < η ≤ 2}. UTVR p(x, y) = Ke 7. GHWX@Y@Z √ a > 0, c > 0, b − ac < 0, K = ac − b . 8. K (ξ, η) &'GH y) = cxy , 0 < x < 2, 0 < y < 1. %R (1) S c; (2) ξ, p(x, η ?[A"\]^ _4 ϕ(x, y) =
−(ax2 +2bxy+cy 2 )
2
1 π
2
1 2
2
1 2
§4.2
`badcefghce
133
ikjklkmknkokpklkm q'ñsr
1
1
n
n
1
n
k n
k n
k n
1
n
1
k
1
n
F1,···,k (x1 , · · · , xk ) = P (ξ1 < x1 , · · · , ξk < xk ) = P
=P
k \
(ξj < xj )
j=1
n \
j=k+1
k \
j=1
(ξj < xj )
(ξj < ∞)
= F (x1 , · · · , xk , ∞, · · · , ∞) =
ƪ M«¬ qñ _` wx Å Q JK wº» w % @B @B
a < b,
lim
F (x1 , · · · , xk , xk+1 , · · · , xn ).
(4.2.1)
4 no®¯°±no²³´µQ ³Eë¼ §¶ P·~ no w«x |% ¸Q %§ Z¹º»³ 6 f w±w²x % (ξ , ξ ) « k F (x, y), Z ^ ξ ¤ ξ « x
xk+1 →∞,···, xn →∞
1
μxN
2
F1 (x) = F (x, ∞),
1
2
F2 (y) = F (∞, y).
P (a ≤ ξ1 < b) = F1 (b) − F1 (a) = F (b, ∞) − F (a, ∞),
qñ xefL ƽ
P (a ≤ ξ2 < b) = F2 (b) − F2 (a) = F (∞, b) − F (∞, a).
P (a ≤ ξ2 < b) > 0,
P (ξ1 < x|a ≤ ξ2 < b) =
x ∈ R,
¾ðµÊ|}
P (ξ1 < x, a ≤ ξ2 < b) , P (a ≤ ξ2 < b)
(4.2.2)
7 89: Þ°ïgb¿³ ú Æ¡\·Æ « wx x« yyÀ À P (ξI <% x|a ≤ ξ ¼ < b) N ° ³ tÁ °I ¤ W w³ x[y¡À ^ % ´ ³ º» Æ ξ { µªÊ a ≤ ξ < b «µ ÊÉ ³Â @ F (x|a ≤ ξ < b). ÃÄų { µÊ« Ê«|}ÇZ 0 ȳ ef yzÊ 134
1
2
1
1
2
2
< b), F (x|ξ ≥ a) ¦ O«µÊ wxyÀ Q LZ Fξ (x|ξ «µÊ wxyÀ ef ÅS© yz Q §4.2.2 ËÌÍα ú Z¿ÀÁº» E ¼ « wxÐÏÐÑ ^ f wx'u « ¦ O'SЩ'«³ ®f @ÐÒ û £ O®S©« ÂÓ ³ÔN ÆÏÕÖ ÿR I× Q v¹ ÆÏ ÅÐ Q Ñ 4.2.1 K w¿ÀÁº» E¼ (ξ , ξ ) « ~ k wxu @ ®ÝØ 1
2
1
2
2
1
(4.2.1)
2
pij
0
1
0
9/25
6/25
õ w Ä è ξ ¤ ξ « wxu Q ê Ø Db¿ (ξ , ξ ) « rs jk Æ {(i, j)|i, j = 0, 1}, Ù î ξ ¤ ξ « rs j k ^ ÜÚ jk {0, 1}. qñ «ÛÝÜ ^ w Ä è© ξ ¤ ξ r 0 ¤ r 1 «|}Q fè Pî (ξ = 0) ÆÅ Q { qñ «öÞ ³ N (ξ = 0) = (ξ = 0, ξ = 0) ∪ (ξ = (ξ = 0, ξ = 0) ∩ (ξ = 0, ξ = 1) = Φ, ®f 0, ξ = 1), Ƨ ÃPÄ(ξ³ß= 0)p ==PP(ξ(ξ==0,0).ξ = 0) +p P« (ξ¨ =Æ 0,´ξÜ = 1)“0”=Ý + ξ ==0, ¨. ´ Ü “ · ” Ý p Þ ^ ξ « rs |}Q LZ « p ¤ p efà¡è©Q á 4.2.2 @B (ξ , ξ ) « ~ k wxu ^ p = P (ξ = a , ξ = b ), i, j = 1, 2, · · · . p μ³ ξ ξ « wxu x w Ä ^ Ø 1
1
6/25
4/25
2
1
2
1
1
1
1
2
1
0·
2
1
9 25
2
0·
2
1
6 25
3 5
1
2
ij
1
2
1
i·
1
pi· =
1
1
0·
1
2
1
2
2
·j
2
1
i
2
j
2
∞ X
P (ξ1 = ai , ξ2 = bj ),
p·j =
j=1
∞ X
P (ξ1 = ai , ξ2 = bj ).
@B { (4.2.3) O p Å 4.2.1 « ~ k wxu ôkÃâ³Aef¹©Ø p x ^ _` ¨~ i ã w «x®u N|Â} § s «¤³ p x ^ ¨ j Ç «®N|} s «¤Q e f k ÅÝ© p ¤ p : ·j
·j
i·
(4.2.3)
i=1
pij
0
1
pi·
0
9/25
6/25
3/5
1
6/25
4/25
2/5
p·j
3/5
2/5
1
i·
M
Z ^
` adcefghce b Dº»Åb¿dØ |Å « §4.2
ξ1
¤
ξ2
« wx! u ^ 0
ì] ñ Gwx Q Ñ 4.2.2 K w'¿'À'Á'º'» EA¼ wxu Ø ξ ¤ ξ « 1
135
1
,
3/5 2/5
« ~ k w'x'u @ ''®'ݳ õ w Ä è
(ξ1 , ξ2 )
2
ê Ø _ `~ k wxu ³ P\
pij
0
1
0
3/10
3/10
1
3/10
1/10
pij
0
1
pi·
0
3/10
3/10
3/5
1
3/10
1/10
2/5
p 3/5 2/5 1 p Å w x u wxu
G Q eÄ ξ ¤ ξ « 4.2.1 « ξ ¤ ξ « Å « (ξ , ξ ) « ~ k wxu V Þ
G ³ ^ ξ ¤ ξ « wxuä D
G ³ ^ Æ ´ s \ÿR«åæ³ b¿dØ Þ G « ~ k wxu efN
G «v w xu Q ®f³çè wxu ef ú ~ k wxué Æê y ³J ^ °±noëìí ¯noëî´µQ å { â¹µÊ wx Q K (ξ , ξ ) Æ w'¿'À'Á'º'» EAI ¼ ³ @'B p w=xPu (ξ =
bï ) > 0, Îv¼'ô'k (4.2.3) O³xefèI © ξ { µÊ wxξ u = b «µÊ Q ų }efè© ξ { µÊ á ξ = a @«B µÊ Q 4.2.3 (ξ , ξ ) « ~ k wxu ^ ·j
1
2
1
1
1
2
1
·j
2
1
1
2
ξ2
j
j
2
{ µÊ
ξ1
2
I «µÊ wxu ^ Ø i, j = 1, 2, · · · .
pij = P (ξ1 = ai , ξ2 = bj ), ξ2 = b j
P (ξ1 = ai |ξ2 = bj ) =
î
2
2
i
1
μ³
2
{ µÊ
= P ∞
pij
P (ξ1 = ai , ξ2 = bj ) pij = P (ξ2 = bj ) p·j ,
P (ξ1 = ak , ξ2 = bj )
i = 1, 2, · · · .
(4.2.4)
I «µÊ wxu ^ Ø k=1
ξ1 = a i
P (ξ2 = bj |ξ1 = ai ) = = P ∞
k=1
P (ξ1 = ai , ξ2 = bj ) pij = P (ξ1 = ai ) pi·
pij P (ξ1 = ai , ξ2 = bk )
,
j = 1, 2, · · · .
(4.2.5)
ðdñbòdó Ævô âv'³ L'Z w'º'» AE ¼ (ξ , ξ ), @'B' { ø ´ Æ w Borel j'k B, ½'\ P (ξ ∈ wx Æ Ø I B) > 0 , μxef yz ξ { µÊ ξ ∈ B «µÊ 136
1
2
2
1
2
P (ξ1 < x |ξ2 ∈ B) =
P (ξ1 < x, ξ2 ∈ B) . P (ξ2 ∈ B)
(4.2.6)
±² qñ { {õ ¹«Áök ÷ Æø «ùbQ Ñ 4.2.3 õLúû Å «º»Uü ¼ (ξ , ξ ), w Äè© ξ { µÊ wxuþ ξ = 1 ý«µÊ ê Ø { Å 4.2.1 ³ ξ { µÊ ξ = 0 ý«µÊ wxu Æ Ø 1
2
1
ξ2 = 0
¤
2
1
2
P (ξ1 = 0|ξ2 = 0) = ξ1
{ µÊ { Å
wxu Æ Ø = 1 ý«µÊ
P (ξ1 = 1|ξ2 = 0) =
ξ2
6/25 2/5
P (ξ1 = 0|ξ2 = 1) = 4.2.2
³
ξ1
{ µÊ
P (ξ1 =0,ξ2 =0) P (ξ2 =0) P (ξ1 =1,ξ2 =0) P (ξ2 =0)
= 35 ,
ξ2 = 0
9/25 3/5 6/25 3/5
= =
= 35 , = 25 .
ý«µÊ wxu Æ Ø
P (ξ1 = 0|ξ2 = 0) =
P (ξ1 = 1|ξ2 = 1) =
P (ξ1 =0,ξ2 =0) P (ξ2 =0) P (ξ1 =1,ξ2 =0) P (ξ2 =0)
3/10 3/5 3/10 3/5
=
4/25 2/5
= 25 .
= 12 ,
µ Ê ξ = 1 ý«µÊ wxu Æ Ø { = , P (ξ = 1|ξ = 1) = = . P (ξ = 0|ξ = 1) = v¤vÿ Æ ´ ÿ «våvævØ çè { û' Å ³ ξ «vv w'x'u
³ ^ ñ {y ξ «µÊý«µÊ wxuä Þ
þ [¡ef³µÊ wx ¼ «
tuvþ Þïv¹©'³ Å 4.2.1 « ξ { µ'Ê ξ = 0 ¤ ξ = 1 Å 'Ýv©'º'»s ü ý«µÊ wxu p d« wxu
³ î Å 4.2.2 « ξ zÞ þ í ^ wº»Uü ¼ ³ Ò n wº»Uü ¼ þ qñ f û ® « â¹ Æ ´ n w¿ÀÁº»bü ¼ « ÅÐ þ Ñ 4.2.4 ÿ n ´ã ÿ 1, 2, · · · , n «ä Ð (n ≥ 4) m ´ «ßà³ ´ßà á k ä Ð «|} Æ p , k = 1, 2, · · · , n , ´ßà á ´ä Ð « ª Ê ¦ þ"! Ä# ξ , ξ , · · · , ξ $ Ý á ´ä Ð% à Àþ õèØ %*+ !,-. (1) &'bü)( (ξ , ξ , · · · , ξ ) % / !,-0"132 k = 1, 2, · · · , n ; (2) ξ % !,-. (3) (ξ , ξ ) / % !,-0"132 3 ≤ k < n ; (4) (ξ , ξ , · · · , ξ ) / % !,-þ (5) {45 ξ = m ý6&'bü)( (ξ , · · · , ξ ) 45 7 Ø98 0 (ξ , ξ , · · · , ξ ) %:;<+Æ P (ξ1 = 1|ξ2 = 0) =
ξ1
=
= 12 .
2
1
3/10 2/5
2
3 4
1
1/10 2/5
2
1 4
1
2
1
2
2
1
k
1
1
2
2
n
n
k
1
2
1
2
k
1
1
1
2
2
n
n
{(m1 , m2 , · · · , mn ) | m1 + m2 + · · · + mn = m, mk ∈ N , k = 1, 2, · · · , n}, (4.2.7)
`badcefghce 137 132 N $=>?@ À < þ BCC +DE 0GF + Þ 2 %HI 0GJKLM ØGN ÒO < (1) A + (4.2.7) %ÿP >?@ À C (m , m , · · · , m ), ÿ §4.2
1
2
n
P (ξ1 = m1 , ξ2 = m2 , · · · , ξn = mn ) =
m! n p m1 p m2 · · · p m . n m1 !m2 ! · · · mn ! 1 2
(4.2.8)
QSRSTSUSV (4.2.8) WSXSY n Z\[^]S_S`SaSbSc\d^eS`Sa 0gfSh M (m; p , p , · · · , p ). 0 N Ò m ∈ {0, 1, · · · , n}, P (ξ = m ) m k ÿno 45 m + (2) i)jkl %pq; P (ξ = m , ξ = m , · · · , ξ = m ) % þ k# ···+m = m −m n
1
n
1
1
1
1
X
P (ξ1 = m1 ) =
2
X
=
(m2 ,···,mn ): m2 +···+mn =m−m1
=
2
n
1
2
(m2 ,···,mn ): m2 +···+mn =m−m1
1
2
n
n
P (ξ1 = m1 , ξ2 = m2 , · · · , ξn = mn )
m! n p m1 p m2 · · · p m n m1 !m2 ! · · · mn ! 1 2
m! pm1 (1 − p1 )m−m1 m1 !(m − m1 )! 1 m2 mn X (m − m1 )! p2 pn × ··· m2 ! · · · m n ! 1 − p 1 1 − p1 m +···+m =m−m 2
1
n
m1 m1 = Cm p1 (1 − p1 )m−m1 .
rstu û Evw x ø 2)y ý õ % Ez{ s m E
p2 pn +··· + 1 − p1 1 − p1
|} %~E "þ # L1
%
m−m1
j j P (ξk = j) = Cm pk (1 − pk )m−j ,
=
1 − p1 1 − p1
P (ξk = mk ),
m−m1
ÿ
j = 0, 1, · · · , n ,
=1
k = 1, · · · , n .
(4.2.9)
k # M (m; p , p , · · · , p ) 0 k B(m; p ). 0 N no m +m ≤ m % >?@ w m , m , pq P (ξ = m , ξ = (3) %; u m ) n
1
2
n
k
1
2
1
2
1
1
2
2
X
P (ξ1 = m1 , ξ2 = m2 ) = =
X
(m3 ,···,mn ): m3 +···+mn =m−m1 −m2
(m3 ,···,mn ): m3 +···+mn =m−m1 −m2
=
P (ξ1 = m1 , ξ2 = m2 , · · · , ξn = mn )
m! n p m1 p m2 · · · p m . n m1 !m2 ! · · · mn ! 1 2
m! pm1 pm2 (1 − p1 − p2 )m−m1 −m2 . m1 !m2 !(m − m1 − m2 )! 1 2
0"1 % x / !,
P (ξi = mi , ξj = mj )
# LM¡
¢3£)¤
)¥ ¦3§)¨ ª0 M (m; p , p , · · · , p ) n = 3 ) i © 0" (ξ , ξ ) M (m; p , p , 1 − p − p ). «¬ (4) %®3¯)°±² ¡ JK³0 M (m; p , p , · · · , p ) k n = k + 1 ¡"´ B(m; p) µ M (m; p, 1 − p). «¬ (5) %®¶·¸¹º»H%¼ K0"½¾¿ N no m + · · · + m = % >? ·P @ w C (m , · · · , m ), · m−m 138
n
1
1
2
2
n
3
n
1
1
2
2
1
2
n
2
2
1
2
n
n
P (ξ1 = m1 , ξ2 = m2 , · · · , ξn = mn ) P (ξ1 = m1 ) m2 mn (m − m1 )! p2 pn ··· , = m2 ! · · · m n ! 1 − p 1 1 − p1
P (ξ2 = m2 , · · · , ξn = mn |ξ1 = m1 ) = =
m1 m2 m! mn m1 !m2 !···mn ! p1 p2 · · · pn m1 m! m−m1 m1 !(m−m1 )! p1 (1 − p1 )
« ¬ (2) ® 2 vw xÁ y Âà E 2 %ÄÅ ¡ r z{À s §4.2.3 ÆÇÈÉÊË"ÌÍÎ uÏ ³Ð «¬ 0 Ñ ³ xÒÓ ¡ &'3Ô)( (ξ , ξ ) %*+ÕÖ×w u p(x, y), s 1
2
Z
F (x, y) = P (ξ1 < x, ξ2 < y) =
t © 0
ξ1
ξ2
% / !,!Ø u F1 (x) = F2 (y) =
ÙÚÛ
Z
Z
x
p1 (x) =
∞
∞
Z
y
p(u, v)dudv, −∞
(x, y) ∈ R2 .
p(u, v)dudv,
x∈R,
(4.2.10)
p(u, v)dudv,
y∈R.
(4.2.11)
−∞
x∈R;
p(x, v)dv,
−∞
−∞ −∞ Z ∞Z y −∞
Z
x
p2 (y) =
Z
∞
y∈R.
p(u, y)du,
(4.2.12)
Ý R(4.2.10) EÀ s t © 0 Ù (4.2.12) E kÞß F%(x)×=w p (x)p À (u)du, s ξ %xÕ∈ ÖR×. w .áàâ0 p (y) À s ξ %ÕÖ×w ¡"
!Øã u ξ ξ % / ÕÖ ¡ ¿ l Fäåæçèé n ê + Ë ÙÚ n &'Ô ( ξ , · · · , ξ %*+ÕÖ×w u p(x , · · · , x ), Ü ¹ Në 1 ≤ k < n, k &'ìÔí( ξ , · · · , ξ % / ÕÖ×w u Ë Ü ¹ 0
−∞
p1 (x) ≥ 0, p2 (y) ≥ 0,
x −∞
1
1
1
1
p1,···,k (x1 , · · · , xk ) =
∞ −∞
···
Z
1
1
2
2
2
n
Z
−∞
∞ −∞
1
n
1
k
p(x1 , · · · , xk , uk+1 , · · · , un )duk+1 · · · dun , (4.2.13)
î3ï)ðñòóôðñ
§4.2
1 2 (x , · · · , x ) ∈ R . õ 1
% k / ÕÖ×w ¡ Aö 3 ×w ÷ õ k /ø , ×w ¡ ù 4.2.5 ú x &'3Ô)( (ξ , ξ ) %*+ÕÖ×w p(x, y) Ùû E k = 0"ü ø ØL ξ ý ξ % / ÕÖ×w ý /ø , ×w ¡ 7 Ë i (4.2.12) Eþ 1
k
k
1
1
p1 (x) = p2 (y) =
Aö / ÕÖ×w RæM F1 (x) =
Z
2
139
/ ÕÖ 2 (4.1.7) 4.1.3 k
2
∞
p(x, v)dv =
−∞ Z ∞
p(u, y)du =
−∞
x −∞ p1 (u)du Ry −∞ p2 (v)dv
=
Z
1 0
Z
1 0
1 (x + v)dv = x + , 2
x ∈ (0, 1) ; (4.2.14)
1 (u + y)du = y + , 2
y ∈ (0, 1) . (4.2.15)
Rx
1 0 (u + 2 )du = Ry 1 0 (v + 2 )dv =
1 2 2 (x + x), 1 2 2 (y + y),
0<x≤1;
Eÿ 0 / ÕÖ×w ÷ i * +ÕÖ×w Þ ¡ (4.2.12) ý (4.2.13) s 1 J ¡ ×w q(x, y) s u x ù 4.2.6 ü « 0 Ù Ô (ξ , ξ ) 6 ÕÖ Ë F2 (y) =
=
0
1
q(x, y) =
x+
1 2
y+
1 2
,
2
0 < x, y < 1 ?
7 Ë å æ q(x, y) s x Ô (ξ , ξ ) ÕÖ×w ¡ JK L ξ ý ξ / ÕÖ×w Ù (4.2.12) E k = ¡ û 4.2.5 ý û 4.2.6 2 Ô (ξ , ξ ) ÕÖ×w Ý Jà0 s ξ ý ÕÖ×w à¡ r Àÿ ËÊÍÎ!"ÍÎ#$% ¡ ξ / ¿ & ' ä þ 0 ÙÚ (ξ , · · · , ξ ) s n ()* Ô 0 Ü ¹ 132 ë+ k i , -./ k ()* Ô 0"Ý1 ÕÖ ÷ i (ξ , · · · , ξ ) Õ s 345 0267 , ξ , · · · , ξ s Þß8 à pq9: ¿ Ö Þ 2¡ À s ()* ¡ = * û n ()*, 0 Ô (ξ , · · · , ξ ) ; < > Ù 6Ë u ? : (0, 1) ¿ @ * p ù 4.2.7 ú {Ω, F, P } q 9: 0A 1
1
2
2
1
2
1
2
1
n
1
1
1
»
n
n
n
∀ ω ∈ (0, 1) , u ( )*, 0 s x Ô U (0, 1), GH þK 0 ÙÚ ξ , · · · , ξ s Þß8 à pq9: ¿ n 0OG PG
- s ()*, Q0 (ξ , · · · , ξ )
ξ1 (ω) = ξ2 (ω) = ω,
B ξJ -J C·ÕÖD×Ewø¡F (ξ , ξ ) I s 0 i ¿& ' äJK LMN , 0 Ü ¹ s n ()* Ô ¡ ξ1
1
2
2
1
n
1
n
¢3£)¤
140
¥)¦3§)¨
ÆÇÈÉÊËRSÌRSÍÎ T ö U ÕÖ 0 JK VW n ()* Ô XYøF0Z ÷ xÒÓ u û ¡ ÙÚ N a < b, · P (a ≤ ú x(Ü )¹ *T Ô (ξE , ξ ) [ \ ÕÖ u p(x, y), E VW ξ 8XY a ≤ ξ < b ξ < b) > 0, ö (4.2.12) 06 (4.2.6) Â] XY ø FË §4.2.4
1
2
2
1
P (ξ1 < x, a ≤ ξ2 < b) P (a ≤ ξ2 < b) Rx Rb Z x Rb p(u, v)dudv p(u, v)dv a = du . = −∞R ba Rb −∞ a p2 (v)dv a p2 (v)dv
2
P (ξ1 < x |a ≤ ξ2 < b) =
ÙÚÛ
Rb
p(x, v)dv p1 (x|[a, b)) = Ra b , p (v)dv a 2
(4.2.16)
x∈R,
Eÿ p (x|[a, b)) À s ξ 8XY a ≤ ξ < b Â] XY ÕÖ×w ¡ ^_ ·` s Ë ? : [a, b) a Öbc 0 Ò Ó ¡ed 8ú a = y, b = y + ∆y, 1 f ∆y > 0, Ýú p (y) > 0, 5 ³ ∆y → 0 Ò Ó ¡ i (4.2.16) Eþ
Ü ¹
(4.2.16)
1
1
2
2
P (ξ1 < x |y ≤ ξ2 < y + ∆y) = =
· ÙÚ Në
c s
(4.2.17)
Rx n −∞
1 ∆y
1 ∆y
R y+∆y
E , u
gh
−∞
o
y
p(u, v)dv du
y
p2 (v)dv
R y+∆y
1 ∆y→0 ∆y lim
u ∈ R,
R x nR y+∆y
Z
1 lim ∆y→0 ∆y
Z
y
p2 (v)dv
.
(4.2.17)
y+∆y
p2 (v)dv = p2 (y) . y
1 ∆y→0 ∆y
lim
y
R y+∆y
o p(u, v)dv du
R y+∆y y
p(u, v)dv
i80 Ü ¹Àjk·
y+∆y
p(u, v)dv = p(u, y) . y
P (ξ1 < x | ξ2 = y) =
Z
x −∞
p(u, y) du , p2 (y)
l 4 ¿ l ç m "0 ½¾¿Mn Ù ] Þ â Ë
x∈R.
(4.2.18)
î3ï)ðñòóôðñ %×o w 4.2.1 ÙSÚ xSp(p)p*pp Ôq 0 Q0
§4.2
À s
ξ1
p1 (x | y) =
8XY
(ξ1 , ξ2 )
p(x, y) , p2 (y)
pp ÕSÖ u
x∈R,
Â] XY ÕÖ×wr ÙÚ
ξ2 = y
p2 (y | x) =
p(x, y),
p(x, y) , p1 (x)
p1 (x) > 0,
» G
141 p2 (y) >
(4.2.19)
»×w
x∈R,
(4.2.20)
Â] XY ÕÖ×w ¡ 8 X Y ξ =x st Ë ½¾¿ 0 i (4.2.18) Eþ 0 p (x | y) s ÕÖ×w 0 ÝNë x ∈ R, ? : (−∞, x) ¿ N u uø À s XYøF P (ξ < x | ξ = y). p (u | y) 8 v + ËwXY ÕÖ×w s ÕÖ×w 09k ÷
j G noÕÖ×w xX Hy ¡ ù 4.2.8 ú Ô (ξ , ξ ) ÕÖ u − x − y), x, y ≥ 0, x + y < 1 . Õ Ö×wr (2) ξ 8 ξ = QXY ÕÖ×w ¡ L Ë (1) ξ 8 ξ =p(x, y)Q= X24y(1 Y z Ëw{ Ñ [\ (4.2.12) E 0 L p ( ) ý p ( ): R R À s
ξ2
1
1
1
1
1
2
2
1 2
1
2
1
1 1 2
2
1 2
1 2 2
1 ∞ 1 1 1 1 2 2 = −∞ p 2 , v dv = 24 0 v 2 − v dv = 2 ; 1 R R ∞ p2 12 = −∞ p u, 12 du = 12 02 12 − u du = 32 .
p1
| ø Ø i JK
(4.2.20)
ý
(4.2.19)
p(x,y) = 2p 21 , y = 48y 12 − y , p1 ( 12 ) = p(x,y) = 23 p x, 12 = 8 21 − x , p2 ( 12 )
p2 (y | 12 ) = p1 (x | 21 )
Eþ 0
R
1 2
R
1 2
0
1 2 ; 1 2 .
k ÷ 0
- s ÕÖ×w ¡ E} l n ÕÖ B U ÕÖ ý XY ÕÖÂ: ~ ¡ r (4.2.19) ý (4.2.20) ~ · Q ÷ ö 5 L ÕÖ ¡"³ û > Ë ù 4.2.9 ú λ > 0, , ζ ÕÖ×w u p (x) = λ xe , x>0, ? : ¿ Ör, η C Õ(0,Ö×ζ) w ¡ DEøF0 L Ë (1) Ô (ζ, η) Õ , z (2)Ë i ¬ + þ 0wη8 ° Þ ζ = x XY ] 0 η J · XY ÕÖ p (y|x) = , x > 0 , k ÷ (ζ, η) ÕÖ×w u p(x, y) = p (x)p (y|x) = λ e , 0
p2 (y | 12 )dy =
2
1
0
p1 (x | 21 )dx = 1 ,
−λx
2
1
6 η C w u
p2 (y) = λ
R∞
−∞
2 −λx
2
p(u, y)du =
Poisson
øF
R∞ y
P (λ).
λ2 e−λu du = λe−λy ,
y>0,
1 x
¢3£)¤
142
¥)¦3§)¨
, MN Hp s pq ä f p 0 à MN Hp 0 , MN Hp øö ¡ {Ñ ° , LMN Þß ¡ % 4.2.1 c ú
ξ , · · · , ξ s Þß8 y à pq9: ¿ n , 0 øFm U øF u06 §4.2.5
1
n
F (x1 , · · · , xn ) =
n Y
Fk (xk ) ,
Ü ¹À ã
LMN¡ þK 0 (4.2.21) E |} m c k=1
∀ (x1 , · · · , xn ) ∈ Rn ,
P (ξ1 < x1 , · · · , ξn < xn ) = P
n T
½ Y ÙÚ
(4.2.21)
(ξk < xk ) ,
1 } m c Q P (ξ < x ), k ÷ (4.2.21) E m c Ë"Në (x , · · · , x ) ∈ R , ½ Y (ξ < x ), · · · , (ξ < x ) - LMN¡ | i ¾ , ×w ä þ 0 þ r ½¾ m c Në n Borel B , · · · , B , ½ Y (ξ ∈ B ), · · · , (ξ ∈ B ) - LMN¡ T ö ¿ l ½¾ 0" N 6 Mé Ë ÙSÚ (ξ , · · · , ξ ) s n p pp*pp Ôqp0pppø Ø u {a }, · · · , {a % o 4.2.2 » , ξ , · · · , ξ LMN XY s n
k
k=1
k
1
n
n
k=1
1
1
n
n
1
1
1
n
1
1
n
n
(1) i
n
n
n Y (1) (n) (k) P ξ1 = a i1 , · · · , ξ n = a in = P ξ1 = a ik , k=1
∀
(k) a ik
∈
(k) {ai },
k = 1, · · · , n.
(4.2.22)
N c ()* Ô0" Fä s Ë ÙÚ (ξ , · · · , ξ ) s n ()* Ô0 » , ξ , · · · , ξ % o 4.2.3 LMN XY s (ξ , · · · , ξ ) ÕÖ m c
n U ÕÖ y u ¡ st Ë P ÷ n = 2 Ò . uû ¡ i)Þß 4.2.1 þ 0x , ξ B ξ LMN 0G PG
ø Fm c
U ø F y u06 1
1
n
1
n
n
1
F (x, y) = F1 (x)F2 (y) .
(4.2.23)
p(x, y) = p1 (x)p2 (y) ,
(4.2.24)
ÙÚ
ÕÖ m c
x U ÕÖ y u06 Ü ¹¡ HN ¢
2
- ·
(x, y) ∈ R2 , Rx Ry Rx Ry F (x, y) = −∞ −∞ p(u, v)dudv = −∞ −∞ p1 (u)p2 (v)dudv
(n) i },
î3ï)ðñòóôðñ
§4.2
£ þ
143
Rx
Ry
p (v)dv = F (x)F (y) , 3 Ù Ú s x ¤(¤)¤*¤¤ Ô2¤0"Ý n o  ¤ ¤ L ¤ M N ¡ ξ B ξ 0 (ξ , ξ ) (4.2.23) ¥ 0 Ü R¹ N R¢ (x, y) ∈ R , - · =
1
−∞
2
p1 (u)du
−∞
2
1
1
2
2
2
x y p(u, v)dudv = F (x, y) −∞ −∞ Rx Ry = −∞ p1 (u)du −∞ p2 (v)dv =
= F1 (x)F2 (y) Rx Ry p (u)p2 (v)dudv , −∞ −∞ 1
^_¿ ¥x } 06 M (4.2.24) ¥ ¡"¿ l JKçèé n ê ¡ 8j & À s ¦ûL¬MN f 0Gr©§¨ª ³l é4M« N , û > ¡ ûÙ ³0 û ¡ 4.2.1 f Ý8 0 m± ¥ pÙÚ = p p ° ܬ ξ B l ξ4 VW é ¯ ° 0 ] XYøF0á
³²´ ® ˹ ξ 8 Þ MξN¡ ër Ü L à U x û X> Y f XYøF- B ¾µ¿ ¶· c ør F 0 üξ B «ξ¬ f ¹ · > Ô (ξ , ξ ) 5 à º» ¼0½1 f 3 ¼ ¿ õ w¾ 0, ¯¿ x ¼ ¿ õ w˾ 81.¸ f À x ¼á0 ø Ø ö ξ ý ξ ÿÁ x ¼ ¿ kõ w¾ ¡ Ü ¹ 0eG · ¹ÂÀ Q0 Á )0 Ä ¹ÂÀ Q0
øFÃ » Ùû
Á ¡ øF÷ Ã ûz Ùû 4.2.1 k f s LMN 0á û 4.2.2 f ξ B ξ » 4.2.2 k k 0 4.2.1 ξ B ξ © H ¡ Å v + é 0 û 4.2.6 f ÕÖÀ m c
x U ÕÖ y u0Gk ÷ ܬ x , LM N ¡ i Þß 4.2.1 ©ª ç þ 0 ÙÚ n LM, N ¡ ξ , · · · ,rξ Ç Lä MN 0 ܯ¹)°
± ²Â ¡ f Æ ëà k (2© ≤Ä k < n) ° Ù , ] Ç ä "0 Ë Ù Ú s %o 4.2.4 L © ξ È, · · · , ξ 9 > n Lf MNØÊ · , 0 AËýÌ A»sÍ {1, · · · , n} x x ø Ø u k Ë ý k Ë É Borel Î 02×1 w ø f ý g Ïk 0 ý ηk = f (ξ , 0 i ∈ A ë ) ý s LMN , ¡ η = g(ξ , j ∈ A ) x ÐÑ 4.2 ÒÔÓÔÕÔÖÔ×ÔØÔÙÔÚeÛe×ÔØeÜeÝeÕeÖÔ×eØeÞ ßÔàÔáâäã ÙÔ×ÔØÔåÔÝ 1
2
i· ·j
ij
1
1
1
2
1
2
1
1
1
j
2
n
n
1
1
2
2
2
1
1
2
2
2
2
1
i
1
2
1.
2.
(ξ1 , ξ2 )
ξ1 \ξ2
æeçeè
0
1
2
3
4
5
0
0
0.01
0.03
0.05
0.07
0.09
1
0.01
0.02
0.04
0.05
0.06
0.08
2
0.01
0.03
0.05
0.05
0.05
0.06
3
0.01
0.02
0.04
0.06
0.06
0.05
ÙÔ×ÔØÔåÔé
ÙÔ×ÔØÔåÔÞ
(1) P {ξ2 = 2|ξ1 = 2}, P {ξ1 = 3|ξ2 = 0}; (2) η1 = max(ξ1 , ξ2 )
(3) η2 = min(ξ1 , ξ2 )
(4) ζ = η1 + η2
Ùe×eØeåeé
¢3£)¤
144
ßÔàÔáâäã
3.
ñ
ÙÔêÔëÔìÔíÔÝ
1 xk1 −1 (y − x)k2 −1 e−y , Γ(k1 )Γ(k2 )
p(x, y) =
îÔï 4.
(ξ, η)
ÙÔìÔíÔòÔóÔÝ
k1 > 0, k2 > 0, 0 < x ≤ y < ∞.
(ξ, η)
æÔçÔè
(
p(x, y) = (1)
õÔó
æÔç ð ÙÔÚÔÛÔ×ÔØÔìÔíÔÞ ξ
η
Ae−(2x+y), 0
Ôî ô ÙÔÚÔÛÔ×ÔØÔé
x > 0, y > 0, .
A; (2) P {ξ < 2, η < 1}; (3) ξ
ßÔàÔáÔöÔã ÷ÔìÔí ø ùÔúÔûÔü ýÔÙÔþÔÿÔ×ÔØÔÞ æÔç ÙÔæeìÔçíÔ òÔ óÔ Þ ÔíÔÝ Ù ÔÒÔÓ ÷Z (5) p(x|y); (6) P {ξ < 2|η < 1}.
5.
η
6.
12.
η
a>0
a
1 √ 2π
ßÔàÔáÔöÔã
8.
11.
(0, ξ)
x > 0,
a
7.
10.
(4) P {ξ + η < 2};
ξ
p(x) = λ2 xe−λx,
9.
¥)¦3§)¨
(ξ, η)
ÒÔÓ è ð
e−
ÙÔêÔëÔìÔíÔòÔóÔÝ
p
dx ≤
−a
1 + xy , 4
p(x, y) =
1 − e−a2 .
|x| < 1
$ !"ÔÙÔÞ ) 1 ' ÔýÔÙ(
!"#
ð
x2 2
ÔÙ eÞ
|y| < 1.
! "&%ÔùÔú −1 ð ×ÔØ ø ζ = ξη. ÒÔÓ è ξ, η, ζ !" #*+!Ô " Þ ß ξ Ý,Ô- ÙÔàÔáÔöÔãOÒeÓ ξ ð.ÔàÔáÔöÔæã8!9 " 0/ 12 ξ ð4356!"ÔÞ ß ξ Ý,-7 c ÙÔàÔáÔöÔã η ùÔúÔ×ÔØ F , (ξ, η)$ è ÙÔêÔëÔ×ÔØÔÞ ßÔàÔáÔöÔã $ η ùÔúÔ×ÔØ F , : F (x) ;Ô< Ù=Ô×>?@A è . x ∈ R, %Ô÷ P (η = x) = 0. # B7 n (n ≥ 2) C à á2â ãBDBEBF'BBGBHI ÞKJ JLBB. (x , · · · , x ) ∈ R ,e % ÷ P (ξ = x , · · · , ξ = x ) = 0, àeá âã (ξ , · · · , ξ ) Ùeêeëe×eØeòeó M N > ; < (OP èQR ýS ï Ù T U ). V Q
ñ
ξ
η
ξ2
ξ, η
η2
η
η
η
1
n
13.
1
1
n
n
1
ñ
s
a) b)
1+ xi , p(x1 , · · · , xs ) = i=1
ÔÒ Ó è XÔß Ô C àÔáâäã
p(x , · · · , x ) $ 1
s
s
.
s
(ξ1 , · · · , ξs )
ñ
*+!"Ôé
îÔô
1 2
≤ xi ≤ 12 , i = 1, 2, · · · , s;
0,
ï
Y
WÔìÔíÔòÔóÔé
(1) ξj ∼ U (− 12 , 12 ), j = 1, · · · , s ; (2)
−
2 ≤ q < s, ξ1 , · · · , ξs
n
.
ÔÝ ìÔíÔòÔó æ ÒÔÓ è ÔàÔáÔöÔãÔþ*+ !"eé
p(x1 , · · · , xs )
.
q
(3) ξ1 , · · · , ξs → − (1) → − (2) (4) ξ = (ξ1 , · · · , ξq )τ , ξ = (ξq+1 , · · · , ξs )τ , 1 ≤ q < s,
s (1) (2) 1 + Q xi , → − → − p ξ |ξ = i=1 0,
ñ
−
1 2
îÔô
:
≤ xi ≤ 12 , i = 1, 2, · · · , s; .
n
§4.3
14.
Z\[^]\_a`abacadðñ
145
JÔðeDÔÙÔ×ÔØÔ÷ * fÔÙ geÞ V F (x, y) $ àÔáâäã (ξ, η)æ ÙÔ×ÔØÔòÔó G(x) h H(y) ×1 $ G(x) h H(y) $ ;<ÔòÔó Ò F (x, y) M $ ; <ÔÙÔÞ
ξ
h
η
ÙÔÚÔÛÔ×ÔØÔÞwñ
i jklkmknkokpkqkrks k axayaza{a|a}a~aa Fa4 vawaa|a aF
5 vaw tau a
§4.3
@
aaaaa aaa a n |aaaaaaaazaa^\ (ξ , · · · , ξ ) a aa ¡ a¢az £a¤ 4.3.1 ¥ D ¦ n | Borel §a4¨ 0 < L(D) < ∞, ©aª §4.3.1
1
p(x1 , · · · , xn ) =
1 , L(D)
n
(x1 , · · · , xn ) ∈ D
¦a«a¬aa® z n |a}a~aaa¢ ¦ n |a ¡ a¢ 4¯a¦ U (D). °\±a²a³a´aµa a¶ n |aa^\ (ξ , · · · , ξ ) a a¢ Borel § B ⊂ D, º 1
P ((ξ1 , · · · , ξn ) ∈ B) =
n
L(B) L(D)
n
|a
(4.3.1)
U (D),
·a¸a¹
.
n
¼a½^¾\4¿ a^\ (ξ, η) a a¢ a zaÄaÅ «a¬aÆ (2) ÇaÈ ³ η = y (−1 < y < 1) zaÉaÊa U (D), ÀaÁa (1) ξ à η zaÉaÊ «a¬a ξ Ë ÂÌ (ξ, η) zaÍa «a¬aa®a¦ »
4.3.1
¥
D = {(x, y)| x2 + y 2 < 1}
1 π
x2 + y 2 < 1 .
ÎaÏ (1) Ð |x| ≥ 1 Ña p (x) = 0; ¿aÐ |x| < 1 Ña4º R R p (x) = p(x, v)dv = = ÒaÓ ¸a©aÔ µa p(x, y) =
1
1 ∞ −∞
,
√ 1−x2 1 √ − 1−x2 π
2 π
p
2 π
√
1 − x2 .
2
1 − y , |y| < 1 . Õ aÖa×aØaÙ tau Â4¼a½^¾ Õ za ¡ a¢azaÄaÅaa¢aÚ ²a|a ¡ a¢ ³ η = y (−1 < y < 1) zaÉaÊa ξ zaÉaÊ «a¬a¦ (2) ÇaÈ p2 (y) =
ª Ï Ñ
ξ
aaÛaÜ
√2 2 , P1 (x|y) = p(x,y) p2 (y) = 1−y p p 2 2 [− 1 − y , 1 − y ]
|x| ≤ |y| ,
Õ za ¡ a¢
ÝaaÞaßaa v waèa|aâaãaa¢ tauaà Ç ±aáavawaa|aâaãaa¢ 4äaåaÇaæaç a
§4.3.2
|
é^ê\ë
146
£a¤
4.3.2
¥
a 1 , a2
¦a×a®a
¿
σ1 > 0, σ2 > 0,
|r| < 1,
ì\í^î\ï
©aª
1 √ p(x, y) = × 2πσ1 σ2 1 − r2 −1 (x − a1 )2 2r(x − a1 )(y − a2 ) (y − a2 )2 exp − + ,(4.3.2) 2(1 − r2 ) σ12 σ1 σ2 σ22
¦ð«ð¬ðð® zðð|ð}ð~ðð𢠦 ð|ðâðãðð¢ 4¯ð¦
N (a1 , a2 ; σ12 , σ22 ; r),
ñóò
2
(x, y) ∈ R .
tau a å öa÷ R R p(x, y)dxdy = 1 . a z a ø ù a ² a ú a û ^ ù ü ça ø 6.1 ò\Èaýaþaÿ zaaø a® p(x, y) â ãa tauaà a|aâaãaa¢ N (a , a ; σ , σ ; r) zaÄaÅ «a¬a Ça¹ a ¢ z ò a Ú à a taua ôaõ
p(x, y) > 0 ,
∞ ∞ −∞ −∞
1
u=
p1 (x) =
Z
∞
4ä
p(x, y)dy =
−∞
t=
v−ru √ , 1−r 2
u2 1 e− 2 2πσ1
x−a1 σ1 ,
2 2
v=
y−a2 σ2
Z
1 √ 2πσ1 1 − r2
,
2 u − 2ruv + v 2 exp − dv , 2(1 − r2 ) −∞ ∞
" #) 2 1 v − ru 2 √ exp − +u dv 2 1 − r2 −∞ Z ∞ (x−a1 )2 t2 u2 1 1 1 2 e− 2 dt = √ e− 2 = √ e σ1 . ·√ 2π −∞ 2πσ1 2πσ1
1 √ p1 (x) = 2πσ1 1 − r2 =√
2 1
2
Z
(
∞
± aa ξ zaÄaÅaa¢ ²a|aâaãaa¢ N (a , σ ). µ η zaÄaÅ ð¢ ð ² |ðâðãðð¢ N (a , σ ). ±ðú Öð×ðØðÙ tðu  ð|ðâðãðð¢ðz ðúðÄðÅð ¢! ²aa | âaãaa¢ " Ç Íð «ð¬ p(x, y) ò$#ðº %ð® r, ¿ ðúðÄðÅ «ð¬óò ! & º %ð® r, ª´ Ía «a¬ p(x, y) Ú'^° ÿ zaúaÄaÅ «a¬ z(a/³ 041 æaçaå) $(*aú %a® z tau å+, 4ñ^ò %a® r -.aþ ξ Ã η ¬a Ú 3 Áaýða® p(x, y) Ç45aç Õ z6a7 4Öa× Õ ÒaÓ Õ ç z 2 ¶ tau º 1
2
Z
± a÷ þ
2 1
2 2
p(x, y)dy dx −∞ −∞ −∞ −∞ Z ∞ Z ∞ 1 (x − a1 )2 = p1 (x)dx = √ exp dx = 1 . σ12 2πσ1 −∞ −∞ ∞
(4.3.2)
Z
∞
p(x, y)dxdy =
8 Èaý z a®
Z
∞
p(x, y)
Z
∞
z( ²aú «a¬aa®a
ì í^î\ï9: ; \ ý ÉðÊ «ð¬a ° ¹ ðúaÄðÅ «ð¬ ÒaÓ Õ ç z 2 ¶ a < Ì >>? ¹ 0, @a¸ A y ∈ R, ! º §4.4
p(x, y) 1 =p exp p1 (x|y) = p2 (y) 2π(1 − r2 )σ1
(
µa Â
η
ÇaÈ ³
p1 (x)
(x − a1 − r σσ12 (y − a2 ))2 σ12
" ^ ñ ò z y aÖ à È ³az7 ª Õ 8 Â ²a|aa â ãaa¢ N (a1 + r
147
ξ
ÇaÈ ³
η=y
)
,
=
p2 (y)
x ∈ R.
Ñ zaÉaÊaa¢
σ1 (y − a2 ), σ12 (1 − r2 )) . σ2
(4.3.3)
σ2 (x − a1 ), σ22 (1 − r2 )) . σ1
(4.3.4)
Ñ zaÉaÊaa¢ ²a|aâaãaa¢
ξ=x
N (a2 + r
Õ 8 BC ¦ N (a , σ ) = N (a , σ ), D B Ã ξ = η zaÄaÅa · ¢/ a Ï Ñ Ía a « ¬a¹ aÄaÅ «a¬ zE6 0a¿ ξ Ã η /FGH ± a Ç ²a³ a´ ÕI þ%a® r J# ´ K ²L J# ´ åaÇ a²M ò NOa a¶
r = 0,
2 1
1
PQ
2 2
2
4.3
RTfhgSTUWVYX (ξ, η, ζ) ZT[T\Tfh]Tg ^ D = {(x, y, z) : x + y + z ξ `hihjhchdhk (2) ξ lhmhn η, ζ `hohphqhrhshthu 2. RhShUVvX (ξ, η) whqhr 2
1.
1 x2 + y 2 p(x, y) = exp − 2π 2
2
xy 1− (1 + x2 )(1 + y 2 )
2
< 1}
_T`TaTbTcTdTe
(1)
−∞ < x, y < ∞.
,
h` ihjhqhr{v|h}T~TuTT yTTT
TT xhyhzh 3. R ξ ξ |hShUhhXhe ζ = ξ + ξ , ζ = ξ − ξ . ζ , ζ |hhhhh` }h~hShUhhXhe ξ ξ |h}h~hfhShhUh hXhu 4. (ξ, η) Zh[hhh}h~hchd (4.3.2), ξ + η ξ − η hhhh`hhhohpTu xhy e h ξ + η 5. R ξ η hhhhchdh`hShUhhXhehqhrhshthh T¡ 0 ¢hwhh£h¤hthu ξ − η hhhhehShUhTX ξ, η, ξ + η, ξ − η ahZh[h}h~hchdhu 6. (ξ, η) Zh[hhh}h~hchd N (a, b, σ , σ , r), ¥ D(λ) h¦h§h¨h©h`ªv« xhyhz
1
ξ, η 2
1
1
1
2
1
2
1
2
2
2
fhgh¬h
2
2
(x − a)2 2r(x − a)(y − b) (y − b)2 − + = λ2 2 σ1 σ1 σ2 σ22 P {(ξ, η) ∈ D(λ)} .
® ¯°±°²°³°´°µ ° ¶¸·º¹¼»¸½¸¾¸¿ ¸ J ®¸ÀÂÁ Ç ¸½¾ ^ J a®¸ÃÅÄ ¶ ³a´ Ç ²aúaÆÇ Ü Õ J n úaaa À¼ÈÉ (ξ , · · · , ξ ) a ²aú §4.4
1
n
Ê a
ξ1 , · · · , ξn n
é^ê\ë
148
ì\í^î\ï ³a´ ) a
\ Ë µÌ a®ÀËÈÉ ζ =: g(ξ , · · · , ξ Ä Æ¶ Ç g(xÕ , · ·a· , x a) n ¶Ê ·Borel Ã Î ζ ©a¦ ± n úaaa Jaa®ÀÏÐ Ñ n Ê ÇÍ Ü J à a^\ (ξ , · · · , ξ ) Jaa®Ã ¶· JAÒa ° (ξ , · · · , ξ ) J ÍaÓa¢ Áaýañaa® J Óa¢ à J *¸Û ù 8J ®ÀÂÜÄ ÂÅÄ ¶ ξ , · · · , ξ ×¸Ô¸Õ¸Ö ò »¸× )¸Ø¸Ù¸Ú ú ¸ n ÝÞß^ ò Jàá 7 ÀÈÉ ζ =7 ξ + · · · + ξ a n ÝÞß^ò Jâàá 7 Æ ¿ ζ = max{ξ , · · · , ξ } a ã ? àá Æ äa¹ ζ = , k = 1, · · · , n * ·a ÝÞß^ò JàáaÇâàá^ò åæJç èÃTéêaÑÀTÄ ¶ ª (ξ, η) ëìí 1
n
1
1
n
1
n
n
1
1
1
n
n
n
k
ξk ξ1 +···+ξn
JîïðñÀÈÉ p ρ = ξ + η , θ = arctan ò¸Ó¸B¸ó¸ë¸ì¸í ð¸ñô í Jõ¸ =ö¸ïJ 7 À0¹ ó (ρ, θ) ò¸ó¸ë¸ì¸í J¸ö¸ð¸ñà ò Ú÷ø ) ÓB Øù ρ = θ, ¿a¨ ø )ØùúÊûüý þ (ρ, θ), äa¨ ø ) ¹ ° ó ¶· a ÍÿÓ Áaý (ρ, θ) J ÍÿÓ Ã ± JÜ µ ªaýÚà (ξ, η) J §4.4.1 ¶a · à ãa ¼J,à ¥ (ξ, η) ó úÊ û¶ üý þÀ ÿJ 7 § 7 ÿ ¦ ÿ {(i, õj) ó|i,j =0, 1, · · ·},ÿ äa¨ P (ξ = i, η = j) = p , Ä ζ = ξ + η, ÈÉ ζ J § Ð ®a§ À ä 2
η ξ
2
i,j
¨aº
P (ζ = k) = P (ξ + η = k) =
k X i=0
B ÀÄ ¶
ξ
Ã
i) = ai , P (η = j) = bj
P (ξ = i, η = k − i) =
k = 0, 1, · · ·(4.4.1) .
ó/FGH J ® 7 J û ü þ À4ä𨠦 , ÈÉ (4.4.1) 8 k X i=0
k X
pi,k−i ,
i=0
η
P (ζ = k) = P (ξ + η = k) =
=
k X
P (ξ =
P (ξ = i, η = k − i)
P (ξ = i)P (η = k − i) =
k X
ai bk−j ,
k = 0, 1, · · · .
(4.4.2)
a¤ 4.4.1 ¶·Î /FGH Jûü þJ=J Ó ©a¦%aÃaÁ=J ûü þ 6 8à B ÀWÄ ¶ %aÃðÁ= J û J Ó JÓ /6 À4¿ Î 8 ¶(4.4.2) a © ¦
ü þJ ÀÈÉ · ò Î ÿ · J=J Ó ©a¦Í ÛÓ J ! 6 à » 4.4.1 ¥ 0 < p < 1, û ü þ ξ à η / F G H À4ä ¨ ξ " ú Ý Ó#
úÝ Ó B(m; p), ÀaÁ ζ = ξ + η J Ó$ Ã B(n; p), η " i=0
i=0
§4.4
ì\í^î\ï9: ;
Ë Â¯
° 6 8
q = 1 − p,
P (ζ = k) = P (ξ + η = k) =
k X
149 (4.4.2)
%
ai bk−j =
i=0
= pk q m+n−k
k X
k X i=0
k−j k−i m−k+i Cni pi q n−i · Cm p q
k−j k Cni Cm = Cm+n pk q m+n−k ,
k = 0, 1, · · · .
(4.4.3)
ζ = ξ + η " úÝ Ó B(m + n; p). ±aú Ô(Ð Ñú Õ&2 ¶ × º ' À ÿ 6)* Ô À!+aÐ " À ±aá J%a® p ó ²aú Ã î, Õ
" úÝ Ó B(m + n; p). Ú3 ÷ 6587¸Ó8 à Poisson Ó8 Ï89 º8 68)8* · J Ô À 8 ä : a < ¸ Ì a ÿ ´ à ¸a¹úÊ;<ûüý þÀ ¶· ºa = 4.4.1 Ä ¶ (ξ, η) ó úÊ;<ûüý þÀ ÿ · J Íÿ «a¬> p(x, y), · ÿ · J= ξ + η ó ;<ûü þÀ?a 9 ºa«a¬aa® pξ+η (x) =
@A Â à Á
Z
∞
Z
∞
p(u, x − u)du,
J ÓBRC R F (x). ¶· º
−∞
ξ+η
p(x − t, t)dt =
−∞
∀ x ∈ R.
(4.4.4)
R∞ R x−u F (x) = P (ξ + η < x) = = −∞ du −∞ p(u, v)dv u+v<x p(u, v)dudv o R∞ Rx R x nR ∞ = −∞ du −∞ p(u, t − u)dt = −∞ −∞ p(u, t − u)du dt.
Jó Ó BC F (x) ó ñ^ò JDBEC F^ò J BC ÇaÛaÜ (−∞, x) Õ J ;<ûü þÀñHI Ä (4.4.4) ò JJú8å ÆLK 6ÓÀhMåN G À?O ξ + η (4.4.4) ò JJP8Ã B ÀÄQ ξ Ã η /FGH À?R (4.4.4) 8 > ±ò I À 6Ó
ξ+η
pξ+η (x) =
Z
∞
pξ (x − t)pη (t)dt =
Z
∞
pξ (u)pη (x − u)du,
¶·Î (4.4.5) 8T>HI BC Ò Ó (4.4.5) 8Àa a < ÌUaý ξ + η J ÓBC S
−∞
−∞
4.4.2
Z
pξ (x)
Ã
pη (y)
∀ x ∈ R.
J 6 8Ã
(4.4.5)
F (x):
x
F (x) = P (ξ + η < x) = pξ+η (s)ds −∞ Z x Z ∞ Z ∞ Z x = ds pξ (s − t)pη (t)dt = pξ (s − t)ds pη (t)dt −∞ −∞ −∞ −∞ Z ∞ Z ∞ = Fξ (x − t)pη (t)dt = Fξ (x − t)dFη (t). −∞
−∞
150
O Ú÷ Ä 6
é^ê\ë
R∞
ì\í^î\ï
F (x − t)dF (t). ¸ 6 Ó ù W J ¸ ¶ · stiltjes ( å Ç æ ç¸N¸O8V Û¸6¸Ó ), 8O8G Î 88 8 8Ï >V aÛ ù 8à S 4.4.3 ¶·Î
Ï À Ò Ó
F (x) = P (ξ + η < x) =
Fξ+η (x) =
Z
∞ −∞
Fη (x − t)dFξ (t) =
Z
−∞
∞ −∞
η
ξ
Fξ (x − t)dFη (t),
x∈R
(4.4.6)
T8> Ó88B8C F (x) Ã F (y) J8 6 ÀYX F =6 F ∗ F ; ¸B8 À Ç F = F = F ÑÀ?X F = F ∗ F, ä:Tañ> F Júè ! Ã ôaõ OGKZ ÓBC JÚè 6[ À Ä W 2¾ Â = 4.4.2 ÄQ ξ , · · · , ξ ó\] Ç P ú^ Æ Ç Ü Õ J n ú / F G H J û óÓBC F , · · · , F J ü6 þÀ?Raÿ · J= ξ + · · · + ξ J Ó F Â ξ
η
ξ+η
ξ
η
ξ
η
∗2
1
n
1
B À4Ð
n
ξ1 +···+ξn
ξ1
ξn
F = F ∗···∗F ; / F G H ξ ,···,ξ À ä:" P Ó F ÑÀ?_ 4 F = F ∗··· ∗F = F , 6 ñ^ò F T> F J n è ! Ã ` 4.4.2 aûü þ ξ , ξ , · · · , ξ /FGH (n ≥ 2), " % C λ > 0 Jb CÓ Ã4÷ À ξ + ξ + · · · + ξ " Γ(λ, n) Ó À?caD ñHI BC ó Â ξ1 +···+ξn
1
ξ1
ξn
n
∗n
ξ1 +···+ξn
∗n
1
1
2
2
n
pn (x) =
Ë Â ¶·aà ÒaÓ
åGÀ4Ð: ÷ Ð
n
(4.4.5)
λn n−1 −λx x e , Γ(n)
8d
p2 (x).
x>0.
"
e 0 < u < x ÑÀ?_ p (u)p (x − u) > 0,
p1 (u) = λe−λu ,
p2 (x) =
p1 (x − u) = λe−λ(x−u) ,
x > 0;
1
(
λ2
Rx 0
(4.4.7)
x − u > 0,
1
e−λu e−λ(x−u) du = λ2 xe−λx ; x > 0; x ≤ 0.
0
ú b CÓ 6ðÚ Õ&2 Q (4.4.7) 8aÇ n = 2 Ñ0 H À4ä:aØaÙ ¶·  a J C Ó À e ó Γ(λ, 2) Ó À4ÿ âfó % C λ > 0 J Poisson Ó gò J 2 ú ó b ( í h ÑaÜ J Ó Ã?ia k ú b CÓ J 6ó Γ(λ, k) Ó ÀD_ ¶¸·¸ . Ò Ó (4.4.5) 8¸À Ó¸p B(x)å =P (u)x= pe (x −, u)x>>00j8. k ñ ò¼À D8O % (4.4.7) 8aÇ n = k + 1 Ñ Ï0 H à k
λk k−1 −λx Γ(k) k
1
§4.4
ì\í^î\ï9: ;
151
l m n op úÊ;<ûüý þÀ ¶· _a = 4.4.3 ÄQ (ξ, η) ó úÊ;<ûüý þÀ ÿ · J Íÿ HI> ÿ · Jq ó ;<ûü þÀ?9_HI BC §4.4.2
p(x, y),
ξ η
p ξ (x) = η
@A Â ¶· d
Z
∞
J ÓBC
−∞ ξ η
|t|p(xt, t)dt =
Z
∞
|u|p(u, xu)du,
¶· _
−∞
F (x). Z Z ξ <x = F (x) = P p(u, v)dudv u η v <x Z Z Z Z = p(u, v)dudv + = = =
Z
Z
Z
u<xv, v>0 Z xv ∞
dv
0
∞
0 x
p(u, v)du +
−∞ Z x
Z
0
dv −∞ Z 0
∀ x ∈ R.
R
(4.4.8)
p(u, v)dudv
u>xv, v<0 Z ∞
p(u, v)du
xv
dv v p(tv, v)dt + dv −∞ −∞ Z ∞ |v|p(tv, v)dv dt.
Z
−∞
v p(tv, v)dt
x
Õ 6 VÓ ò I À ó J ÓBC F (x) ó ñóò$BJCDEF ò$J BC ÇðÛðÜ (−∞, x) J ÆrK 6Ó À å G ; < û ü þ À ñ H I Ä (4.4.8) ò JJP8å MN À?O (4.4.8) ò JJú8à ` 4.4.3 aûü þ ξ à η /FGH À" % C λ = 1 Jb CÓ À?sd JHI BC Ã Ë Â ¶· ÒaÓ (4.4.8) 8d p (x). t p (ξ, η) J Íÿ HI> p(u, v) = e , u > 0, v > 0, 8 6 8 B C ÷ иÀ t > 0 = xt > 0, 8e %8_ å8G8u (4.4.8) 8 ò¼J8v |t|p(xt, t) 6= 0, Ð8: −∞
−∞
ξ η
ξ η
ξ η
ξ η
−u−v
p ξ (x) = η
( R∞ 0
t e−xt−t dt = 0
1 (1+x)2 ;
x > 0; x ≤ 0.
wxyz{| }~ ù 8J BC À Á
½¾ P ù Ã!> p ½¸¾ À ¶· Õ ç ½¾ J óa ÷ Øù;< ù à ¶· aå çJ ó a (ξ , · · · , ξ ) ó n Ê8;8<8¸û¸üºý¼þ¸À98_ ÿ H I BC p(x , · · · , x ). i8a ζ = f (ξ , · · · , ξ ), j = 1, · · · , m, ÈÉ (ζ , · · · , ζ ) 9_ J ÿÓ §4.4.3
1
n
1
j
1
m
j
1
n
n
é^ê\ë
152
& _ ] À à À o ú j, ζ > û ü þ ÀV ò )d > þ ó Borel O Ì BC Ã4ñ.À ¶· )d ' 1 P-;<OJ- By C=f (x , · · · , x ), j = 1, · · · , m, j
j
j
1
i = 1, · · · , n. o ¡ B C 1 Ľ¾å%À6 m > n À¼D f Ï¢£¤¥¦ ¿© a m = n J§Ã? m < n À?OG¨ ζ = ξ , j = m + 1, · · · , n, C > m = n J§Ã \8ª8W À ¶¸·8« 8P8¬P8 ¡ Jûüºý þ8® 8¯ ¸
8 Ä 8 i P L Jia¶·Ã = 4.4.4 ÄQ (ξ , · · · , ξ ) ó n Ê;< û ü ýËþ À9_ ia¸
n ¬ Borel O ̹BC j
1
» : op
n
1
j = 1, · · · , n,
j
1
j
1
n
n
1
n
y1 = f1 (x1 , · · · , xn )
(4.4.9)
············ y = f (x , · · · , x ) n n 1 n x1 = h1 (y1 , · · · , yn )
············ x = h (y , · · · , y ) n n 1 n
,
(4.4.10)
°¹¿² ¬ h ÿ (y , · · ·B, yC ) ¾ _PÀ;<Á C À ÈÉûüý þ À?9_ HI j
1
q(y1 , · · · , yn ) =
n
(
p (h1 (y1 , · · · , yn ), · · · , hn (y1 , · · · , yn )) |J|, 0,
ó û üý þ (ζ , · · · , ζ ) ¹ å_O£¼ ¹Ãÿ À @A t p ûüý þ (ζ , · · · , ζ ) ¹ ÿÓ > D
À±°³²6 ø ´8µ K ÿ HI BC p(x , · · · , x ).
ζ = f (ξ , · · · , ξ ), j = 1, · · · , n, ¹ (ζ , · · · , ζ ) P O£¼ (y , · · · , y ), ¦½
¾ _ P-
°¿ ¯ ò
_-À¼åG ¶·
j
yj = fj (x1 , · · · , xn ),
º
fj (x1 , · · · , xn )
n
xi = hi (y1 , · · · , ym ),
j
ì\í^î\ï
1
n
1
n
F (z1 , · · · , zn ) = P (ζ1 < z1 , · · · , ζn < zn )
|J|
(ζ1 , · · · , ζn )
ó ;<
(y1 , · · · , yn ) ∈ D,
(y1 , · · · , yn ) 6∈ D,
ó ® ¹
(4.4.11)
Jaccobi
ZÄ
n
ÅgÆ¿ÇgÈ¿ÉÊgË
§4.4
= =
Z
Z
153
f1 (x1 ,···,xn )
···
···
Z
fn (x1 ,···,xn )
p(x1 , · · · , xn )dx1 · · · dxn
p (h1 (y1 , · · · , yn ), · · · , hn (y1 , · · · , yn )) |J|dy1 · · · dyn ,
°Ò¿²gÌÍP¯ κ !þÏ® (4.4.10), ÐGûüý þ (ζ , · · · , ζ ) ¹ ÿ HI BCÑ (4.4.11) ÐÓÔ ` 4.4.4
ÕïðñÖ×ûüØPÙÚrÛÜGûüþ ξ Ý η ÞÓ°ß àáâãàá Ú?OGä> ξ Ý η åæçèÔ Ò Q ξ Ý η éêëìíÛî N (0, 1), sd°ï àá (ρ, θ) ¹ ÛîÔ ð ñò −∞
−∞
1
ó
(0, ∞) × [0, 2π)
t p
(ξ, η)
Ý
(
R2 (
∂x ∂r ∂y ∂r
∂x ∂t ∂y ∂t
p(x, y) =
Ðü¿t
(4.4.11)
¯ º ò Ú
(ρ, θ)
q(r, t) =
V ýþÿÞ ùú û
θ
Ý
ρ
x = r cos t y = r sin t
ôÙõö ) ª÷¹ PP®Ú?® ¹
|J| =
¹ øùúû
cos t −r sin t = sin t r cos t
ZÄ ¯
=r .
¹ øùúû
2 1 r r exp − , 2π 2
r > 0, t ∈ [0, 2π).
åæçèÚ °¿² θ ê ë
[0, 2π)
n 2o q1 (r) = r exp − r2 ,
éý¬ ÷ ¹ Ì! ¼ â Ì" ¼#
Jaccobi
2 1 x + y2 exp − , 2π 2
§4.4.4
° $ ó #
n
(Ω, F, P )
¹
¹ Ûî
(4.4.12) ρ
¹
r > 0.
n
¬
η1 = max{ξ1 , · · · , ξn }, η2 = min{ξ1 , · · · , ξn }.
η1 (ω) = max{ξ1 (ω), · · · , ξn (ω)}, η2 (ω) = min{ξ1 (ω), · · · , ξn (ω)},
ω ∈ Ω,
ω ∈ Ω.
ξ 1 , · · · , ξn ,
ü
154
Ò)¹
η1
Ý
η2
%&(' ÅgÆ¿ÇgÈ
*+ ó Ô-,./Ú-0
(η1 < x) = (max{ξ1 , · · · , ξn } < x) n \ = (ξ1 < x, · · · , ξn < x) = (ξk < x) ∈ F,
(4.4.13)
(η2 < x) = (min{ξ1 , · · · , ξn } < x) =
(4.4.14)
k=1
1
2
η1
k=1
n \
349: ¯
(ξk < x)
k=1
!
=
n Y
P (ξk < x) =
k=1
(η2 ≥ x) = (ξ1 ≥ x, · · · , ξn ≥ x) =
5
n Y
P (ξk ≥ x) = 1 −
1
2
k=1
n Y
k=1
n Y
Fk (x); (4.4.15)
k=1
n T
k=1
(ξk ≥ x)
Fη2 (x) = P (η2 < x) = 1 − P (η2 ≥ x) = 1 − P = 1−
F1 (x), · · · , Fn (x)
η2
Fη1 (x) = P (η1 < x) = P
º
(ξk < x) ∈ F.
¹ Ûî1 1
åæçèÚ-â 1¢121314
η Ý η ¹ )Û î F (x) F (x). ,./Ú 6 (4.4.13), è7º8 ξ1 , · · · , ξn
n [
n \
k=1
(ξk ≥ x)
(1 − Fk (x)).
! (4.4.16)
;(< 0= ¹ ó (η , η ) ¹> øÛîÔ ) ? « çèéÛî@øA ¹ þÿÔ B Ò ÿ ξ , · · · , ξ ó çèéÛî ¹ Ú ¹C éÛîû F (x). 4.4.5 D 5 ¹ Ì! ¼ η ÝÌ"¼ η ¹> øÛîÔ Ò ÿEýÎÚ(FG F (x) ûHIJ ÛîÚ-ð K0 ùú p(x), D 5 (η , η¹) > ¹> øùúÔ â (4.4.14) ¯ Ú-N ñ L # ü G(x, y) ÞÓ (η , η ) ø Û î M Ô 6 (4.4.13) O # x ≤ y Ú-0 T 1
n
1
2
1
1
2
2
n
G(x, y) = P (η1 < x, η2 < y) = P (η1 < x) = P
x>y
Ðü
Ú-0
(ξk < x)
= F n (x);
k=1
G(x, y)= P (η1 < x,η2 < y) P (η1 < x) − P (η1 < x, η2 ≥ y) = n n T T n =P (ξk < x) − P (y ≤ ξk < x) = F n (x) − (F (x) − F (y)) .
¹> øÛîû ( k=1
(η1 , η2 )
G(x, y) =
k=1
F n (x) − {F (x) − F (y)}n , x > y, F n (x),
x ≤ y.
(4.4.17)
ÅgÆ¿ÇgÈ¿ÉÊgË û HIJÛ¯ îÚPò K0ùú > øùúF (x) MÚ 6 (4.4.17) Ú 0
§4.4
q(x, y) =
155 p(x)
ÚPü
q(x, y)
∂2 n−2 G(x, y) = n(n − 1) {F (x) − F (y)} p(x)p(y), ∂x∂y
ÞÓ
(η1 , η2 )
¹
x > y. (4.4.18)
QRSTUQRVWXY µ1Z Ö ó !1 ¹ 1 1 11 ª÷¹ 1 ¹µ1Z Ö [ 1 Ð 1 \ ] ^ Ô 1 _ 1 ` 1 a b Ô?ûcdefÚ-g h ¬ ª÷¹ µZ Ö Ô G ξ , ξ â ν ó ¹ ` éý¬ ÷ â (Ω, F, P ) / ¹ 3 ¬åæçè ¹ ¹ Ú?°¿² ξ Ý ξ Ûî ÛÜû F (x) F (x), ν ûiû p, 0 < p < 1 Bernoulli Ô-j ζ = ν ξ + (1 − ν) ξ , (4.4.19) )k ¹ ζ ülû ξ Ý ξ ¹ µZ Ö Ô?°$ ó §4.4.5
1
2
1
2
1
2
1
1
2
2
b5 ζ ¹ Û îÔM6
â ν gm 1
h 0 ¬¼Ú?Ðü
ζ(ω) = ν(ω) ξ1 (ω) + (1 − ν(ω)) ξ2 (ω) ,
ω ∈ Ω.
Fζ (x) = P (ζ < x) = P (ζ < x, ν = 1) + P (ζ < x, ν = 0) = P (ν ξ1 + (1 − ν) ξ2 < x, ν = 1) + P (ν ξ1 + (1 − ν) ξ2 < x, ν = 0) = P (ν ξ1 + (1 − ν) ξ2 < x|ν = 1)P (ν = 1) + P (ν ξ1 + (1 − ν) ξ2 < x|ν = 0)P (ν = 0) = P (ξ1 < x|ν = 1)P (ν = 1) + P (ξ2 < x|ν = 0)P (ν = 0) = P (ξ1 < x)P (ν = 1) + P (ξ2 < x)P (ν = 0) = p F1 (x) + (1 − p) F2 (x) .
Ò (4.4.19) ¹ ¹ µZ â ¹ Ûî n ó Ûî 1 ¯ Þ gÚ ? § ¹µZ â Ô oü p EýÎ ¹qr Ô G ξ , ξ â ν ó ¹ `éý¬ ÷ â (Ω, F, P ) / ¹ 3 ¬åæçè ¹ ¹ Ú?°¿² ξ Ý ξ Ûî ÛÜû F (x) F (x), ν ûiû p, 0 < p < 1 Bernoulli -Ô j (4.4.20)
1
2
1
2
1
η1 = max{ξ1 , ξ2 },
ü5º )k¹ ζ ¹ Û î
2
η2 = min{ξ1 , ξ2 },
ζ = ν η1 + (1 − ν) η2 . Fζ (x):
Fζ (x) = p Fη1 (x) + (1 − p) Fη2 (x)
= p F1 (x)F2 (x) + (1 − p) {1 − (1 − F1 (x))(1 − F2 (x))}
(4.4.20)
%&(' ÅgÆ¿ÇgÈ
156
= p F1 (x)F2 (x) + (1 − p) {F1 (x) + F2 (x) − F1 (x)F2 (x)}
¯ ² ¹ F (x) ws* ó 3 ¬8Û8îs s F (x), F (x) â F (x)F (x) s s s t s u 8 8 v Ú / ¹µZ â Ú-x óy < p < 1 k Ú-z0 F (x)F (x) ¹µZ : 2p − 1 < 0 , Ðü ) k F (x) { ó 3 ¬Ûî ¹ “ |(}ø ”. x ó ü~ )k F (x) Ûî
¹ 3 ¶ Ô /s hss
s ws*scsd8Úxszs¹ ssE8¹ ýÎs¹ 8Ûîs¹ ¹ s^Ú+ ý8 çè Ûî Ô §4.4.6 T 11 ÷ (Ω, F, P ) / ¹ n 111 Ú-1* Ú ó 1 G ξ ,···,ξ ` é ý ω ∈ Ω, ξ (ω), · · · , ξ (ω), ¾ ó n .Ú ) ü ;(< ¹ !"Ú {1«¬?1 ®ü ¯11 1Ò ¡£¢ ¹ Ì1! ¼ hâ Ì1" ¼Ú-1¤1 ü1¥ á 1¦ ¹ ë1"181! ¹1§1¨ªÒ © Ä°Ô ÿ±¢(0² å³ÚL´µ ü« ¶ " Ä`s·¾×ÒÚL)7 ¸ ÿ (¡ »1¼ Ä/1` ½1ξ1(ω)¾1¿ ¡· ξ (ω). ).ó ` ξ n ó ω ý / 11 ` Ω §1ξ (ω)¨ ¡=Íξ Ú-(ω),11 ¹ i <¸ j,`1º´¥ k 1ξ (ω) /½.À Ú k = 1, 2, · · · , n. Á¤*0 = (1 − p) F1 (x) + (1 − p) F2 (x) + (2p − 1) F1 (x)F2 (x) . ζ
1
1 2
1
2
2
2
ζ
ζ
1
n
1
i
1
n
j
i
j
∗ k
∗ k
ξ1∗ ≤ ξ2∗ ≤ · · · ≤ ξn∗ .
(4.4.21)
/½$ ó # ξ (ω) ≤ ξ (ω) ≤ · · · ≤ ξ (ω) , ∀ω ∈ Ω. Ã Ò Ã ) à ÃÃ¥¸ §¨Ä ½ {ξ , ξ , · · · , ξ } lû {ξ , · · · ,âξ Í} ½ §Ã¨ÃÄ Ä ÃÚÅ+Ãlû {ξ , · · · , ξ } ½Æ Ô `ǽÈÉÊ4ËÌ i ¢(0Æau Ô Î ÜÏ ξ = max{ξ , · · · , ξ }, ξ = min{ξ , · · · , ξ }. ` ξ , · · · , ξ åæçè k Ú-Ð( ξ â ξ EÑÒÓÇÔ F1G1111 ξ , · · · , ξ çèéÛî (i.i.d.), êë C é1½ Ûî1 1 F (x), _1` bÓÇ ξ ½ ÛîÚ-±¢ 1 < k < n . tu8 ¬Ô 0 k " x. (ξ < x) ⇐⇒ ` ξ , · · · , ξ ¢ ü A ÞÓ,Õ (` ξ , · · · , ξ ¢ Ñ 0 m " x), ó ,Õ A , · · · , A hh {Ö Ú-Á¤0 ∗ 1
∗ 1
∗ 2
∗ 2
∗ n
∗ n
1
∗ n
1
1
n
∗ 1
n
∗ n
n
1
1
1
n
∗ 1
n
∗ k
∗ k
m
1
1
(ξk∗ < x) =
n
n
n [
m=k
Am ,
1
P (ξk∗ < x) =
n X
m=k
P (Am ).
n
(4.4.22)
n
(× ØÙ(Ú¿ÉÊgË N ñ Û P (A ) = C ën0 §4.4
− F (x))n−m ,
m = 1, 2, · · · , n .
Cnm F m (x)(1 − F (x))n−m ,
m = 1, 2, · · · , n .
m
P (ξk∗
< x) =
Î ÜÏÚ-0 tu8
n X
m=k
157
m m n F (x)(1
(4.4.23)
∗ P (ξn−1 < x) = nF n−1 (x)(1 − F (x)) + F n (x) = F n−1 (x)(n − (n − 1)F (x)). n P Cnm F m (x)(1 − F (x))n−m = 1,
oüÛ
m=0
P (ξ2∗ < x) =
n P
m=2
Cnm F m (x)(1 − F (x))n−m
= 1 − (1 − F (x))n − n F (x)(1 − F (x))n−1 = 1 − (1 − F (x))n−1 (1 + (n − 1)F (x)).
±ÜÝÞß(àáâ¿ûãäÔ 1. 2. 3. 4. 5. 6. 7. 8.
åæ 4.4 óêôêïêõêîêöê÷êøêùPúüûPý îêïêõêþêÿ ç èêéêëêìêíêîêïêðêñPò êöê÷êøêù éêëêìêíêú þêÿPóêè û
ìêí þêÿ ç éêëêìêíêú óêñêò ûêý î
ç éêëêìêíêú óêñêò ûêý î þêÿ ñêò êîêóêôêïêõêú ûêý î þêÿ êöê÷êøêù ñêòêïêõPú ûP ý î þêÿ è ö ÷ ù ú é ë ì í ó ñ ò ï õ ú û ý p î þêÿ êîêóêôêïêõêúüûêý Pöê÷PøPùPî êþêöêÿ÷êøêù éêëêìêíêúêñêò !" #%$&'ê î ()*êù + ,ê.ú -/êî 01 2 éêëêìêíêîêöê÷êøPùP.ú PñPò î ïPõP.ú 3456 ûPý îêïêõêþêÿ 7 56 éêëêìêí êñêòêé 8êîPïPRõ û 9,:;<êù îêïêõêþêÿêè ξ, η
[0, 1]
p(x) = e−x , x > 0,
ξ, η
ξ 1 , ξ2 ξ, η
N (0, 1),
(ξ, η)
ξ
ξ2
(1) eξ ; (2) 1/ξ 2
ξ 1 , ξ2 , ξ3
η =
ξ2
(3) ζ2 = min(ξ1 , ξ2 ).
ξ 1 , · · · , ξ5
Rayleigh
Fi (x) =
ξ12 + ξ22 + ξ32
(0, 1)
(2) ζ1 = max(ξ1 , ξ2 );
η = max{ξ1 , ξ2 , · · · , ξ5 } ξ 1 , · · · , ξn
ξ ξ+η
ξ η
5
σ2 = 4
10.
ζ=
D = {(x, y) : 0 < |x| < y < 1}
(ξ1 , ξ2 , ξ3 )
ξ1
ξ+η
η 1 = ξ 1 + ξ 2 , η2 = ξ 1 − ξ 2
N (0, 1),
(1) η = ξ1 + ξ2 ;
9.
ζ = ξ+η
p(x) =
(2)
F (x) i−1
0
, x > 0,
P (M > 4).
ξi∗
F (x),
n! (i−1)!(n−i)!
2
x − x8 e 4
t
(1 − t)n−i dt,
i = 1, · · · , n.
(1)
=?>?@
A?B?C?D?E?C?DGFGA
ó Ð( òIHIJLKIM â â ON(IP0IQî SJ RLÁ¤8UT ·ûIV J Q îs] ss+J sSWSXsss sON ½Sâ YÄ ýSZKSRv_s` sabS[I\8ý± ZK Á34 bI[I\ÉI^ì?íIQî ¢(½I_!ÆaIQîIR `babcbdbebfbgb` óIsp sss½sSh ÎSi k ó ý Sj l J óSIkSq l ssssss½8ýSmsÆsaSnSo J IWIX ½ýImÆa½ R §5.1
+
rIsItIuUIvIwIxIy s SzS{ ó ssss½8ý S|S}I~ ½Sh ÎSiSJ sS¯ b J OIOs p ½SSu R ÿüJ ξ I ýI
¢ 110 II8½II I 19 J ¯ ξ ½IQII ¡I *9I JI ξ ½I À 7ýI
¢(½I I J ÿI p II9I ξ ½IQII¡I *+9I ξ ξ IJ ýIII½Æ ½I À 7ýIJ II ½I I Æ-³ ³IR c d I ¥ý ξ ½I ÀnO ½IzI{ILR ,./ J 6 Ï SS ssSs ½S S¡ J ýSSSs ½sÆs ξ PSs¢ 2Ss£ 8S¤ ½sÆs J xSs¥ s¦t ÀS§S¤ ½sÆsS¨S©SR«ªsSSsnS¥¬rSsStSuª S® ls½sbS¯SR«° 6 us ξ ½S )SJ ss¥ssss ξ ½S Às¾s¿ Eξ, ± ¢±hS² E ¥S³Ss ´ dSµ Expectation(z { ) ½ºI¶ hI²IR M 511111½1 y *1» {¼ ½Q½¾¿QR 1 b O1h · À º ¸ ¹
B R IÀ ξ ¥III¶I 5.1.1
¢ 110 II 8½II ¯ ¾ ½11 J D 5 ξ ½II· ÀIR s Ð Ss Ò üJ )sk SSÁI ξ ÃSÄ Poisson QS P (λ), ± ¢ λ > 0. sª nS¥S P (ξ = n) = e , n = 0, 1, 2, · · · . ªÆÅ ξ m {Ç1À1Z ½111J ¥1{Ç1½ J ) ±·1À Eξ Ê y ¦È ξ m1{Ç À½{IÇ ½¿IÉ I· I §5.1.1
−λ λn n!
Eξ =
¥
7IÊIÃIB Ä p:
∞ P
nP (ξ = n) = e−λ
∞ P
nλn n!
= e−λ
∞ P
λn (n−1)!
= λe−λ
∞ P
λn n!
=λ.
QI P (λ) ½IËIÌIÍ ξ, 0 Eξ = λ . I I À ÎIÏ HIÏ¿IÐIÑÆIÒ½ Beinoulli ÓIÔ J ¶ ¯IÕIÖ ½I×IØIP 5.1.2 ¯IÕIÖ IÚIÛ½IÓIÔ ¯ ¾ J IÓ Ü ξ ½II·ÀIR 0 < p < 1, ξ I³IÙºI¶ n=0
Poisson
n=0
n=1
158
n=0
§5.1
Ý ÞßIàIáIâIãIÝ O ÎIÏ Ð(Iä H ξ ÃIÄIå M QI
159 G(p),
P (ξ = n) = (1 − p)
IèÊIéIç ÂIIÜ°±À J ÎIÏ
¾
Eξ =
∞ P
nP (ξ = n) = p
∞ P
nxn−1 ,
éIêI¾IëIìIí [0, x ] ¢¶IîIïIð J ±Oñ 1
ó è
0
q(u)du =
Eξ = p
∞ R P x
n=1
∞ X
0
nq n−1 = p
n=1
∞ P
n ∈ N.
nq n−1 .
n=1
n=1
G(x) :=
p := q n−1 p,
n=1
g(x) =
Rx
æIç
n−1
0 < x ≤ q < 1.
ÁIòIç
q < x1 < 1, ∞ P nu du = xn = n−1
n=1
x 1−x ,
0 < x < x1 .
d p 1 G(x) |x=q = = . 2 dx (1 − q) p
(5.1.1)
éôõ1ÒöÆÅ J ç÷øê¾ùäúëôõû¾üzû{ù1ÒûöÆñý¢ûçþR ÿ J OÅ IÀ ¶ IÓIÔ ÕIÖ ùI×IØI p, IIÎIÏ ÙI¶ ÕIÖ (5.1.1) ¢I ç IÚIÛIùII·IÓI Ô I ¾ I¥ . J IÀ ¶Ië ¶ OñOñ 10 ùI×IØI¥ , ] ÛOñ¶ 10 J I I·IIÚIÛ 5 IR ª q “¾IüIzI{ ” ù IR !" #$ J ÎIÏ %&IJ Ê '()*+ùI» ,-IËÌ .IÍ ξ, /I¾Iü ÎIÏ4567 ÎIÏ zI{I¥I ¶ 01I I ê I ¾ ù 2 L 3 I ª I I ê I ¾ S ù I ï ð 8 9 ä :3LêI¾ ùI ?ïI@ðA8IB ç/I$Ü 23C¶ D3E/¥2;IFÊI.ïIGEðHI3Ê ¶ '<¥=I<ïI=IðIïIùIðêI9ʾ '3EI ;I!ÊI" ïIAðIB ùIÜ êI2J¾C3>0D3 )IVW K & FIÇIù 2+ó 9L¾Iü ÎILÏ MI4¥I5 ËIÌ .IÍI ù NçI ¾ OPQJ3ERI ¶ SJTI ù ÎI+ 3EZU Ï Ü2CD0I÷3 è3 ÛIÜXUIùIêI¾;IÊIïIð9çY'Iè3 1 p
1 5
[\] T ^_ 5.1.1 \ À »,-IËIÌ.IÍ
ξ
`Içabc
P (ξ = an ) = pn ,
I V d 3 IÎ Ïe êf
∞ X
n=1
n ∈ N,
|an |pn < ∞ ∞ P
ù2gh ξ ùfIüLM3ij Eξ. \k P
an pn
n=1
∞
Ig
ξ
ùfIüLMFlIë9
n=1
|an |pn = ∞,
(5.1.2)
(5.1.3)
m no ÝpqrIáqrsÝ t è % 3Euv.wIùfIüLMIùlIë8RIç<=Iù9 Vx 3Ey'zJ(Iç{ +Iù|,-uv.w3 } ùfIüLM~TlIë9O / ñP+K [ ùR 5.1.3 (Bernoulli JJJ
JJJJJ ) A RJJS ×SØJSí (Ω, F, P ) ñ ù~uv=3 ξ = I , I I ç Eξ = P (A). } % ~fIüLMFlIëIù|,-uv.wIù 5.1.4 (Peter Paul ) ~~I ù3 & [ h¡9 \k 袣 [¤ n ¥ 3¦I§ Z £ 2 ¨©ª 9¦« ξ ¬£®K & ù ©ª f°¯E3±IÜ ξ ùfIüLM9 ² ´³µ % [ 3 ξ ùabch p(ξ = 2 ) = , n ∈ N, t ' 160
A
n
n−1
∞ P
an pn =
∞ P
1 2n
2n−1 2n
=
∞ P
1 2
= ∞,
®« ξ ù fIüLMFlIë9 ¶ O ñ®· 7 ù Peter 2 Paul abR¸¹Oñù~º»Iùab3R¼½a bOñù~I¾ 翧I8 ù9 y'-uv.Iw ùIf üLM3 } XU ç ^_ 5.1.2 \k -uv.w ξ `IçÀÁÂf p(x), I V n=1
n=1
R∞
d 3 }eà a
−∞
|x|p(x)dx < ∞
R∞
\k ù+gh ξ ùfIüLM3ij Eξ. R
−∞
∞ −∞
n=1
xp(x)dx
|x|p(x)dx = ∞,
Ig ξ ù fIüLMFlIë9 t #JÄJTJJ)J« % [ 3ÅuJvJ.wSùfSüLJMz W /JabSçI÷J3ÅabJXÆIùJuv .JÍ wJS` çJXJSÆ ùJSf üJLJMJ3Å®« }JÇÈ If üLJMgJhaJbIùJfIüJLMJ3ÊÉJËÌ aIb ùuv.Iw ùIf üLM9 } IôIõÎ-abIùfIüLM9 5.1.5 (ÏJÐJJJJJJJ ) JuJvJ.Jw ξ ËJÌJJJaJb U (a, b), ±JÑ Eξ. ² t 'ab U (a, b) ùÀÁÂfÒÓÔ{ÕÖ#× 0, ®« Eξ ~Tl Ó3IØ òÔ R R Eξ =
∞ −∞
xp(x)dx =
b x dx a b−a
=
®«ab U (a, b) ùfIüLMRÕÖIùOñÙÚ+9 5.1.6 (ÛÜ ) uv.w ξ ËÌ
a+b 2 ,
N (a, σ 2 ),
Ñ
Eξ.
§5.1
®«
ÝÞßàáâãÝ ² t '¥äab R∞
−∞
161 N (a, σ 2 )
ùÀÁÂfh
1 (x − a)2 , p(x) = √ exp − σ2 2πσ
x ∈ R,
ØIòÔ
|x|p(x)dx < ∞,
Z ∞ 1 (x − a)2 Eξ = xp(x)dx = √ dx x exp − σ2 2πσ −∞ −∞ Z ∞ Z ∞ 1 (x − a)2 (x − a)2 1 √ =√ (x − a) exp − dx + a exp − dx σ2 σ2 2πσ −∞ 2πσ −∞ := I1 + aI2 . Z
∞
ÚJç ®J\«Jk)J« e J/ ¬JJhJ$J à aÚJ23ÅR t 'åJ$J01 à aæJ;ySïIðJ9ÊØSòµ 3 t = x − a, IÔ n o R I = t exp − dt = 0, à ó åR hè ÂfRéÂfGê~ë 3µì √1 2πσ
1
∞ −∞
t2 σ2
n o R∞ (x−a)2 dx = −∞ p(x)dx = 1 . exp − 2 σ −∞
R∞
íî #Ä3ïK Eξ = a, ð R N (a, σ ) ñùò~óf9 5.1.7 (ô ) uv.w ξ ËÌfab ² t 'fab exp{λ} ùÀÁÂfh I2 =
®«
R∞
−∞
√1 2πσ
p(x) = λe−λx ,
ØIòÔ
ç ú 3 ç t = λx. öIþ Γ Â f R ∞ 0
exp{λ},
Ñ
Eξ.
x > 0,
|x|p(x)dx < ∞, R∞ R∞ Eξ = −∞ xp(x)dx = λ 0 xe−λx dx =
/ ñ } j ¤ .wõ B ®«
2
1 λ
R∞ 0
te−t dt = Γ(2) = 1,
te−t dt,
ð R exp{λ} ñóf λ ù÷f9 ! " #Äø3 }%& (1) øabùfüLMæ W } ùùófÔ ÷J3Å/úñûJJaJbJ2JJfJabSù®JÔóJfæ [ü Ó J} ùJfIüLJMÚúñ3Å¥äJab} IezþÔÿò~óf a [ü 3IØ ò R¥äab N (a, σ ) ùfIüL"M 3«ý & (0/1 ò)à aó2f σf ®ø¬Iù2G8(2)3Ó fI& üøLMIfù ç ñ23` I3þ \ Γ Âf3 9 W |,-3 Ç ÔLMFlÓ -ab9 % ~ 5.1.8 (Cauchy ) p(x) = , x ∈ R, I (1)p(x) R~ÀÁÂf (XU abgh Cauchy ab ); (2) Í ab LMF lÓ9 Eξ = λ1 ,
2
2
1 π(1+x2 )
162
®« ®«
² ´³µ % [ 3 R p(x)
∞ −∞
mno ÝpqráqrsÝ p(x)
×3RØ
p(x)dx =
R~ÀÁÂRf (g h ∞ −∞
1 π
∞ 1 −∞ 1+x2 dx
Cauchy
|x|p(x)dx =
=
1 π
arctan x ∞ −∞ = 1,
aR b ), R
2 π
∞ x dx 0 1+x2
= ∞,
ab LMFlÓ9 §5.1.2 !"#$% fLMFÒRuv.w (&abÂf ) ~ fOPQ3HR'(/£f OPQ )*3®« ÌFÆ+Áy/,-. 9 y'-uv.w3 V /fLMlÓ d 3 } Ô Cauchy
Eξ =
Z
∞
xdF (x),
(5.1.4)
åR t ' (Xy' Lebesque /Á ) Î0 Ô F (x) = p(x). \k } ö Riemman-Stieltjes à a ¸13 Ç )« È |,-uv.w f LM¬h (5.1.4) 2 29 } Ì3.Âf4ñ ç :3 \k f (x) 2 g(x) RTÓ R # 3+Âf9y ' a < b, ÕÖ [a, b] a5 < x = b, 6 ( t ∈ [x , x ], j = 1,π 2,: · ·a· ,=n,x)<«xT/< · · ·Riemman-Stieltjes 2h −∞
d dx
0
j
j−1
1
n
j
Sπ =
n X
g(tj ) {f (xj ) − f (xj−1 )} .
(5.1.5)
\k F407a53 \ 7(Ù3 V || π || := max (x − x ) → 0 d 3 Í Riemman2Í lÓ8~9T :{ I ∈ R, Ig g(x) ;' f (x) ÓÕÖ [a, b] # R-S ) ÃStieltjes J È Ã 3aØ<3 ih :J{ I gJh g(x) ;J' f (x) JÓJÕJÖ [a, b] #< R-S(Riemman-Stieltjes) j=1
1≤j≤n
=
I=
Z
j
j−1
b
g(x)df (x).
(5.1.6)
³µ È R-S(Riemman-Stieltjes) Ã a ¸1=> & (−∞, ∞) #9 \k e `Ôabc (5.1.2) |,-uv.w ξ abÂfij F (x), I F (x) Rç~?@AB ×CÔDÂf9 V <= (5.1.3) EF d 3 t R-S Ã a T)« Z
∞ −∞
xdF (x) =
∞ X
n=1
a
an (F (an + 0) − F (an )) =
∞ X
n=1
an pn .
(5.1.7)
Ý ÞßàáâãÝ ®G «|,-uv.w ξ fLM V Ç ) «V ¬h 3uv.w ξ fLMlÓ3 Z Ò §5.1
∞
E|ξ| :=
163
(5.1.4)
2 29Ø Í 2¬
|x|dF (x) < ∞,
(5.1.8)
Ó3H} #;' F (x)R-S ) à 9 ü Ó IJK (5.1.7) 29LÉ & Í 2 R P P Eξ = a P (ξ = a ) = a P {ω | ξ(ω) = a }. /Q ñ {{ωà | ξ(ω) = a %}, n ∈ N } R~*=3G M } ð NEy Ω ~aO3P 3Ì a4 RÙ 3 (5.1.7) 2Zð ¬ 3y'|,-uv.w ξ, Ô −∞
ï
|x|
∞
n
∞
n
n=1
n
n
n=1
n
Eξ =
ξdP.
(5.1.9)
Ω
å} RSS3 |G ,3-yu'v.w -uξ vf.wL3 MÇ ÔRÆ @ ξ Ó TΩ 4#9 ;'¸¹/Á y'uv.w ξ, i
P
à a9
æR×uv.w3agh ξ ¥U2U9³µ % [ ξ = ξ − ξ , |ξ| = ξ + ξ . î ®«T fLM T) ç Eξ lÓ3 V ' Eξ < ∞, Eξ < ∞. } G 'JR z<JaJ<W Eξ 2 Eξ `JÔJ¬<X<2 (5.1.9). YJ)JFZJ ξ JRJ×<u v.w9 y'×uv.w ξ, Pi P ≤ξ< , n ∈ N. ξ = Í 2¬ G V d ≤ ξ(ω) < 3Ô ξ (ω) = , P Q Ô µì
ξ+
2
ξ − = max{−ξ, 0},
ξ + = max{ξ, 0},
ξ−
−
+
+
−
+
−
+
n
∞
m−1 2n
m=1
m−1 2n
−
m−1 2n
m 2n
m 2n
m−1 2n
n
ξ (ω) ↑ ξ(ω), n → ∞, ∀ ω ∈ Ω. Q d V P 3 Eξ lÓ 3Ô Eξ lÓ3Ø ↑ Eξ, n → ∞. t ' ξ h|,-uv.w3`Eξ Ô¬X2 (5.1.9), ®« n
n
n
n
R
R
= Eξ. @å }[ WK ¤ y×|,-uv.w3 Ç Ô ξdP (5.1.9) 2EF9 } ç ö3.Âf Ô; 3 )«WK ^\ 5.1.1 (]^ ^\ ) \k ξ RTÓ¸¹Ö (Ω, F, P ) # uv. w3 F (x) h/abÂf3Z Iy 6 7 BorelZ)/Âf g(x) æÔ Eξn =
Ω
ξn dP ↑
Ω
g(x)dF (x) =
R
g(ξ)dP.
Ω
(5.1.10)
m no Ý pqráqrsÝ Í_ 2 ÉR \k ~`lÓ3Iê~` Ç lÓ3ØX _ 9 §5.1.3 ab \k ycdf c, eKyuv.w ξ, Ô P (ξ = c) = 1, }f Suv.w ξ h}Ègh (' c) uv.wf 3 Qd Ô ξ = c, a.s. ( almost sure, ïÎ0 4 x ). ! d gh' c uv.w ij c. ö¬X2 (5.1.9), Fï)«= [ uv.wfLM \] ~i*8 ^\ 5.1.2 j c hdf3Øj®· 7 uv.w fLMælÓ3 } Ô 164
1◦ . Ec = c; 2◦ . E(cξ) = cEξ; 3◦ . E(ξ + η) = Eξ + Eη; 4◦ .
k
ξ ≥ 0,
I
Eξ ≥ 0;
k ξ ≥ η, I Eξ ≥ Eη. HöT 5.1.1, } )«K & ^\ 5.1.3 \Jk uJvJ.Jw ξ `JÔJaJbJÂJf ◦
5 .
æÔ
Eg(ξ) =
Z
∞
F (x),
IJy 6 7
Borel
)
g(x)dF (x).
g(x)
(5.1.11)
Í_ 2 ÉlR \k ~`lÓ3Iê~` Ç lÓ3ØX _ 9 } ç : 3y' Borel )/Âf g(x), η := g(ξ) Ç Ruv.w9 ¶m 3onpf LM Eη Tl3 } U Vqr Ñ [ η R abÂf G(x), snpt2 Eg(ξ) = Eη = xdG(x)
u Ñ η fLM9T 5.1.3
v uR|}w~« xö ξ Ã abÂf F (x) y[z m (5.1.11) 2 η î fLM3{ î 9ö R-S a3F (5.1.11) 2Ó-
2|,-
`29 VU [ 3 (5.1.11) 2JÓ }< < ] Ç R<E
∞ −∞
1
1
Eg(ξ1 , · · · , ξn ) =
n
n
∞
···
∞
g(x1 , · · · , xn )dF (x1 , · · · , xn ).
(5.1.12)
yXF uv.w à 3 } Ô ^\ 5.1.4 \k ξ 2 η RTlÓÆ~c¸¹Ö XF uvw3 M } fLMælÓ3IM } à ξη fLM Ç lÓ3ØÔ −∞
−∞
Eξη = Eξ · Eη.
Ý ÞßàáâãÝ } Òy Z [ W G 9j ξ 2 η a`ÔÀÁÂf } î ÀÁÂfh p(x, y) = p (x)p (y). t (5.1.12) 2w ç p (y), RM §5.1
2
1
165 p1 (x)
2
2
Z ∞Z ∞ Z ∞Z ∞ Eξη = xydF (x, y) = xyp(x, y)dxdy −∞ −∞ −∞ −∞ Z ∞Z ∞ Z ∞ Z ∞ = xyp1 (x)p2 (y)dxdy = xp1 (x)dx yp2 (y)dy = EξEη. −∞
−∞
−∞
−∞
| W G Z 9 }m ab fLM9 5.1.9 ( ) uvw ξ ËÌab B(n; p), ± ² } ë Eξ. "´i q = 1 − p. npfLM Tl } Ô Eξ =
n X
kP (ξ = k) =
k=0 n X
= np
k=1
n X
kCnk pk q n−k =
k=0
n X
Eξ.
k · n! pk q n−k k!(n − k)!
k=1 n−1 X
(n − 1)! (n − 1)! pk−1 q n−k = np pm q n−1−m = np. (k − 1)!(n − k)! m!(n − 1 − m)! m=0
¡ ξ h n ¼F¼¢ Bernoulli ±£ño E¤¥f¦ y§¥±£T l~cuvwï \k ò k ¥±£E¤ f ξ = 1; ¨} I f ξ = 0. R ξ , · · · , ξ RXF ófh p Bernoulli uvw Ô P ξ= ξ ; Eξ = p, k = 1, · · · , n. P Q© YfLM ª ç k
1
n
k
n
k
k
k=1
Eξ = E
n P
ξk =
n P
Eξk = np.
5.1.10 «úñûÔ<¬< 1 ® n n ¯<°<±< ü Ìúñ³²<´µ³¶ 6<· [ m ¯ (m ≤ n). ±Ñ m ¯°±¬Ú¸ f¹º¦ ² Ê« ξ ¬J m ¯<°<±<< <¬<JÚ<¸<¦¼»JR ξ JaJb<²JµJÑ<½<¦ } LJÉ<¾< ~· ¿Ô C _ ÁÀàî {1, 2, · · · , n} ñoÄ ·ÅÆ fÇ {a , · · · , a } fÇ ë2¦Q ø ¸X ¦hÑ ξ ¹ºzPy®ÔåùfÇño fjÈïwP Eξ = (a + · · · + a ), }É Lɾ2Ê` ¸2ño§c k ∈ {1, 2, · · · , n} æ [ü¤ C ¥® «½¾ P k=1
k=1
m n
1
1 m Cn
Eξ =
1
m
m
1≤a1 <···
m−1 Cn−1 m Cn
n
k=
m−1 2 Cn−1 Cn+1 m Cn
¶Ë ̤ ~ͽLÉ ë¦ k=1
m−1 n−1
=
m(n+1) . 2
mno ÝpqráqrsÝ
166
ÎÏ p Ï }ÑÐoÒ çÓ uvw ξ f¹º Eξ f RM ÈÍÔP Q Ì~TÉl Sf¹ºm ÕÖ ¤ uvw® · ÚÍ “ ño×Øf Ù ”. »R }Ç w« fOPQ ÕÖuvw “ ño×ØÙ ”. ñoØf RåÚ~fOPQ¦y <²lJÓJf<<¹<º< JuJv<Ç Jw<ÅåV Õ<ÖJ`Û<½ÜJh¼< ÅïeJyJlÓJf¹ º uvw ñoØf R~X Ô fÝÞߦ ^_ 5.1.3 g µ àuvw ξ ñoØfá k §5.1.4
P (ξ ≤ µ) ≥
1 , 2
P (ξ ≥ µ) ≥
1 . 2
(5.1.13)
à uvw ξ ñoØf d } w«ij µ(ξ) = µ. t JÄ<ã
ëì ñoØï¦Í½LÉ àÄãlñ®å ² æàð ¦ }m ä~ù Ëñ ¦ 5.1.11 ±Ñ¥äëì N (a, σ ) ñoØï¦ ² ´uvw ξ ∼ N (a, σ ). t ¥äëì N (a, σ ) àë쮫 â
µ
1 2
2
2
2
P (ξ ≤ a) = P (ξ < a) = Φ
ξ−a σ
= Φ(0) = 12 ;
QP ¥äëì N (a, σP)(ξ ≥ñoa)Ø=ï1ò −a.P (ξ < a) = 1 − Φ(0) = . 5.1.12 JuJv<Jw ξ · Í< î ò {−1, 0, 1}, Ø< ξ · êúñ³§
2
1 3
P (ξ ≤ 0) = P (ξ = −1) + P (ξ = 0) =
2 3
> 12 ;
P (ξ ≥ 0) = P (ξ = 1) + P (ξ = 0) = > . © ó ® « ãl 5.1.4, ξ ñoØïà 0. 5.1.13 uvw ξ · Í î ò {0, 1}, Ø ξ · êño§cÍ ¸¹æ à , ±Ñ ξ ñoØï¦ ² } çÓ ξ f àóïò Bernoulli uvwôM ëìÂïà~c õ ö Âïê2ò 2 3
1 2
1 2
x ≤ 0, 0, 1 F (x) = 2 , 0 < x ≤ 1, 1, x > 1.
1 2
Ý ÞßàáâãÝ 167 ²äåy 6 7 0 < a < 1, } æÔ P (ξ ≤ a) = P (ξ = 0) = ; P (ξ ≥ a) = P (ξ = 1) = . © ó Ì÷ ãl 5.1.4, ÕÖ (0, 1) ño 6 7~c3ïæà ξ ñoØï¦ yG â z«Îc Ëñ } ä¾ 1 uvÍ w ñoØï6 ²~ã8~ Øw« W ñoØï²8~ø ~ãùÓúcÇ ÕÖ f ÕÖño 73ïæàñoØï¦ Ô 2 ïeûüý ξ Ô8ú ñoØï µ, ²úã §5.1
1 2
1 2
◦
◦
P (ξ ≤ µ) = 21 ,
P (ξ ≥ µ) = 12 .
þÿ w¶ãl p ëØï 5.1.4 0 < p < 1, µ àûüý â
p
à ûüý ëØï¦ µp
P (ξ ≤ µ) ≥ p,
ξ
ξ
p
ëØïá
P (ξ ≥ µ) ≥ 1 − p.
ñoØïø þÿ w
(5.1.14)
µp (ξ) = µp .
ñoØï f à
5.1 1. ! 4 "#$%&')(*+,-" ./!01234 , 5670"8089:;4<=+> 2. ?@A n BCDEF0GHIJKL BMNJO) PQRSBTJUVNJK WX OZY[\]^Z-_T` (1) abcd (2) bceDOZfTJ_8 ξ 089:;O 3. (*ghijklmn-o0 10 Y 30 Y 50 Ypjq?rsatpj0ouZ,vowRoxyzjm4{|0}frsyjm~jou089:;O 4. 0UF
}*Y,u [a, b] wZf089:;O W 5. *{|
ξ Laplace YZf Eξ, 8 , (λ > 0). p(x) = e 6. Y00Y8+ Maxwell Y 1 2
1 |x−µ| 1 −λ 2λ
p(x) =
. *
7.
8.
2 2 2 4x√ e−x /α , α3 π
x > 0, x ≤ 0,
0,
4 8ZTfY0M (( Y0
~n E ¡Z¢£ N (a, σ ), T¥¤¦^
α>0 ξ 1 , ξ2
(
σ E max(ξ1 , ξ2 ) = a + √ . π
ξ 1 , ξ2 , · · · , ξ n
W§ 0 ¡{|
Z¢£E¨Y}8 W E
ξ1 + ξ 2 + · · · + ξ k ξ1 + ξ 2 + · · · + ξ n
=
2
f (x),
T©
k . n
* ξ ¢ £ N (a, σ ) YZf η = e 089:;O 10. *{|
ξ, η E ¡Z¨¢£ª«Y G(p) YZTf 9.
m).
2
a2 −2aξ 2σ2
E max{ξ, η}.
1 2
¬ ®°¯²±´³µ¶³µ²·´¯ 11. ¸. r Q¹º b Q»Z¼£.RS n QZf.¹Q8089:;O 12. ¸. n ½¾¿ZY[À Á 1, 2, · · · , n, £. bcà k ½¾¿ZfÄÅÁÂÆ µ 089:;O 13. ,ÇÈ.ZÉAÊb+cËÌþ¿ZfÄÅÁÂÆ089:;O §Î 8012Ϫ«Ð8Ñ=OZTÒÓÐ80ÔÕ a Ög q, ×{ 14. *{|
ξ SRÍ |
W 0:;~n 10, ØÙÚ,ÛÜÝÞ ξ aßn 10 012O 15. ,à a 0áâÇRÍ ¡S n QlZfEãäå0luãæ0:;O W ç èÎ {|
}89:;é,}©ê^ 16. * ξ P Eξ = P {ξ ≥ n}. W ç è {|
R0Y8}T©RR s > 0 17. * F (x) ? x dF (x) = s x (1 − F (x))dx. W F (x), ëR ξ 0:;é,OZ©Rê^ 18. *{|
ξ 0Y8 Eξ = (1 − F (x))dx − F (x)dx. § 19. *{|
ξ LMS ìQ x , x , · · · , x , ©ê^
168
∞
n=1
+∞
+∞
s
0
s−1
0
+∞
0
−∞
0
1
k
Eξn+1 n n→∞ Eξ
W ¡¨Y0
= max xj .
{ |
ZTf E(max ξ − min ξ ). 21. *æí{|
ξ , ξ , · · · , ξ ¡¨YZë PP(ξ = Pi) = p (i = 1, 2, · · ·), ©ê^ E min ξ = p . W 0.2, òÁ-ú 5 ûü 22. Êá+îïp0ðñòÁóô+îïõö÷Øöy÷Ë+cùø01÷2 ý p_þUyöyËcøòÁ WX þpòÁõöòÁÆu67ÿ 16 û0ouO Tf,Ë¡k ý p0ðñòÁ0_8O 23. 0 n Q@ 0 b,k -@RS Ç ξ .0@0Q8ZW f E(ξ). W 24. *¸. 2 Qq . Á k 0 C Q (k = 0, 1, · · · , n). ¼abc£¸.RS m Q (m < 2 ), f Ç ÁÆ089:;O 25. ¼ n Q¸" !# a L $ b L» %"&£ '(Q¸.à (%")Þ *+B , b -'.Q¸Z . %0/£ '.Q¸.à (%1)Þ *+B ,b -'2Q¸. %13 456(UÃW Þ I % ä £ ' n QZ¸Ã (Ø )Þ *+%87, n _à .ÄÃÅ 0 $0 98 S , Tf ES . 20.
*
2
lim
ξ 1 , ξ2 , · · · , ξ n
1
2
1≤j≤k
U [0, 1]
k
n
1
∞
1≤k≤n
n
i
∞
k
k
k
n
i
k
m=1
i=m
k n
n
n
n
§5.2
:<;<=?><:<;<@
B CDEDFDGDH D I ξ JDKDLDMDNDO r > 0, PDQDRDSDTDKDLDMDN ` OaDb ξ UDcDdDeDV J F (x), fDg §5.2.1
r
E|ξ| =
Z
∞ −∞
|x|r dF (x).
|ξ|r
UDVDWDXDYDZ PDQ\[^]D_ (5.2.1)
h iDOjDhDiDkDl D 169 mDnDoDpDq UDrDcDsDtDu OPvQvw E|ξ| x JDKDLDMDN ξ U r y (zD{ ) |DO} x J r yD~D (zD{ ) | ZDu PDQDDKDLDMDN ξ r D rDU O
DJ ξ ∈ L . m r JDD V OD ξ ∈ L u O mDD s Eξ DDZ PDQDw Eξ x JDKDLDM N ξ U r yv| (~vv| ). vvO m KvLvMvN ξ UvVvWvXvYvvvu O ξ 1 v r U O0D VDWDXDY DKDLDMDN ξ U 1 yD| Z0D O0| UDD VDWDXDYDDDU DD Z I a JD V O m KDLDMDN ξ J r D rDu OPDQDDDDDDDa §5.2
r
r
r
r
Z
r
E|ξ − a| =
∞ −∞
r
|x − a|r dF (x)
(5.2.2)
UV Z ab¡ o£¢ UDrcDst OD r J V Ofg E(ξ − a) } Z D¤D¥ OaDbDKDLDMDN ξ J r ≥ 1 D r OfDg Eξ D O¦D§DDD¨ a ©DJ D Eξ, SDTDKDLDMDN ξ U Da E|ξ − Eξ| UDVDDD DZ aDb r JDD V OªfDg DSDT E(ξ − Eξ) . PDQD¨ E|ξ − Eξ| x JDKDLDMDN ξ U r y ¢^« (zD{ ) |DO m ¢^« | Z r JDD VDu O¨ E(ξ − Eξ) x JDKDLDMDN ξ U r y D¬D | UD®D¯ ¢ O°D± [0, ∞) ¡ U\²^eDV D³D´DµD¶ UD·D¸DZ ¹Dº 5.2.1 x °D± [0, ∞) ¡ U D» eDV g(x) D³D´ ²^eDV OaDb r
r
r
r
r
g
x1 + x 2 2
≤
g(x1 ) + g(x2 ) , 2
∀ x1 , x2 ∈ [0, ∞).
PDQD¼D½D¡D¾ DD¿\À^¿\À^Á ´DµD¶DÂDÃ oDÄ I r > 0, aDbDKDLDMDN ¹DÅ 5.2.1 C ÆDÇDÈ r
Ê ¢ O
aDb r≥1u O
Cr = 2r−1 ,
ËDÌ Ä1m
0
2r ,
r ≥ 1; Cr = 1, r
aDb
0 < r < 1.
¡ U\²^eDV OD
g(x) = x [0, ∞) r ξ1 +ξ2 r |ξ1 |+|ξ2 | ≤ 2 ≤ 2
ÎD© XDY OÏDÐ
|ξ1 |r +|ξ2 |r , 2
E|ξ1 + ξ2 |r ≤ 2r−1 (E|ξ1 |r + E|ξ2 |r ) .
u OaDb
|ξ1 | + |ξ2 | 6= 0,
PDQ s
|ξ1 | + |ξ2 | (|ξ1 | + |ξ2 |)1−r |ξ2 | + ≤ |ξ1 |r + |ξ2 |r , (|ξ1 | + |ξ2 |)1−r
|ξ1 + ξ2 |r ≤ (|ξ1 | + |ξ2 |)r = =
aDb
É s
E|ξ1 + ξ2 |r ≤ Cr (E|ξ1 |r + E|ξ2 |r ) ,
¡ o Á qDÍ m
ξ 1 , ξ2 ∈ L r ,
(5.2.3)
|ξ1 | + |ξ2 | = 0,
|ξ1 | (|ξ1 | + |ξ2 |)1−r
¡ o DÑDÒ Z ¡ o Á q © XDY OÏDÐ E|ξ1 + ξ2 |r ≤ E|ξ1 |r + E|ξ2 |r .
(5.2.4)
¬®°¯²±´³µ¶³µ²·´¯
170
¹DÅ
I ξ JDÓDÔvKDLDMDNDO Æ ÇDÈ v U Borel DÕ U\²^eDV OaDb Eξ D OÉ s 5.2.2 Jensen
g(x)
D°D±
[0, ∞)
g(Eξ) ≤ Eg(ξ).
¡
(5.2.5)
Ë Ö 1: aDb ξ ×DØ 0, É (5.2.5) o UDÙ p Á qDÚ g(0), mDDÑDÒ Z D D a b ξ s D \ u D Ü ^ ² D e D V D U D Ý Þ V W Âv×DØ 0, ÉDÛ 0 < Eξ < ∞, _ (D ß àDáDâvÃDãDä “D cDå ” æD³DçDOæ 183 èDéDêD³Dë ), D V α ìDÐ s g(ξ) ≥ α(ξ − Eξ) + g(Eξ), q í © XDY OÏDÐ (5.2.5) o Z ¡ o Á D ËDÖ 2: Ü g(x) U Borel DÕ Ý _ g(ξ) JDKDLDMDN Z D P QDîDSDï Eg(ξ) D I UDðDñDZ ξ UDcDdDeDV J F (x), η U [0, 1) KDLDMDNDO F (η) }DDòD¦ c d F (x) U KDLDMDNDO Ê ¢ F F UDóDeDVDZô _ g(x) ≥ α(x − Eξ) + g(Eξ),
x ∈ [0, ∞),
−1
−1
Eξ = EF
−1
(η) =
Z
1
F −1 (x)dx,
0
Eg(ξ) = Eg(F −1 (η)) =
Ü^ ξ JDÓDÔDKDLDMDNDOõD ÷ áDD V n ≥ 2, Ú s g
F −1
U »DöDJ
n−1 1 X −1 k F n n
!
1
(5.2.6)
g(F −1 (x))dx.
0
[0, ∞).
ÜD²^eDVDU °D±DD _DOõ{
u O s
k=0
n→∞ Z 1 Z 1 g F −1 (x)dx ≤ g(F −1 (x))dx,
o û À^ü § (5.2.6) ú (5.2.7) D ùDeDV ODD°Dþ UDÿ ÑDÒ Z ¹DÅ 5.2.3 I ξ JDKDLDMDNDO 0
o (5.2.5) ZýÜ^ 0
0 < s < r,
ξ ∈ Lr
DÕ U\²^eDV Ú ø
u O s
ξ ∈ Ls ,
(E|ξ|s ) s ≤ (E|ξ|r ) r .
s (5.2.8)
Ü > 1, D g(x) D°D± [0, ∞) ¡ UDøDù\²^eDVDZ ^ JDÓDÔDKDLDMDNDO ξ ∈ L , D Ü °Dþ 5.2.2 Ð r
g(x) = x s ,
η = |ξ|s
r s
r
r
DþDêDÏDÐ
É m
Lebesque
1
1
ËDÌ Ä
(5.2.7)
n−1 1X k −1 g F ≤ . n n
a b g(x) J [0, ∞) ¡ UDøDùDeDV D O É m k=0
Z
r
r
(E|ξ|s ) s = g(Eη) ≤ Eg(η) = Eη s = E(|ξ|s ) s = E|ξ|r < ∞. (5.2.8)
o Z
§5.2
hDiDOjDhDiDkDl 5.2.1
171
DG DH I KDLDMDN
ξ U D V D y ~DD| Z DÄ Ü^ { ÷ á r > 0, Ú s 1 E|ξ| = √ 2π r
Z
∞
2
r − x2
|x| e
dx =
r
2 π
Z
∞
ξ
xr e −
x2 2
òD¦
m
0
ξ
J V Z m
n
Eξ 2n−1 = 0, ∀ n ∈ N ; r Z ∞ r Z ∞ 2 2 2 2n−1 2n−1 − x2 dx = x e 2n−1 tn−1 e−t dt E|ξ| = π 0 π 0 r r 2 n−1 2 = 2 Γ(n) = (2n − 2)!!, ∀ n ∈ N . π π
r = 2n
u OÉ s Eξ
2n
= E|ξ|
2n
=
r
2 π
Z
∞
2
2n − x2
x e
0
1 2n = √ Γ(n + ) = (2n − 1)!!, 2 π
§5.2.2
PDQ\[^]D_ ` O m Q"!"# ¬ « KvLvMvN O QDDDSDT 1 y KDLDMDN ξ ∈ L u O 2
dx =
r
2 π
Z
DD
dx < ∞,
U ÷ D DZ y | Ú D U V y ~ | ú z { ~ | Z I P Q R c ¤ ξ ô r = 2n − 1 u O D
−∞
N (0, 1),
∞
(5.2.9)
1
2n tn− 2 e−t dt
0
∀ n ∈ N.
(5.2.10)
KDLDMDN ξ ∈ L u O VDWDXDY Eξ ξ U » Z O U " »"$"%vO"& ¬ «"'"(") V WvXvYvU*vd"+", Z J " ¢^« |DOÏ µ = E|ξ − Eξ|. -D µ sDu  ô OD Q ./ ¥ SDT 2 y ¢^« | 1
1
1
Dξ = E(ξ − Eξ)2 ,
(5.2.11)
D¨ ' x ÊD J 9 KDLDMDN ξ U01 O
DJ Dξ 2 V arξ, Ê ¢ V ar 3456 Variance U78DZ ± DKDLDMDN ξ : ' <;^UDVDWDXDY Eξ $ 1DU0DU » Z Q D ./ ¥ ¨ √Dξ x J ξ U=>1 2 01DZ J #?@ 01DUDÝDÞ OPD Q ADR ¿\À ³D´BDþ Z CDÅ 5.2.1 aDb ξ JD×DØ 0 U KDLDMDNDOÉ s Eξ = 0; ó $DOaDbDKDLDM N ξ ∈ L , D Eξ = 0, É ξ ÛDJD×DØ 0 U KDLDMDN Z ËDÌ Ä aDb ξ JD×DØ 0 U KDLDMDNDOÉ s P (ξ = 0) = 1, D s Eξ = 0. ó $DO aDbDKDLDMDN ξ ∈ L , D Eξ = 0, -D ξ ÂD×DØ 0, É s P (ξ = 0) < 1. f 2
2
2
2
2
2
¬®°¯²±´³µ¶³µ²·´¯ E D δ > 0 ú 0 < ε < 1, ìDÐ P (|ξ| > δ) > ε, Eξ > δ ε > 0, FGHI Z Du ξ ÛDJD×DØ 0. D K Ä Ü (5.2.11) oJ ô D ¹DÅ 5.2.4 KDLDMDN U0D 1 ¸Ds aL ÝDÞ Ä 172
2
m
1◦ .
ξ ∈ L2
u O s
m D î m 3 .{ ξ∈L ú O V 2◦ . Dξ = 0, ◦
2
2
Dξ = Eξ 2 − (Eξ)2 ;
ξ c,
s
(5.2.12)
MNDÛ JO V OÏ D O V
c,
ìDÐ
P (ξ = c) = 1;
D(cξ) = c2 D(ξ); 4◦ .
{
ξ ∈ L2
ËDÌ Ä
ú ÷ áO V
c,
(5.2.13)
Ú s D(ξ) ≤ E(ξ − c)2 .
PDD¡DOPDQ s Dξ = E(ξ − Eξ) = E ξ − 2ξEξ + (Eξ) = Eξ − (Eξ) . Q o (5.2.12) sDu &R 0D1 US R 0TDZ 2 . Ü D B þ 5.2.1 _DO Dξ = E(ξ − Eξ) = 0 ÃU ξ − Eξ D×DØ MDNDOÏDÃU P (ξ = Eξ) = 1, D D ÐD V Z 1 U °D± Ò Ð Z 3 . Ü<0D 1◦ .
2
2
◦
◦
4◦ .
2
2
2
2
0
U KDL
PDQ s
2
E(ξ − c)2 = E ((ξ − Eξ) − (c − Eξ)) = E(ξ − Eξ)2 − 2E(ξ − Eξ)(c − Eξ) + (c − Eξ)2 = Dξ + (c − Eξ)2 ≥ Dξ.
PDQDRWMD´ 01DUXYDZ 5.2.2 Poisson cDd P (λ) U 01DZ DÄ0I KDLDMDN ξ òD¦ Poisson cDd P (λ), Ê ¢ λ > 0. PDQ\[^] X Z Ð Eξ = e P n = λ, D [\ Q o (5.2.12), ]^DÎ Z K Eξ . ¼D½ d _ OPDQ s −λ
∞
n=1
λn n!
Eξ 2 =
2
∞ X
n2 P (ξ = n) =
n=0
∞ X
n=1
∞ X
n2 e−λ
∞ X λn λn = e−λ n2 n! n! n=1
∞ X λn λn = e−λ n(n − 1) + e−λ n n! n! n=2 n=1
= λ2 e−λ
∞ X λn−2 + λ = λ2 + λ . (n − 2)! n=2
5.3.1 ξ
UDc
¢
hDiDOjDhDiDkDl Î Ü Q o (5.2.12) ÏDÐ §5.2
173
Dξ = Eξ 2 − (Eξ)2 = (λ2 + λ) − λ2 = λ .
U 01DZ 5.2.3 ` cDd N (a, σ ) DÄ0I KDLDMDN ξ òD¦D` cDd N (a, σ ), PDQ\[^] Z Ð 2
1DU °D±
(5.2.11),
2
PDQ s
Eξ = a.
abD¼D½ 0
(x − a)2 dx (x − a)2 exp − σ2 −∞ Z ∞ 1 (x − a)2 =√ (x − a)2 exp − dx σ2 2πσ −∞ Z ∞ u2 1 u2 e− 2 du = σ 2 . = σ2 √ 2π −∞
Dξ = E(ξ − Eξ)2 = √
1 2πσ
Z
∞
Ê ¢ éDêD³cDPDQD¼D½# 5.2.10 o\¢ U VDb Z ¹Dº 5.2.2 I ÓD×DØ U D K LDMDN ξ ∈ L , PDQ x 2
J
ξ
U=> ØDKDLDMDN Z
ô
ξ − Eξ ξ∗ = √ Dξ
(5.2.14)
Eξ ∗ = 0, Dξ ∗ = 0.
X a Poisson cDd P (λ) KDLDMDN ξ U=> ØDKDLDMDNDJ ξ = ; ` cDd ¢ PQ£[]_ ` O ξ , ædedf N (a, σ ) KLMN ξ Ud=d> ØKLMNJ ξ = òD¦ => ` cDd N (0, 1); ÃDÃ Z ædedf ¢ OPQdBdgd` cDdU=d> ØKDLMDNDJd# Tdhi û Z PD¡DO PDQBg => ØDKDLDMDND s ³D´D~ DZX aDO0PDQDSDT Udjk O0f E m D lDJ5mnõÐ ξ , }DDDolp5mnõÐ ξ . h s Ð ξ = 100ξ . f E üq ³rn ξ : ξ stu s DÂ ív ü mD D³D´DÂwDþ sxy v -Dz{ => Øn D|! Á} $~ s D1 ¤ n p s ξ = ξ . §5.2.3
ξ ú η í ~ s Á n ξ, η ∈ L , E Z ξ + η s 01 ∗
ξ−a σ
∗
2
1
2
ξ−λ √ λ
2
2
∗
1
1
∗ 2
∗ 1
2
2
D(ξ + η) = E ((ξ + η) − E(ξ + η)) = E ((ξ − Eξ) + (η − Eη))
2
= E(ξ − Eξ)2 + E(ξ − Eξ)(η − Eη) + E(η − Eη)2 = Dξ + E(ξ − Eξ)(η − Eη) + Dη.
d¤ d K x #dd
E(ξ−Eξ)(η−Eη),
Ü hd¡ ÷ ád¢d£
x, y,
Ú
(5.2.15) |xy| ≤ 21 (x2 +y 2 ),
¥¦§©¨«ª<¬®¬«¯<¨
174
E 5.2.3 ´
¤ ]° ²³ p
ξ
:
± v
|E(ξ − Eξ)(η − Eη)| ≤ E|ξ − Eξ||η − Eη| ≤ 21 (Dξ + Dη).
ξ, η ∈ L2 ,
E(ξ − Eξ)(η − Eη)
ξ, η ∈ L2 ,
µ
Cov(ξ, η) = E(ξ − Eξ)(η − Eη)
s ¶ 0 1 n¸·« Cov K 3456 ¹ ¶ 0 1 s º»¼ ²½ 5.2.5 ¶ 01¾ L¿À η
Covariance
(5.2.16)
s 78 v
1◦ . Cov(ξ, η) = Cov(η, ξ); 2◦ . D(ξ + η) = Dξ + Cov(ξ, η) + Dη; 3◦ . Cov(ξ, η) = Eξη − EξEη; 4◦ .
¡ÁÂ ¢£
ÃÄ ÆÅÇ
a 1 , a 2 , b1 , b2 ,
Cov(a1 ξ1 + a2 ξ2 , b1 η1 + b2 η2 ) = 4◦ .
2 P 2 P
ai bj Cov(ξi , ηj ).
i=1 j=1
Cov(a1 ξ1 + a2 ξ2 , b1 η1 + b2 η2 ) = E (a1 ξ1 + a2 ξ2 − E(a1 ξ1 + a2 ξ2 )) (b1 η1 + b2 η2 − E(b1 η1 + b2 η2 ))
= E (a1 (ξ1 − Eξ1 ) + a2 (ξ2 − Eξ2 )) (b1 (η1 − Eη1 ) + b2 (η2 − Eη2 )) 2 P 2 2 P 2 P P =E ai bj (ξi − Eξi )(ηj − Eηj ) = ai bj Cov(ξi , ηj ).
ξ , · · · , ξ È ~ s n nÊÉË·«<Ì """Í "0 "Î (»"Ï h L ), E """""Ð"Ñ"·ÒÔÓ """" s"Õ"Ö"× ·« ÁÂØ s¶ÕÖ i=1 j=1
1
i=1 j=1
n
2
bij = E(ξi − Eξi )(ξj − Eξj ).
(5.2.17)
²³ 5.2.4
n Ù «Ú< (ξ , · · · , ξ ) s Ì t Í Ï h L , E Û «Ú< s¶ÕÖÜ v n × n ÕÜ B = (b ) µpÝ ¶²Õ½ ÖÜ ¾
L¿À «Ú< t Í Ï h L , EÞ s¶ 5.2.6 nÙ (ξ , · · · , ξ ) s Ì ÕÖÜÃ"Ä B = (b ) ßà Ü v ÚÔ Þ s"ä"å v Á"æ n Ù"¢ ÚÔ "" →−x á"â n Ù"ã → − ¸ n x á"â Í → − x = (x , · · · , x ), 1
n
2
1
n
2
ij
ij
τ
τ
¤
1
n
n P n n P n P P → − − x τ B→ x = xi xj bij = xi xj E(ξi − Eξi )(ξj − Eξj ) i=1 j=1 i=1 j=1 n 2 P =E xi (ξi − Eξi ) ≥ 0,
ßà Ü v
i=1
B = (bij )
çèn¸éçèêë 175 ì 5.2.4 (íïîïðïñïòïóïôïïõïöï ) ´ (ξ, η) ÷ïøïùïÙïàï` tïu N (a, b; σ , σ ; r), ú Z (ξ, η) s¶ÕÖÜ v û «ü<ý Zþ Eξ = a, Eη = b, b = Dξ = σ , b = Dη = σ . ¤ ]^ ÿ b . ab ¶ÕÖs (5.2.16), É u= , v= , þ » §5.2
2 1
2 1
11
2 2
22
12
y−b σ2
x−a σ1
n o √ −1 R ∞ R ∞ 1 2 2 b12 = σ1 σ2 2π 1 − r2 −∞ −∞ uv exp − 2(1−r 2 ) (u − 2uv + v ) dudv.
Õ
s=
»¼
t=v
Z Z σ1 σ2 ∞ ∞ p 1 2 2 2 2 b12 = ( 1 − r st + rt ) exp − (s + t ) dsdt 2π −∞ −∞ 2 Z ∞ Z ∞ 2 t t2 1 − s2 √ e 2 ds √ e− 2 dt = rσ1 σ2 . = σ 1 σ2 0 + r 2π 2π −∞ −∞
¤ ùÙà` tu ì
u−rv √ , 1−r 2
N (a, b; σ12 , σ22 ; r) B=
s¶ÕÖÜ p σ12
rσ1 σ2
rσ1 σ2
σ22
!
.
ú t ¡X 4.2.1 × X 4.2.2 s «Ú< Ü v û ¹ h ù X s Ø tu Í Bernoulli tu ! 5.2.5
0
1
(ξ, η)
,
3/5 2/5
¤ = Eη = , Dξ = Dη = . ÿ Cov(ξ, η). X Eξ 4.2.1
9 25
X þ
4.2.2
6 25
6 25
6 25
4 25
=
4 25 .
1 10
=
1 10 .
Cov(ξ, η) = Eξη − EξEη = 0.
Eξη = 0 · 0 ·
3 10
+0·1·
3 10
+1·0·
Cov(ξ, η) = Eξη − EξEη =
3 10
1 10
+1·1·
−
4 25
3 = − 50 .
p£ s ¸n r Ç !v §5.2.4
ÿ Þ s¶ÕÖ
2 2
176
"½
5.2.2
¥¦§©¨«ª<¬®¬«¯<¨
´
ξ, η ∈ L2 ,
#
(Eξη)2 ≤ Eξ 2 Eη 2 ,
ÉË$%&ºn('Ë Å '± t ∈ R, ) þ ÃÄ +*, n ¡ÁÂ t ∈ R, Í 0
(5.2.18)
ξ = t0 η, a.s.
g(t) := Eη · t − 2Eξη · t + Eξ = E(ξ − tη) ¤ ù-.£ g(t) s/ þ0 $ (5.2.18). ∆ = 4(Eξη) − 4Eξ · Eη ≤ 0,
± t ∈ R, ) þ ξ = t η, a.s. , 12 2
2
2
2
0
2
2
≥0,
2
0
(Eξη)2 = Eξ 2 Eη 2 .
(5.2.19) &ºn¸5 Õ6 g(t) = 0 7 s ¢ [ t , » 34 n E(ξ − t η) = g(t ) = 0, h ¹ ! 5.2.1 , ξ − t η 89 h 0 s n¸» ξ = t η, a.s. . ¹ ! 5.2.2 þ: ¼; <= 5.2.1 ´ ξ, η ∈ L , #
(5.2.19)
0
2
0
0
0
0
2
Cov(ξ, η) ≤
p
p Dη,
Dξ ·
ÉË$%&ºn('Ë Å '± t ∈ R, ) þ ξ = t η, a.s. . x r>£ s ²³ 5.2.5 ´ ξ, η ∈ L , µ 0
(5.2.20)
0
p
2
ξ
?
s £ v
¹ º , η
rξ,η = E
Cov(ξ, η) √ rξ,η = √ , Dξ · Dη rξ,η = 0,
#µ
ξ − Eξ η − Eη √ · √ Dξ Dη
ξ
?
η
(5.2.21)
0 v
= E(ξ ∗ η ∗ ) = Cov(ξ ∗ , η ∗ ),
(5.2.22)
¤ @ @@d£dd@A@B@9 s d s¶dÕÖ v à @C d¤D n zd{A@B9| E ¹ h ÿ GF m s 0 ÈGHG> """GI r sGJGK v ¤ G GG"£GL"GBGMGNGO P Ø 4 ~ s v ! 5.2.1 × ! 5.2.2, Q * ¹ £ s ¼
ç èn¸éçèêë ²½ 5.2.7 ¡Á ξ, η ∈ L , Í ± a, b ∈ R, ) þ ξ = aη + b, a.s. . ÉË' r §5.2
177
2
ξ,η
|rξ,η | ≤ 1.
=1
Rn
H
'Ë Å ' = −1 Rn
|rξ,η | = 1
a > 0;
'
rξ,η
a < 0.
¡ÁÂS 8 9 s ξ, η ∈ L , T UV W$X 0 Y (1) ξ ? η (2) Cov(ξ, η) = 0; (3) Eξη = EξEη ; (4) D(ξ + η) = Dξ + Dη. 0 v 4 rZ; ?[º¿ ~ s ²½ 5.2.9 ¡ÁÂS 89 s ξ, η ∈ L H\n
ξ ? η [ºn 5 Þ 0 Y(]
Þ 0 ^_`W[º v ÃÄ
ξ, η ∈ L , ÉËW[ºn¸512 ²½
5.2.8
2
2
2
¤ Þ 0 v 34 n¸ 3 a ì 5.2.6 ´ ξ × η s tubt p !
Cov(ξ, η) = E(ξ − Eξ)(η − Eη) = E(ξ − Eξ) · E(η − Eη) = 0,
ξ∼
−1
0
1
1 2
1 4
1 4
η∼
,
0
1
1 2
1 2
!
(5.2.23)
# ξ ? η 0 [ºn(c 0 v û ¹ ξ × η s"t"uGb n , Eξ = Eη = 0. dGe"p P (ξ · η = 0) = 1, ¤ 0 v ] E(ξ · η) = 0. ef Cov(ξ, η) = E(ξ · η) − Eξ · Eη = 0, , ξ ? η ÉË ¤
P (ξ · η = 0) = 1.
P (ξ = 1) = 14 ,
P (η = 1) = 12 ,
P (ξ = 1, η = 1) ≤ P (ξ · η = 1) ≤ P (ξ · η 6= 0) = 0,
P (ξ = 1)P (η = 1) = 6= 0 = P (ξ = 1, η = 1), 0 g ξ ? η [º v h ¢n( ξ ? η s tu×ij P (ξ · η = 0) = 1, 0kl w tub 1 8
pij
-1
0
1
pi·
0
1/4
0
1/4
1/2
1
0
1/2
0
1/2
(ξ, η)
sm
1/2 1/4 1 n ij P (ξ · η =p0) = 1/4 ¹
3 ao v ·pq 1, ¼ w t u b m t u b s rs sw Î$x 0 s m å t « á u t v p × p , Ø 0, 2 y i z 4 × $x p , y j ã 4 × $x p , ¼ {·|Ó} s ì ~v θ ÷ø tu U (0, 2π), H 5.2.7 ´ ·j
i·
·j
·j
i·
ξ = cos θ,
η = cos(θ + a),
¥¦§©¨«ª<¬®¬«¯<¨
178
·« a p £n( v 0k
Eξ = Eη = 0; Dξ = Dη = 21 . R 2π 1 Eξη = 2π 0 cos x cos(x + a)dx =
¤ n
1 2
cos a.
rξ,η = cos a.
1◦ . 2◦ .
¿Y
a = 0, a = π,
#
fR ξ = η = cos θ, Þ pÈ Y Þ 4 ~ M s = −1, fR η = cos(θ + π) = −ξ, Þ 0 v ] ξ = cos θ, η = sin θ, = 0, fR
rξ,η = 1,
#
rξ,η
a = , # r r Ç Þ 0 W[º v , n
Þ W[ºn¸5 ¡ÁÂ π 2
3◦ .
ξ,η
B1 , B2 ∈ B 1 ,
Ý Í
P (ξ ∈ B1 , η ∈ B2 ) = P (ξ ∈ B1 ) P (η ∈ B2 ) .
x æ
B1 = B2 = (0, 21 ),
5
(η ∈ B2 ) = 0 < sin θ
ef12 þ
1 π 2 = 3 <θ < < 21 = 0 < θ <
(ξ ∈ B1 ) = 0 < cos θ <
π 3π 2 ∪ 2 π 5π 6 ∪ 6
(5.2.24)
<θ<
5π 3
;
<θ<π .
(ξ ∈ B1 ) ∩ (η ∈ B2 ) = Φ,
P (ξ ∈ B , η ∈ B ) = 0, 0 0 ¤ gfR (5.2.24) & ºn ξ ? n η [º v h ¢0 nfR Þ4~ ±0 S ¿ v ξ + η = cos θ + sin θ = 1. s W[º wZ; , (£ r ¡ ξ ? η s ¿ s O P ' |r | : ~ 1 R ξ ? η 4 ~`2± ¿Y' r : ~ 0 R ξ ? η 0 ¸» Þ 4 ~ 0 ± ¿GG(] Þ 4 ~G 2±· ¤ É 0 W[º ] ¡ xùÙà^ a ( ²½ 5.2.10 d
dÚ (ξ, η) m@¡ @ddùdÙdà@@@ N (a, b; σ , σ ; r), # ¢ UV W$X 0 1 . ξ ? η W[ºY 2 . ξ ? η Y 3 . r = 0. ÃÄ ¹ x[º 0 ¤ 1 ⇒ 2 . ¹ a 5.2.4 ÿ£
, P (ξ ∈ B1 ) = P (η ∈ B2 ) = 61 ;
2
2
2
1
2
2
ξ,η
ξ,η
ξ,η
2 1
◦
◦
◦
◦
√ (ξ,η) = rξ,η = Cov DξDη
◦
rσ1 σ2 σ1 σ2
= r,
2 2
çè¸éçèêë 179 ¤ ξ ? η 0 GG¸» r = 0 $GXGx r = 0. "þ 2 ? 3 $GXG(HG' r = 0 R (ξ, η) m¡¤¥ $x Ø ¤¥ w Î ¤ fR ξ ? η W[º» 3 ⇒1 . :§¦ C¨©(«ü<ýª«¬ùÙà N (a, b; σ , σ ; r) ¤ 5 £ ® §5.2.5 ¯°±²³ô´µ³õö """"G¶ G GGWG["ºG """ ¸÷"ø"È ´ ξ, ξ , ξ , · · · """"È F (x).
· §5.2
◦
ξ,η
◦
◦
◦
2 1
1
2 2
2
S0 = 0,
Sn =
n X
n ∈ N,
ξk ,
µ¨ i.i.d.([ºÈ ) ¸ ã {ξ , n ∈ N } ¹ × º«ü<ý , S .£¨ I(x > 0); H S .£¨ F (x), ·« F (x) F (x) n »§¼¾½Î(¨ Õ¿À g(· F (x) = I(x > 0), ɵ·¨ F (x) 0 »§¼¾½ Î
ξ ∈ L , ÉË Eξ = a, 5Q * þ 5
k=1
Sn
n
0
∗n
n
∗n
∗0
1
Á Â
ES0 = 0,
n P
ESn =
n ∈ N.
Eξk = na,
þ ξ ∈ L , ÉË Dξ = σ , 5Q * P DS = 0, DS = Dξ = nσ , n ∈ N . Ã ´ ν ? ¸ ã {ξ , n ∈ N } È ¶ Ä æ S@ÅÆ £ ~ ddd ÉdË ν @? ddd@¸ ã {ξ , n ∈ N } @W@[dº@Ç@dµ k=1
2
2
n
0
n
2
k
k=1
n
n
Sν =
ν X
ξk =
∞ X
Sn I(ν = n).
(5.2.25)
¸ ã {ξ , n ∈ N } È A × (ɵ¨ × ÊC ïÊÊËʦ Ì ÍÎÊÐÏ ýÊÑ@n ÒÊÓ dï × Ê a dd
@ ¸ {ξ , nd∈
N } ádâdÓ@Ôd±@Õ@ d£ Ø@Ùu5Ú d: Ö@¨ [dºÈ@@ ã@ ~ æ S Å Æ ν á â¸×ÉzË ¡ ! NGÖ¨ ±ν ÕÔ? £¸5 ¸ ν ã '2{ξ , n ∈Ä N } W[£ º( x ÙuÚ : ±Õ£ ¦ (5.2.25) ¤ â × S . (×z Ø ÛÜ l S .£(Ý n=0
k=1
i.i.d.
n
n
n
ν
ν
$% þ ¼¾[º¿¸øH ¹uÞ ß þ ·«
P (Sν < x|ν = n) = P (Sn < x|ν = n) = P (Sn < x),
FSν (x) = P (Sν < x) = P (
ν X k=1
ξk < x) =
∞ X
n=0
P (Sν < x|ν = n)P (ν = n)
¥¦§©¨«ª<¬®¬«¯<¨
180 ∞ X
=
P (Sn < x)P (ν = n) =
∞ X
P (ν = n)F ∗n (x).
(5.2.26)
à ´ ξ, ν ∈ L , ÉË Eξ = a, Eν = u, Ü ÿ .£(áÓ£âãä Ü ÿ ¸5 n=0
n=0
ESν .
1
ESν = = =
Z
∞ X
n=0 ∞ X
∞
xdFSν (x) =
−∞
P (ν = n)
(5.2.25)
ESν = E ∞ X
∞ X
xd
−∞
P (ν = n)F ∗n (x)
n=0 ∞ X
xdF ∗n (x) =
−∞
ν X
ξk =
∞ X
Sν
!
P (ν = n)ESn
n=0
(5.2.27)
× £âãä ¿ÀÜ ÿ E (Sn I(ν = n)) =
n=0
k=1
=
∞
∞
P (ν = n)na = Eνa = ua.
n=0
cá
Z
Z
ESν :
∞ X
ESn EI(ν = n)
n=0
naP (ν = n) = a
∞ X
nP (ν = n) = aEν = au.
Ã à ´ ξ, ν ∈ L , É"Ë Eξ = a, Eν = u, Dξ = σ , Eν DS . å® ES = DS + (ES ) = nσ + (na) . þ æ Õ ¹ á (5.2.25) n=0
n=0
2
2
2
= τ 2,
GGÜ ÿG
ν
2 n
Sν2 =
ν P
n
2
ξk
n
∞ P
=
2
2
2
2
Sn I(ν = n)
=
∞ P
Sn2 I(ν = n),
0 Gçè h j ¤ R (ν£ é = n ) ? G (ν = n ) GW n )I(ν = n ) = 0. ¸º» l þ n GeG¨G' 1
n=0
k=1
n1 6= n2
n=0
1
2
2
ESν2
=E
∞ X
Sn2 I(ν
= n)
n=0
= σ2
∞ X
!
nP (ν = n) + a2
¡ ¸» þ
n=0
=
∞ X
∞ X
ESn2 P (ν
= n) =
n=0
∞ X
n=0
nσ 2 + (na)2 P (ν = n)
n2 P (ν = n) = uσ 2 + a2 τ 2 .
n=0
DSν = ESν2 − (ESν )2 = uσ 2 + a2 τ 2 − a2 u2 = uσ 2 + a2 Dν.
1.
I(ν =
êë
ìºíºîºïºð ξ ºñ òºóºôºõºö p(x) =
(
5.2
1 x e , 2 1 −x e , 2
x≤0 x>0
,
(5.2.28)
ç è¸éçèêë ÷ºø |ξ| ùºúºûºüºýºþºÿ 2. ìºíºîºïºð ξ ñºòºóºôºõºö
§5.2
181
pξ (x) =
÷ºø
η = eξ
þ
ζ=
1 ξ
(
2(x − 1),
1<x<2
0,
ùºúºûºüºýºþºÿ
ø Eξºíºþ îDξ:
3. (1)
ξ
,
ºùùú ÷
ξ
ùºóºô
“THE GIRL PUT ON HER BEAUTIFUL RED HAT.”
(2) ù 30 !íî ! ºú ÷ η ùºóºô ø Eη þ Dη. 4. ìºíºî#" ð (ξ, η) ñºòºóºôºõºö p(x, y) =
÷ºø
(
2e−(x+2y) , 0,
η
ù
x > 0, y > 0
,
$ %&ºú ) þ E(ξ − Eξ) . 5. '()*+,$-ð.'/ù0ð12304-ð56789:-ð;<ù=> ?@ $A'/ºù0ð ÷BCDEF ùG( ÷L “M ”a , a , · · · , a (NOP 6. Híîïð ξ , ξ , · · · , ξ IJK íîïð Dξ = σ , P ) ú ), S P a ξ ùºÿ7T a = 1 ù n !QRº 7. ìíîïð ξ , ξ , · · · , ξ (n > m) IJK ù+ òU V ù W òò X ùÿY ÷ø S = ξ + ··· +ξ Z T = ξ +ξ + ··· + ξ [\]^ ùU_º` ú ÷ d 8. H ξ ùºõºöaºú Ib aºúcW Eξ < ∞, |ξ| Z ξ eU_fgheUi JK 9. H (ξ, η) ùºõºöº a ú$ Eξ k , E(ξ k η l ) (k, l
1
n
2
3
n
2 i
i
n
i
1
2
n
i i
i=1
i=1
1
2
1
m+n
n
m+1
m+2
m+n
2
p(x, y) =
(
1 , π
0,
x2 + y 2 ≤ 1
x2 + y 2 > 1
÷ *kjlm ξ Z η e U_fghe JK ? º 10. H ξ Z η n Io [ ! ù íî÷ïd ð ÷dpq gheU_cr JK 11. H η = aξ + b, η = cξ + d, η , η ùU_`ºúst ξ , ξ ùU_`ºú 12. H ξ , ξ , ξ I íºîºïº ð ÷ uvp wx ]^ ù_`m 1
1
1
2
2
2
1
2
1
2
3
[[ eU_y (2)D(ξ + ξ + ξ ) = Dξ + Dξ + Dξ ; (3)Eξ ξ ξ = Eξ · Eξ · Eξ . Eξ = a, Dξ = 1, Eη = b, Dη = 1, dC m ξ Z 13. H ξ, η z{|}%~ úst r cos qπ, q= P {(ξ − a))η − b) < 0}. 14. ì (ξ, η) z{|}%~ Eξ = Eη = 0, Dξ = Dη = 1, r = r, ÷d (1)ξ1 , ξ2 , ξ3 1 2 3
1
1
2
2
3
1
2
3
3
ξη
E max(ξ, η) = 15.
ak = E|ξ|k ,
H
an < ∞,
÷d
√ k a ≤ k
r
1−r π
√ ak+1 , k = 1, 2, · · · , n − 1.
k+1
η
ùU_`
182
H
16.
ξ
ùºõºöaºú$ p(x) =
÷d t
17. 18.
z{ N (a, σ ), ÷ºø Pareto ùºõºöºa ú$ H
(
20. 21.
0,
|x| > e
,
a > 0, E|ξ|a = ∞. 2
ξ
E|ξ − a|k .
p(x) =
19.
1 , 2|x|(log |x|)2
(
1 rAr xr+1 ,
0,
x ≥ A,
x < A,
D r > 0, A > 0. ÷D ò p W p < r. òø 1 2 ù n { m ÷ (1) ò ¢¡£y (2) e ¢¡ (m ≤ n) |ø¤¦¥§ m § ]#\ ªùº«ÿ¬ 5.1 ù¨ 21 ©
ºù®ú ξ ùºÿ ìºíºî#" ð (ξ, η, ζ) ò¯°ºõºö ø± íºî#" ðºù²ÿ³p(x, y, z) = (x + y)ze , 0 < x, y < 1, z > 0. ø º ò N ´µ¶#·º µ ú τº $ íºîºïºð E(τ ) = n. {ºò #¡¸ m ´µ ·µº ´ ú ξ ùºúºûºüºý ì A, B I¹ * E º ù ([ ´º»W P (A) > 0, P((B) > 0, ¼º½ íºîºïºð ξ, η p m 1, H A¾¿ , η = 1, H B¾¿ , ξ= 0, H Ae¾¿ 0, H B e¾¿ ÷dC mH ρ = 0, r ξ Z η À¼Ui JK ì Eξ < ∞, a I¹ úÁ ( ξ, X ≤a , η= a, X >a dC m Dη ≤ Dξ. ì p (x), p (x) $ º} õºöºa ú p(x, y) = p (x) · p (y) + h(x, y). (1) $S p(x, y) Â$|º } õºöº a ú h(x, y) ÀÃW oÌ Ä OPÅÆÇ»ÉÈ (2) $S|}ºõºöaºú p(x, y) ù [ ´ }Ê˺õºö $ p (x) \ p (y), h(x, y) ÀÃW oÄ pOq PÅÆÇ»ÉÈ (3) íºî#" ð (ξ, ζ) p(x, y) @ $¯º° õºöÍ$S ξ Z η Ui JK h(x, y) ÀÃW oÄ pOq PÅÆÇ»#È (3) íºî#" ð (ξ, ζ) p(x, y) @ $¯°ºõºöÍ$S ξ Z η eU_ h(x, y) ÀÃW o Ä OPÅÆÇ»#È −z
22. 23.
ξη
24.
25.
2
1
2
1
2
1
2
Î ÏÐÑÐÒ Ð ÓÕÔÕÖÕ×ÕØÕÙÕÚÕÛÝÜßÞÕàâáÕãÕäÕåÕæÕçÕèÕéÕêÕë#ìÕíÕîÕïÕðÕñÕòÕÖÕ×ÕóÕôÕê õ÷öùøúæúÙúÚúûúüúëýúØúþúêõúÿúæ ñ úë Ó Ø ú å æ §5.3
æ Üë#øëÙÚÛêõáçèæûü! õ §5.3
183
" #$%&'( )+*+++,+-+.+/+0+ + ++ æ Ù+1+!2 ξ η Ø ä ü++3+4+5 Ù Ú+6+7 æ95 ë: i = √−1, ó; (Ω, F, P ) 8 <Ø4 5 äü ÙÚ67 (Ω, F, P ) ζ8 :=æξ/+0iη !#Ó=ë>?@× t, §5.3.1
eitξ = cos ξ + i sin ξ
Ø45/0 !
(5.3.1)
A BC /0 ζ = ξ + iη D FEG æ×KLMNë#ó;< ABOPQ RS η T I J/0 ζ A[ Ö× g g Mõ 1
'( ]
5.3.1
Eζ = Eξ + Eη; 1
= ξ1 + iη1
ζ2 = ξ2 + iη2
,å!GHIëGIJ äü Eζ (ξ, η)
UV úëXWYZW>?
ξ
Borel
2
2
E (g1 (ζ1 )g2 (ζ2 )) = Eg1 (ζ1 )Eg2 (ζ2 ). F (x)
4\ñòÖ×ëS
f (t) =
æ ÓÔÖ×!IJ æÓÔÖ×ëabõ F (x)
(5.3.2)
Z
∞
eitx dF (x),
−∞
F (x)
Ø
t∈R ξ
(5.3.3)
æñòÖ×ë^_
f (t)
` ]
ξ
cGad,ë#ÓÔÖ×<ØñòÖ×æ Fourier e! cf>?ú@ × t úM õ |e | = 1, g B >?úñúòúÖú×úæúÓúÔúÖú×MN!hcùÓúÔ Ö×æäüijklmIJnop ξ æñòq P (ξ = a ) = p , n ∈ N , ó; f (t) = Eeitξ .
itx
n
IJrsp
f (t) = Eeitξ =
ξ
ætuÖ×
f (t) = Eeitξ =
∞ X
n
eitan pn .
(5.3.4)
eitx p(x)dx.
(5.3.5)
ó;
n=1
p(x), Z ∞
õb AB ñÓÔÖ×æ@v w vxyz{ëabõ −∞
,z{4|}ñòæÓÔÖ×!
f (t) = Eeitξ = E cos tξ + iE sin tξ.
184
~FG
FG
5.3.1 }nopñòæÓÔÖ×! (5.3.4), AB {l
a
æ æÓÔÖ×
Ó=úë 0 æ úæúÓúÔúfÖú(t)×= e f (t); = 1; × ñòæÓÔÖ× ita
49ñò (ñò Ó=ëIJ
f (t) = q + peit ; P (ξ = a) = p, P (ξ = b) = q, p + q = 1)
æ
^õ
P (ξ = 1) = P (ξ = −1) = 21 ,
æÓÔÖ× P (λ)
f (t) =
∞ P
f (t) = e−λ
æÓÔÖ× G(p)
eit +e−it 2
n=0
f (t) =
∞ P
= cos t;
(eit λ)n n!
= eλ(e
it
−1)
;
peit 1−qeit .
eitn pq n−1 =
5.3.2 ×ñò exp{λ} æÓÔÖ×! (5.3.5), Y ñÓÔÖ×æ@v w vxyz{ë A n=1
f (t) = λ
ñvñëk aë
Z
∞
e−λx cos txdx + λ
0
:= λ (J1 (t) + iJ2 (t)) .
J1 (t) = λt J2 (t),
J (t) = æ Ó ÔÖ× exp{λ}
g B ×ñò
1
f (t) = λ (J1 (t) + iJ2 (t)) =
J2 (t) =
"#$%& ' 5.3.1 >?ñòÖ×æÓÔÖ×
1◦ . |f (t)| ≤ f (0) = 1, ∀ t ∈ R; 3◦ . f (t)
R
8 4¦rs¥
¢ Ü
e−λx sin txdx
0
t λ2 +t2 .
λ(λ + it) λ = = 2 2 λ +t λ − it
§5.3.2
2◦ . f (−t) = f (t), ∀ t ∈ R,
∞
1−λJ1 (t) . t
J2 (t) =
λ λ2 +t2 ,
Z
f (t)
Ø
f (t)
1−
it λ
−1
MêõI¡l
f (t)
æ/£¤¥
Bernoulli
æÓÔÖ×
f (t) = peita + qeitb ;
ñò Poisson
?ñò
0
.
§5.3
FG
êõ§¨äë#û>? 5/× z , · · · , z , Mõ 4◦ . f (t) 1
©ª l
n
5@×
t 1 , · · · , tn
1◦
n X n X j=1 k=1
2◦
zj zk f (tj − tk ) ≥ 0;
n
A cäü«¬!®¯
3◦ .
(5.3.6)
>°@× t
∆t,
õ
Z ∞ i(t+∆t)x |f (t + ∆t) − f (t)| ≤ − eitx dF (x) e −∞ Z ∞ ∆t i(t+ 21 ∆t)x i ∆t = e e 2 x − e−i 2 x dF (x) −∞ Z ∞ ∆t = 2 sin x dF (x). 2 −∞
A °²ñ³æ
´
ε > 0, A > 0, Z Z ∆t ε dF (x) < ; 2 sin x dF (x) ≤ 2 2 2 |x|>A |x|>A
°äæ
AB °¶·¸æ
| sin u| ≤ |u|, A > 0, |∆t|, Z Z ∆t ε 2 sin x dF (x) ≤ |∆t| |x|dF (x) < . 2 2 |x|≤A |x|≤A
¹º 8» ë
f (t)
R
8 4¦rs!¼¯
4◦ .
2
f (t) = Eeitξ ,
´
2 n X zj eitj ξ ≥ 0. zj zk f (tj − tk ) = E j=1 j=1 k=1
n X n X
' 5.3.2 Q Ö×æÓÔÖ×ëõI¡½Ûl f (t) = e f (bt). ©ª ¿l ¾@ 8 ëõ ita
a+bξ
ξ
fa+bξ (t) = Eeit(a+bξ) = eita Eeitbξ = eita fξ (bt).
äå 5.3.2 AB =z{>?ÀÁñòæÓÔÖ×! 5.3.3 2 ξ ÂÃ ÀÁñò U (a, b), ÄÅ ξ æÓÔÖ×! Æ l¿Ç2 ξ ÂÃ ÀÁñò U (a, b), È
^j cG
>û
n
>û±äæ ïµ
>û
n ∈ N,
185
ÀÁñò η ÂÃ fη (t) =
1 2
, i j U (−1, 1). Å R
η=
2 b−a
ξ−
1 itx dx −1 e
ξ=
a+b 2
=
+
a+b 2
eit −e−it 2it
b−a 2 η,
=
sin t t .
~FG
FG
186
g B c äå 5.3.2 f (t) = e t) = . f ( ,ÉÛÓÔÖ×æ Taylor ÊË ë a* D |ÌÍ! Î 5.3.1 4Ï x ∈ R ÐÑ× n, õ i a+b 2 t
ξ
©ª l¿W
η
b−a 2
eibt −eiat it(b−a)
n |x|n+1 ^ 2|x|n ix X (ix)k . e − ≤ k! (n + 1)! n!
(5.3.7)
k=0
n=0
bë4Òëøíõ
ix e − 1 ≤ 2;
Ó 4Òëj}
ix R R e − 1 = i x eiu du ≤ |x| du = |x|. 0 0
n = 0 bÔ!¿Ç2_ gæBØÙ(5.3.7) !ÚûabFÕG×õ
n=m
bÖÕf×Ôúë¿,d
n = m+1
m |x|m+1 ix X (ix)k . e − ≤ k! (m + 1)!
g B ëk
(5.3.8)
k=0
m m+1 |x|m+1 2|x|m+1 ix X (ix)k ix X (ix)k ≤ . ≤ e − + e − k! k! (m + 1)! (m + 1)!
Ó 4ÒëÚûk
k=0
k=0
ë A
eix − 1 = i
Rx 0
eiu du,
(ix)k+1 (k+1)!
=i
Rx 0
(iu)k k! du,
(5.3.8) Z ! Z m m m+1 x |x| X (ixu)k iu X (ixu)k ix X (ix)k iu e − du ≤ = i e − du e − k! 0 k! k! 0 k=0 k=0 k=0 Z |x| um+1 |x|m+2 ≤ du = . (m + 1)! (m + 2)! 0
¹º 8»Û ½Jë (5.3.7) n = m + 1 bÔ! n = 0, 1, 2 bæØÙÜ ë g B êÝÈîl (5.3.7)
cG>?
ix e − 1 ≤ |x| ∧ 2; 2 ix e − 1 − itx ≤ x ∧ (2|x|); 2 2 3 ix x |x| e − 1 − itx + ≤ ∧ x2 . 2 6
x ∈ R, (5.3.7)
æÞß
n→∞
bMà
(5.3.9) (5.3.10) (5.3.11) 0,
g B k
FG áâ 5.3.1
§5.3
187
eitx =
∞ X (itx)k
k!
∀ t, x ∈ R.
,
(5.3.12)
ÉÛÓÔÖ×æ Taylor ãËäåæ ! ' 5.3.3 IJ ξ æ>ûçèMNë Y t ∈ R ´
(5.3.7)
^
k=0
(5.3.12)
æÓÔÖ×êõ ÊË
ξ
|t|n E|ξ|n = 0, n→∞ n! lim
f (t) =
©ª l¿aéêë
∞ X (it)k
k!
(5.3.13)
Eξ k .
(5.3.14)
ì ¡ ë í z k=0
(5.3.13) n X (it)k k Eξ = E f (t) − k!
eitξ
k=0
k=0
|t|n+1 E|ξ|n+1 ≤ → 0, (n + 1)!
A
(5.3.7) ! n n X (itξ)k itξ X (itξ)k − ≤ E e − k! k! k=0
n → ∞.
Ô! ,z{¨îñòæïðñò! 5.3.4 õlǫ́î ñò N (0, 1) æïðñò
g B õ
(5.3.14)
t2
¨îñò
f (t) = e− 2 .
N (a, σ 2 )
(5.3.15)
æïðñò
f (t) = eita−
Æ l¿)*z{ǫ́îñò
σ 2 t2 2
.
(5.3.16)
æïðñò!ôcGïðñòæäü
N (0, 1) Z ∞ 1 x2 f (t) = √ exp itx − dx, 2 2π −∞
I J«¬z{ëõ^öz{F÷Gøñ!õ, äå 5.3.3 Üæ ÊË !+cGóÌ ¨î ξ ææ>ûçèMNë YFcGH 5.2.1 l g B >?
Eξ 2n−1 = 0, ∀ n ∈ N ; q E|ξ|2n−1 = π2 (2n − 2)!!,
∀ n ∈ N.
Eξ = E|ξ| = (2n − 1)!!, ∀ n ∈ N . ê ë Mù¶ëéaFcäå 5.3.3 t ∈ R, (5.3.13)
f (t) =
2n
2n
2 k ∞ ∞ ∞ X X (it)k k X (it)2k 1 t t2 Eξ = (2k − 1)!! = − = e− 2 . k! (2k)! k! 2 k=0
k=0
k=0
~ FG
FG W η Âà ¨îñò N (a, σ ) bë ¢ óÌ η Âà ̨îñ ò N (0, 1), Y η = a + ση , g B n o f (t) = e f (σt) = exp ita − . ,±ïðñò æ Aú êë! 2 ξ ëIJ k ∈ N , õ E|ξ| < ∞, ^ ξ æïðñò ' ç 5.3.4 Aú ë Y õ f (t) k 188
∗
2
∗
η
ita
σ 2 t2 2
η∗
k
©ª l¿*ûü c
f (k) (0) = ik Eξ k .
1
(5.3.17)
çýò!õ
f (t + ∆t) − f (t) ei∆tξ − 1 − i∆tξ − E(iξeitξ ) = E eitξ . ∆t ∆t
(5.3.10) i∆tξ 2 itξ ei∆tξ − 1 − i∆tξ − 1 − i∆tξ E eitξ e ≤ 2|ξ| ∧ |∆t|ξ , ≤ E e ∆t ∆t 2 E|ξ| < ∞,
Y
|∆t|ξ 2 2
|∆t|ξ 2 2
Bg c Lebeaque þÿ äå f (t) N→0,ë ∆tYõ → 0, cGa ë (5.3.17)f (t)! = E(iξe ). WÚûëf_äåæïÔ!f¾@ 8 ëfIJ f (t) æ 2k çýòNëf A B ξ æ 2k çèN# ýØW f (t) æ 2k + 1 çýòNbë ξ æ 2k çèN!® ï Û! c 8» äåë AB kïðñò t = 0 æ Taylor ÊË l áâ 5.3.2 2 ξ ëIJ n ∈ N , õ E|ξ| < ∞, ^ ξ æïðñò t = 0 AB ÊË f (t) 2|ξ| ∧
≤
0
0
itξ
n
f (t) = 1 +
n X (it)k k=1
k!
Eξ k + o(tn ),
t → 0.
(5.3.18)
©ª l¿éW E|ξ| < ∞ bëõ E|ξ| < ∞, k = 1, · · · , n, (5.3.17) Taylor ÊË äå (5.3.18) ! â §5.3.3 "#$%& Õ × ä å 5.3.1 Ü É Û ï ð ñ ò æ ë õ b | AB = ä 4 5 ñ ò Ø ï ð ñò ! HIl f (t) = sin t ïúØ ï ð ñ ò ë é f (0) = sin 0 = n
k
§5.3
FG
189
ýúØúë õ b ï! HIl “ g(t) = | cos t| ØúØïðñò ” 5 ,<úÿúïij! j g(t) = | cos t| 4¦rsúë |g(t)| = | cos t| ≤ 1 = g(0), ý Øúþúïij¯úîú Ø úêúõÐä! Wíúë IJ !öùîïêúõÐäë ó;"í AB úäúîú Ø ïðñò A Ø IJ¯ö æ îúêõÐäëþ# B$ äî Ø ïðñò!é % õ ¯ö _äåÝÜæ ê ` Ø45 ñò f (t) Ø ïðñòúæ ²úñ êëúë g B ×öú& è fkïðñòæúäüë ddú Ø N45 ñòñò F (x), ´ (5.3.3) Ô ('( N45 ξ, ´ f (t) = Ee ). 5.3.5 ¯öë ñò g(t) = | cos t| ïØ ïðñò! ©ª l¿Ç2 g(t) = | cos t| Ø ïðñòë#ó ;<Nñò ñò G(x), ´ 0 6= 1.
itξ
g(t) =
W
t=π
bëk
° ¢ @vë cf
Z
∞
−∞
g(π) =
R∞
−∞
∞
∀ t ∈ R.
(5.3.19)
eiπx dG(x) = | cos π| = 1,
cos πxdG(x) = 1 .
(5.3.20)
ïúØ)òbúë õ cos πx < 1, R dG(x) = 1, g B (5.3.20) ÔëfWYZW G(x) nopñòë Y ¢*+ ,-.)ò, º ì ÜG!f2 ξ ÂÃ ñò G(x), / p = P (ξ = 2n), ¢ Ü n Ñò!#ó;<õ cos πx ≤ 1,
YW
Z
eitx dG(x) = | cos t|,
−∞
∞ −∞
x
2n
(5.3.19)
∞ X
<Ø ∞ X
g(t) =
ï=ë#õ 8 S _
n=−∞
g
π 2
ei2nt p2n = | cos t|, ∞ P
=
n=−∞ ∞ P
½ º ëk (5.3.21)
Ó 4Òë T c
p2n = 1 ;
(5.3.21)
n=−∞
k=−∞
p4k =
∞ P
k=−∞
(5.3.22) g
π 4
=
∞ P
∞ X
e
p4k+2 = 0 .
k=−∞
k=−∞
n=−∞
(5.3.22)
einπ p2n = cos π2 = 0 .
p4k −
∞ X
∀ t ∈ R.
inπ 2
p4k+2 =
1 . 2
p2n = cos π4 =
(5.3.23)
√ 2 2
,
~FG
FG
190
_ ∞ P
p8k −
∞ P
p8k+4 =
√ 2 2
.
< õ à P P P > . p = p + p ≥ a (5.3.23) U01 ! g B g(t) = | cos t| ïØïðñò! 5H2 à 45Ò3÷öùë öè45úæ67,8ïðñò! ) *,É9 UV æ ì æïðñò! ' 5.3.5 IJ ξ ξ UV ë^õ k=−∞
∞
4k
k=−∞
∞
k=−∞
∞
8k
k=−∞
√ 2 2
8k+4
k=−∞
1
1 2
2
fξ1 +ξ2 (t) = fξ1 (t)fξ2 (t).
(5.3.24)
©ª l ïðñòæäü òKLæë fξ1 +ξ2 (t) = Eeit(ξ1 +ξ2 ) = Eeitξ1 Eeitξ2 = fξ1 (t)fξ2 (t).
c 8 » äåkl áâ 5.3.3 I J f (t) : ï ð ñ òÕë#ó ; > ?
M : ï ð ñ ò! ©ª lfcG f (t) : ïðñòë g B N ξ, ´ f (t) = Ee . ®Ç 2 ξ , · · · , ξ UV ë YM ξ 3ñòë#ó;<õ f (t) = Ee = Y f (t), k = 1, · · · , n, n ∈ N , f n (t)
itξ
1
n
itξk
ξk
n n P Q E exp it ξk = fξk (t) = f n (t).
¯öëñò g(t) = cos t : ïðñò! 5.3.6 9ñò P (ξ = 1) = P (ξ = −1) = Æ lcG f (t) := cos t = :  à ; ξ ; ïðñò ë g(t) = f (t), g B g(t) : ïðñò! 5.3.7 ÄÅÛ< ñò B(n, p) ; ïðñò! Æ l2 ξ ÂÃÛ< ñúò B(n, p). ó;<N n 5 UV ; 3 Âà ò pBernoulli ξ , · · · , ξ , ´ ξ = ξ +· · ·+ξ . c ξ , · · · , ξ ; ï ð ñ ò M : f (t) = q + pe , ¢= q = 1 − p, g B ξ ; ïðñò : g(t) = f (t) = q + pe . áâ 5.3.4 IJ f (t) : ïðñò#> ó; |f (t)| `: ïðñò! ©ª lfcG f (t) : ïðñò> g B N ξ, ´ f (t) = Ee . ®2 ξ 3 ñò>: η
k=1
k=1
2
eit +e−it 2
1 2
2
1
n
1
n
it
1
n
it n
n
2
itξ
ó;<õ
ξe = ξ − η, fe (t) = Eeit(ξ−η) = Eeitξ Ee−itη = f (t)f (−t) = f (t)f (t) = |f (t)|2 , ξ
(5.3.25)
§5.3
FG
191
gB ! |f (t)| `?: ï ð ñ ò !ôc (5.3.25) g?@ ü ; ] ξ ; ] IJ {f (t), n ∈ N } : 4Aïðñò> {p , n ∈ N } : 45no 5.3.2 ' ( ñòq> õ 2
n
n
∞ P
pn ≥ 0,
ó;]
pn = 1,
n=1 ∞ P
f (t) :=
pn fn (t)
: ïðñò ;&B º ! ' 5.3.6 ïðñò ;&B º C : ï ðñò! © ª l c {f (t), n ∈ N } : 4A ï ð ñ ò> g B N 4ADEñ ò N }, ´ n=1
n
R∞
cGDEñò ;&B ºC : D Eñòe> g dFB (x), ∀ n ∈ N , P F (x) := p F (x) 4 5 D E ñ ò ! F : fn (t) =
itx
−∞
{Fn (x), n ∈
n
∞
n n
n=1
f (t) =
∞ X
pn fn (t) =
n=1
∞ X
pn
n=1
Z
∞
e
itx
dFn (x) =
−∞
Z
∞
e
itx
d
−∞
∞ X
pn Fn (x)
n=1
!
=
Z
∞
eitx dF (x),
−∞
: ï ðñò! GH 5.3.4 ¶ó ; ïðñò : ïðñò ;&B º ! © ª lm2 ξ, ξ , ξ , · · · :?@?I 3 4 5?J?K 6 7 8 ; U V ; ?> Â Ã7 34; 5 D°EÐ F Ñ(x).ò0 ; 2 ν : > Y LA {ξ , n∈NL} A @I 345JK6 ν: {ξ , n ∈ N } UV
8 !NM; g B
f (t) =
P∞
n=1
pn fn (t)
1
2
n
n
< : ø>
Sν =
ν P
ξk =
∞ P
Sn I(ν = n).
LA {ξ , n ∈ N } ; ¶ó >NO] !FÕG× i.i.d. ; DEñò : S P F (x) = P (ν = n)F (x). I JD / F (x) ; ï ð ñ ò g(t), F (x) ; ï ð ñ ò f (t), M ; n ∈ N , F (x) ; ïðñò< : ξ + · · · + ξ ; ïðñò> f (t), F (x) : 0 ;
; DEñò> g BP ; ïðñò : f (t) ≡ 1. : c @Q 5.3.6 n=0
k=1
n
ν
Sν
∞
∗n
n=0
∗n
Sν
1
n
n
∗0
0
g(t) =
∞ X
n=0
P (ν = n)f n (t).
(5.3.26)
~ FG
FG 5.3.8 I J f (t) : ïðñò>¯&RGI¡ñò `: ïðñòl
192
1◦ . g1 (t) =
1 2−f (t) ;
2◦ . g2 (t) = eλ(f (t)−1) ,
Æ l
F 1 .
¢&=
λ > 0.
◦
g1 (t) =
cG
1 2
∞ P
= 1,
F
n=0
2◦ .
1 2n
g B
∞ 1 1X 1 n = f (t), 2 − f (t) 2 n=0 2n
: ïðñò ;&B º > g B C : ïðñò!
g1 (t)
g2 (t) = eλ(f (t)−1) = e−λ
∞ X λn n f (t), n! n=0
: ïðñò ;&B º > g B `: ïðñò! ¾@ 8 >ôcTS 5.3.4 A > g (t) g (t) M : ¶ó S ; ïðñò> 1 = ν ÂÃ ?DE G( ); 2 = ν ÂÃ Poisson DE P (λ). §5.3.4 UVWXYZ' c @?I 5.3.1 B?[ ¢?\ Ò ; É?9?> ø lï ð ñ ò f (t) A B c]D?E ñ ò 4_ @ ! ®`,É9a, ; > DEñò F (x) : ` AB F (x) g^ c ¢ ïðñò f (t) g^ 4_ @ eb ì >Nc3 ; DEñò A 3d ; ïð ñ òe S&RT_=&TlfDEñò ïðñò UV ^ 4=_ @ ! eb ì >fc3 ; D Eñò4 @ c3 ; ïðñò! a> `,¯RGïðñò f (t) ; ag ! *,¯&RG45Dh½J! Î 5.3.2 F cG
e−λ
∞ P
n=0
λn n!
= 1,
g B
g2 (t)
1
1 2
◦
lim
x→∞
¢&=
©ª lk/
sgn{a}
:
a
Z
;ij ñò!
2
ν
◦
x 0
π sin au du = sgn{a}, u 2
Rx
(5.3.27)
l D me y = au, Únoñò : )ñduò>, lim I(a, x) = lim sgn{a}I(1, x). Bg ö¯&R I(a, x) =
x→∞
0
sin au u
x→∞
lim I(1, x) = lim
x→∞
x→∞
sin u u du
=
π 2.
FG
§5.3
S
m.
193
I(1, x), p eDqL>
1 u
=
R∞ 0
e−uv dv
Z ∞ Z x Z ∞ Z x I(1, x) = sin u e−uv dv du = e−uv sin udu dv 0 0 0 0 Z ∞ 1 v sin x + cos x −vx = − e dv 1 + v2 1 + v2 0 Z ∞ π s sin x + x cos x −s e ds. = − 2 x2 + s 2 0
\b4>_5 DDà= ; o - ñ ò¯o se! g þ ÿ >r c Lebesqe þ ÿ@Q > A W x → ∞ 0. Q IJ f (t) : c (5.3.3) g@I ; ïðñò>^>? ' M5.3.7 (UVWX ) F a, b ∈ R, −s
1 F (b) + F (b + 0) F (a) + F (a + 0) − = lim c→∞ 2π 2 2
©ª l¿W
a=b
b> 8 9ßM
0,
Z
t A cu2
c −c
e−ita − e−itb f (t)dt. (5.3.28) it a < b.
ûvD
Z c −ita 1 e − e−itb f (t)dt 2π −c it Z c Z ∞ −ita 1 e − e−itb itx = e dF (x) dt. 2π −c it −∞
J(c) :=
cG g B D
cG- Q
J(c)
5.3.2
−ita e − e−itb itx |eit(b−a) − 1| e = ≤b−a , it |t|
Fw> Y AB p eDqL> t F
Z ∞ Z c −ita 1 e − e−itb itx J(c) = e dt dF (x) 2π −∞ it −c Z ∞ Z c Z c 1 sin t(x − a) sin t(x − b) = dt − dt dF (x) π −∞ t t 0 0 Z ∞ 1 = (I(x − a, c) − I(x − b, c)) dF (x). π −∞
1, a < x < b, 1 −2, x = a, 1 lim (I(x − a, c) − I(x − b, c)) = 1 c→∞ π x = b, 2, 0, x < a, x > b.
~FG
FG g B +4+Ï x ¶+·ô³ >; c, _+ñ+òxFxy+!++S J(c) D+ 5 vzDx> Yx{ Lebesque þÿ@Q 194
lim J(c) =
c→∞
Z
=
0dF (x) + (−∞,a)
Z
{a}
1 dF (x) + 2
Z
1dF (x) + (a,b)
F (b) + F (b + 0) F (a) + F (a + 0) − . 2 2
Z
{b}
' 5.3.8 (Z' ) DEñòFcGïðñò ^ 4_ @ ! ©ª ¿l SDEñò F (x) ; rs,/ C(F ), 2 f (t) W a, b ∈ C(F ) b>Nag (5.3.28) | Z
1 c→∞ 2π
F (b) − F (a) = lim
c
1 dF (x) + 2
F (x)
Z
0dF (x) (b,∞)
; ïðñò!
e−ita − e−itb f (t)dt. it
* : a } C(F ) = à −∞, F (x) } > ? x = b ∈ C(F ) ~ o f (t) g?^ 4?_ b> A : b } C(F ) =T8 à x, c F (x) ; rs> ) @ !W x 6∈>C(F ? x ∈ R ~ oM f (t) ^ 4_ @ ! F (x) } 5.3.1 S @Q 5.3.8
ïðñò ; @I U ½ º > A lDEñò
ïð ñò UV ^ 4_ @ ! ' 5.3.9 IJïðñò f (t) A > ^ ; DEñò
Z
F (x)
∞
a ∈ R,
|f (t)|dt < ∞,
rsp>Y ¢ tuñò −∞
p(x) =
©ª l¿>°
−c
:
1 2π
Z
bn ∈ C(F )
F (b ) − t B cGêë ¾ (5.3.29) g 8» @3&R F (a) = F (a + 0), >° x ∈ R, ∆x 6= 0, cTag F (bn ) − n
∞
f (t)e−itx dt.
−∞
Y
bn ↓ a,
R∞
≤
(5.3.30)
F R∞
|f (t)|dt, c T 4 Ø¡ ↓ 0, rs F (x) ~~
F (a)+F (a+0) 2 F (a)+F (a+0) 2
(5.3.29)
bn −a 2π
−∞
F (bn ) ↓ F (a + 0),
4 Ò> 8 = ; oñòo A ; ñò |f (t)| gþÿ > Ó 4ÒW ∆x → 0 b> oñòà e f (t), t c Lebesque þÿ@Q ¯ (5.3.30) F (x+∆x)−F (x) ∆x
=
1 2π
−∞
e−itx −e−it(x+∆x) f (t)dt, it∆x
−itx
ÖÕf×!> ïðñò : JK9 ; F ¡ÒZ<95Ò± ; H2 §5.3.5
FG 195 1. *,x4Y¡É9 ] DE¢ ] ;£¤ ¥ ( 5.3.3 ]¦§ |¨ ξ : ] ; >IJ ξ
−ξ 3DE]45DEñò ] ; >IJ P :© 5 ] ; ¦§ |¨ ξ ; DEñò>Nª F (x) : §5.3
1 − F (x + 0) = F (−x),
∀ x ∈ R.
(5.3.31)
¥ 5.3.10 DEñò F (x) : ] ; ²D«`êë : P ; ï ðñò 0ñò ©ª ¿l IJDEñò F (x) : ] ; >NM;Fc (5.3.31) ¬
f (t)
@
R∞
sin txdF (x) = 0, ∀ t ∈ R, à R f (t) = cos txdF (x), ∀ t ∈ R @ 0 ñ ò N a > I J ï ð ñ ò @0ñòÇ2 P : ¦§ |¨ :ñò>NM;<F ì f (t) −∞
∞ −∞
ξ
; ïð
<!&R ξ
−ξEeF U =3 f; (t)ï=ðfñ(−t)ò> =éf a(−t)F U = 3 Ee; DE= ñEeò>ª, ξ ; D Eñò ] ; F (x) : 5.3.9 c (5.3.25) g@I ; ]¦§ |¨ ξe = ξ − η : ] ; Æ lfcG9 5.3.4 ; ¯&RT ξe ; ïðñò : |f (t)| @0ñò −itξ
itξ
it(−ξ)
2
2 ξ
®ξ ¯°¦ § |¨ > P ; DEñòD± F (x) ¢ F (x), P ; ïðñ òD± f (t) ¢ f (t). FÕG× ø>mIJ ξ
ξ UV² ¬ >³M; ξ + ξ ; D Eñò F (x)
F (x) ;´ F ∗ F (x), ξ + ξ ; ïðñò f (t)
f (t) ;µ f (t) · f (t). ¶· z{ µ `&¸Gz{ ´ ij ¹ > ïðñò
DEñò UV ^ 4_ @ éaº } ² ¬ ¦§ |¨ì ¢ ; DEb> ¹B ïðñò D ?¼» × l ? D?E ñ ò ;?´ ¯¼R] 4 |?D?E ; ?½??I J ® } à ïðñò ;¾ u¿d>NMÀ | £¤Á ¶ Âà O 5.3.10 ÄÅ®¯° l¿IJ¦§ |¨ ξ
ξ UV² ¬ >TD± Âà ¨ îDE N (a , σ ), j = 1, 2, ^ ξ + ξ Âà ¨îDE N (a + a , σ + σ ). Æ lÆx øx¦x§ |x¨ ξ Â+à ¨+îxDxE N (a, σ ) W+Y+Z+W ξ ; ï+ð+ñ+òx éôaÇ>IôJǦǧ |Ǩ ξ
ξ UôVDz ¬ >NDDZ Âôà ¨ôîÇDÇE f (t) = e . ^ ξ + ξ ; ïðñò N (a , σ ), j = 1, 2, 2.
1
2
1
1
2
1
1
1
2
1
2
2
2
1
1
2
1
2
1
j
2 j
1
2
2
1
2
2 1
2 2
2
2 2 iat− σ 2t
j
2 j
1
1
2
2
σ 2 t2 f (t) = f1 (t) · f2 (t) = exp ia1 t − 1 2
σ 2 t2 exp ia2 t − 2 2
2
2
~FG
FG
196
(σ 2 + σ22 )t2 = exp i(a1 + a2 )t − 1 2
,
 à ¨îDE N (a + a , σ + σ ). 5.3.11 Poisson ®¯° l¿IJ¦§ |¨ ξ
ξ UV² ¬ >]D±  à Poisson DE P (λ ) ¢ P (λ ), ^ ξ + ξ Âà Poisson DE P (λ + λ ). Æ lGcT¦§ |¨ ξ Âà Poisson DE P (λ) WYZW ξ ; ïðñò f (t) = é a?>I J?¦?§ ¬ >ND?±  à Poisson D?E exp λ(e ) . ? | ¨ ξ
ξ U V?² ¢ P (λ ), ^ ξ + ξ ; ïðñò P (λ ) g B
ξ1 + ξ 2
1
2 1
2
2 2
1
1
2
1
2
itx−1
1
1
1
2
1
2
2
2
2
f (t) = f1 (t) · f2 (t) = exp λ1 (eitx−1 ) exp λ2 (eitx−1 ) = exp (λ1 + λ2 )(eitx−1 ) ,
g B ξ + ξ Âà Poisson DE P (λ + λ ). 5.3.12 ÈÉ®¯° l¿IJ¦§ |¨ ξ
ξ UV² ¬ >TD± ÂÃÛ < DE B(n; p) ¢ B(m; p), ^ ξ + ξ ÂÃÛ< DE B(n + m; p). Æ l c]?¦?§ |?¨ ξ  à Û?< D?E B(k; p) W Y Z W ξ ; ï ð ñ ò? f (t) = éa> IJ¦§ |¨ ξ
ξ UV² ¬ >]D± Â ÃÛ< DE B(n; p) ¢ (q + pe ) . ^ ; ïðñò 1
2
1
2
1
1
it k
g B
2
1
B(m; p),
2
ξ 1 + ξ2
f (t) = f1 (t) · f2 (t) = (q + peit )n · (q + peit )m = (q + peit )n+m ,
ÂÃÛ< DE B(n + m; p). §5.3.6 ÊËÌÍÎÏ S n Ð DEñò F (x , · · · , x ) ; ïðñò @I ξ1 + ξ 2
1
IJ
2
f (t1 , · · · , tn ) =
n
\¦§FE ¨
Z
∞ −∞
ξ1 , · · · , ξn
···
n
Z
∞
(
exp i
−∞
n X
t k xk
;Ѻ DEñò :
k=1
(
f (t1 , · · · , tn ) = E exp i
n X
)
dF (x1 , · · · , xn ).
F (x1 , · · · , xn ), ) tk ξ k
(5.3.32)
^F
,
(5.3.33)
abS f (t , · · · , t ) ] n \¦§FE ¨ ξ , · · · , ξ ;Ѻ ïðñò j >NÒÓFc ξ , · · · , ξ ;Ѻ ï ð ñò f (t , · · · , t ) Å P ;ÔÕÖ× ïð ñòNØÙ ξ ; (Ö× ) ïðñò Á : 1
n
k=1
1
1
n
n
1
n
1
f1 (t) = f (t, 0, · · · , 0) =
Z
∞ −∞
···
Z
∞ −∞
exp {itx1 } dF (x1 , · · · , xn ).
§5.3
FG ¶· f (t , · · · , t ) : 1
n
à fF (t , · · · , t ) } ∞, è 1
n
Rn
n
n
(x1 , · · · , xn )
;ÜÝ ñò>NFÙ¡Þß
|f (t1 , · · · , tn )| ≤ f (0, · · · , 0) = 1;
áâ ¦ãäæåÙç  ÐÑ ò
Eξ1k1 · · · ξnkn = i
ÐÚ&ÛT¨
f (−t1 , · · · , −tn ) = f (t1 , · · · , tn );
−
n P
kj
j=1
∂ k1 +···+kn f (t1 , · · · , tn ) ∂tk11 · · · ∂tknn t
Ð ïðñò>NéFêë ; agìí
k1 , · · · , kn ,
F
197
E ξ1k1 · · · ξnkn <
.
(5.3.34)
1 =0,···,tn =0
P (a1 ≤ ξ1 ≤ b1 , · · · , an ≤ ξn ≤ bn ) Z c1 Z c1 Y n e−itj aj − eitj bj 1 = lim · · · f (t1 , · · · , tn )dt1 · · · dtn . cj →∞, j=1,···,n (2π)n −c itj −c1 j=1 1
îï ð ;ñò >Nc#¯&RTß ¥ 5.3.11 ¦§ |¨ ξ
η óô ² ¬ N> õ à ö õ Eei(t1 ξ+t2 η) = Eeit1 ξ Eeit2 η ,
∀ t1 , t2 ∈ R.
(5.3.35)
©ª ß ¾ Ú á >÷õ¦§ |¨ ξ
η óô ² ¬ø > ¶· F (5.3.35) íÔ ¬ ÷a ì > õ (5.3.35) íÔ ¬ø >Tc# ï agìí¯&RT¦§ ÛT¨ (ξ, η) ;Ѻ DEµ P ; Ö× DE ;µù &»G× }@Q 5.3.5 = ¯&R æ ßNõ¦§ |¨ ξ
ξ óô ² ¬ø >NF 1
2
¾ Ú á N> ú½9 ; : cÔ ¬ ; Nû ( ÒÓe"fü ý Ò ; aØ∀ß t ∈ R. þ 5.3.13 ÿ ¦§ TÛ ¨ (ξ , ξ ) ;Ñ Ee
it(ξ1 +ξ2 )
= fξ1 +ξ2 (t) = fξ1 (t)fξ2 (t) = Ee
1
p(x, y) =
¶·
ξ1
ξ2
itξ1
Eeitξ2 ,
2
1 + xy(x2 + y 2 ) , 4
c óô ² ¬ > : F
|x| ≤ 1, |y| ≤ 1.
fξ1 +ξ2 (t) = fξ1 (t)fξ2 (t).
H 5.3 1. Pascal f (k; r, p) 2. Γ(λ, r) k 3. F (x) !" # f (t), $%!&' x, () R 1 c→+∞ 2c
F (x + 0) − F (x) = lim
4.
c
*+,-./0 123" 45 6 (1) cos2 t,
(2) cos t − i sin t,
1−t (3) 1+t 2,
(4) sin t,
−c
mk .
f (t)e−itx dt.
1 (5) 1+it ,
(6) 2e−it − 1
−1
.
789;:=>@A>@=B?:
198 g(u) = 1 − |u|, |u| < 1.
5.
C g(x) #DE F (2) GHIJC g(t) # DE 6. Laplace DE# p(x) = e , $K ˙ 7. LNM Cauchy N N NDNENNN# p(x) = , λ > 0, $N%NON N NNNN# e , PQRST%U Cauchy VWX 8. YZ[\] ξ ^_ Cauchy µ = 0, λ = 1, ` η = ξ, $%ab cde f (t) = f (t)f˙ (t). f 0 ξ g η hid 9. ξ , · · · , ξ #3jid Zk[k\k]klk^k_ Cauchy m µ = 0, λ = 1, ξ¯ = P ξ 10. $n g Γ− %U!bo)3kl λ p Γ− abq r )VWX 11. %UZ[\] ξ , · · · , ξ 3jid r stuv0Ow xy zb{}|~ 12. −1 < c < 1, Z[\] (ξ, η) xyDE# P (x, y) = [1 + cxy(x − y )], |x| < 1 m |y| < 1, $6 (1) xy f (s, t); (2) ~ f (s) g f (t); (3) ξ + η 13. %U!&'p f (t), C,
hzJcd 1 − f (2t) ≤ 4(1 − f (t)); 1 + f (2t) ≥ 2(f (t)) . 14. Z[\] ξ o)! 45DE!&' x ∈ R, () p(x) = p(−x). $6 !&' a > b )6 R (1)
1 −|x| 2
1 λ π λ2 +(x−µ)2
iµt−λ|t|
ξ+η
1 n
1 n
η
ξ
n
k
k=1
1
n
2
1 4
2
1
2
2
(1)F (−a) = 1 − F (a) =
1 2
−
a
0
p(x)dx,
(2)P (|ξ| ≤ a) = 2F (a) − 1,
(3)P (|ξ| ≥ a) = 2[1 − F (a)].
0Z[\] ξ T f (0) = 0, ξ s 0 PQLS% U a > 2 g(t) = exp {−|t| } h0 16. % 5.3.13.
15.
00
f (t)
a
¡¢£¤¥¦§¨© ð=ª?« Û?¬ ⮯ ?Û ¬°±² §5.4
ξ1
ξ2 → − ξ = ··· , ξn
a1
a2 → − a = ··· , an
³ ³ °µ´à¶ →−0 ·¸¹&Û?¬°µº»¼ ¦ ¬½¾ 0 « ?Û ¬ ¨ ®¿ ðÀÁ ° à ÄÅÆ=Ç ¬ «ÈÉÊíß →−ξ = (ξ , ξ , · · · , ξ ), ³³ ¨ τ
1
2
n
ËÌÍ=Î?ÏÐ 199 ç âÑÒÓ A « » Ñ £Ô ½¾ÕÖ׬°Nè õØ «ÚÙÛ ½ÜÝ ø ° Ú ² ï EA ·¸Þ A « » Ñ £Ô ½ß ÙÛ °áຠEA ¾=â A « » Ñ £Ô «ãäÙÛå Æ« ÒÓ ¨ ÞæÕÖ Ç ¬àçèé «êë ¨ Þæì £¤¥ ° =í?îïðñòó ã ¨ô Ý Å →−a = (a , a ) , §5.4
1
B=
õö
σ12
rσ1 σ2
rσ1 σ2
σ22
!
2
τ
,
Ç ¬ →−ξ «ãäÙÛ=Ç ¬÷ B ¾ Ø«øùú Ó ¨ò ª B ¾û Ñ ¾ ì ¼ Õ Ö ¤ ë ÒÚÓ °´ÚüÚì £Ú¤Ú¥ÚÚÚó ãýªþ«ÚÿÚã ½ÚÝ ØÚ«ÚãÚäÚÙÚÛýÇ ¬ ø ù ú Ó B ª ¨ ° B ÒÓ → − a
B −1 =
°¶ Ø ì £¤¥ − p(→ x)=
ò ª |B| ¾ ÒÓ ¢£ ¨
B
−r (1−r 2 )σ1 σ2 1 (1−r 2 )σ22
1 (1−r 2 )σ12 −r (1−r 2 )σ1 σ2
N (a1 , a2 ; σ12 , σ22 ; r)
.
« ó ãÅ ®
1 → τ −1 → − → − − → − ( x − a ) B ( x − a ) , exp − 1 2 2π|B| 2 1
« ¯ ¨ ì £¤¥ ó ã« ·¸ Ê ¶ ù
! " # $ % '&'(')'*'+ «','- . ¨0/'1 ξ , ξ , · · · , ξ ¾ 'ë 2 Ý è û'3'4'5'6 « 7 8 9 : « ¤¥ N (0, 1) ÕÖ׬° õö n ¼ ÕÖ Ç ¬ →−ξ = (ξ , ξ , · · · , ξ ) « ; < = ¾ n Ñ û¼ ¤¥ <« > ? °º §5.4.1
n
1
2
n
1
@ A °B C
− p(→ x)=
1 1 − x21 + x22 + · · · + x2n , n exp 2 (2π) 2
→ − → − E ξ = 0,
øùú Ó®
´ü ¶ D < ó ãÅ ® − p(→ x)=
1
0
···
0
0 1 ··· 0 I= ··· ··· ··· ··· 0 0 ··· 1
n
£¤¥¦§ °Iç
n
τ
− → x ∈ Rn .
,
1 1→ 1 1→ τ→ τ → − − − − exp − x x = exp − x I x , n n 2 2 (2π) 2 (2π) 2
D E ¦ § F ® G H û J °
2
→ − N ( 0 , I).
→ − x ∈ Rn . (5.4.1)
789;:=>@A>@=B?: K L 5.4.1 ² M A ® n × n N O ù Ó ° →−a ® n ¼ Ç ¬°QPÕÖ Ç ¬ →−ξ R ( G H n £¤¥¦§ N (→−0 , I), S D 200
→ − − → − η =Aξ +→ a
« ¦§ F ® n £¤¥¦§¨ @ T ° Þæ² ë 2« P →−η «øùú Ó®
(5.4.2)
→ − η, → − − − − E→ η = AE ξ + E → a =→ a,
→ − → − → − τ→ − − − − − B := E(→ η −→ a )(→ η −→ a )τ = E(A ξ )(A ξ )τ = AAτ · E ξ ξ = AAτ .
'U V ° AA ¾ û Ñ n W ¤ ë ù Ó ¨ D Ê ² (5.4.6) « Õ Ö Ç ¬ « ¦ § I ® n £ ¤¥ N (→−a , B), ò ª B = AA . ÿë 2« ÕÖ Ç ¬ →−η ¾ÕÖ Ç ¬ →−ξ « X Y × Z °[=â û \ ? â æ ² (5.4.6) ª?« ] A ^ °¶ : º _ `ÕÖ Ç ¬ →−η < ó ã ¨ K a 5.4.1 n £¤¥ N (→−a , B) « < ó ã ¾ τ
τ
− p(→ x)=
1 → τ −1 → − → − − → − exp − ( x − a ) B ( x − a ) . 1 n 2 (2π) 2 |B| 2 1
(5.4.3)
bdcde 1 Õ Ö Ç ¬ →−η R ( n £ ¤ ¥ N (→−a , B), S Ü ÝdR ( d G H n£ ¤ ¥ « Ç ¬ →−ξ , f ` (5.4.6) Æ : ° ò ª B = AA , P X Y ù g h → − N ( 0 , I) ÕÖ → − − − x = A→ s +→ a « i ® τ
Eã × Z « ®
Jaccobi
→ − − − s = A−1 (→ x −→ a ),
¯ ®
1
|A−1 | = |B|− 2 . − q(→ s)=
n
£¤¥
→ − N ( 0 , I)
→ − − 1 s τ→ s − , n exp 2 (2π) 2
j k ò ª ° ´ > ¶× Z « [ « D < (5.4.4) ó ã ¾
Jaccobi
¯ ° º A
n
£¤¥
τ −1 → 1 −1 → − → − − → − exp − A ( x − a ) A ( x − a ) n 1 2 (2π) 2 |B| 2 1 1 → τ −1 → − → − − → − = exp − ( x − a ) B ( x − a ) . n 1 2 (2π) 2 |B| 2
− p(→ x)=
â ë 2
â?æ G H
(5.4.4)
5.4.1
1
l @ ² mû n ¯ o p e
« < ó
− N (→ a , B)
§5.4
Ë ÌÍ=Î?ÏÐ K a 5.4.2 n £¤¥¦§
− N (→ x , B)
« q r ó ã ¾
1→ −τ → − → − → − − f ( t ) = exp i→ aτ t − t B t , 2
b c ets & °Þæ R ( G H
n
201
→ − ∀ t ∈ Rn .
£¤¥¦§ « ÕÖ Ç ¬
(5.4.5)
→ − ξ,
n 1X n τ o 1→ − → − → − → − τ→ − 2 f− tj = exp − t t , → ( t ) = E exp i t ξ = exp − ξ 2 2 j=1
( P=â ] n
(5.4.6)
º `
B = AAτ ,
n
o
n τ o → − − → − → − τ− → − f ( t ) = E exp i t → η = E exp i t Aξ +→ a n τ o n o − τ→ − → − − → − → − → − = exp i t → a · E exp i(Aτ t )τ ξ = exp i→ a t · f− → (Aτ t ) ξ − τ→ 1 − → − → − = exp i→ a t · exp − (Aτ t )τ Aτ t 2 1 → − → −τ → − − = exp i→ aτ t − t B t . 2
«u û k ¼vw ¦Ú§ ¾ k £Ú¤Ú¥Ú¦Ú§ ° ò ª 1 ≤ k < n. bce 1 ÚÕ Ö Ç ¬ →−η R ( n £Ú¤Ú¥ N (→−a , B), Þ 1 ≤ k < n, u ß 1 ≤ j < Ç ¬ (η , · · · , η ) « q r ó ã ¶ Ãñ Ý →−η « q r ó æ ¾ k ¼ÕÖ · · · < j ≤ n. ã=ªyx t = 0, t 6∈ {j , · · · , j } ` ¨ ² M I
K a
5.4.3 n
£Ú¤Ú¥
− N (→ a , B)
1
j1
k
j
j
1
jk
k
→ − tk = (tj1 , · · · , tjk )τ ,
− →k = (aj , · · · , aj )τ , a 1 k
ª?« z j , · · · , j £Ô ´¶ B ·¸=â B Ó ° õ ö (η , · · · , η ) « q r ó ã ° = ¾ k
1
j1
k
j1 , · · · , j k
¯ £Ô ÿåÆ«
k×k
{ Ò
jk
→ − f ( t ) tj =0,
tj 6∈{j1 ,···,jk }
1→ − −τ → − τ→ − → = exp iak tk − tk Bk tk , 2
âyBº A (η , · · · , η ) « ¦§ ¾ k £¤¥ N (−a→, B ). | } q r ó ã ~ ¦§ó ã« ûûÞ Y ° y (5.4.3) Å k ¼ÕÖ Ç ¬ ¤(η¥,¦· ·§· , η¨) « < ó ã ¨ âBÚ¶
n¨ £Ú¤Ú¥ « » ÚÊ « ¦Ú§ ½ ¾ çy ç ® ç K L §5.4.2 n ! " # $ % Ý ë2 5.4.1 ª Ú _ A ® NO « n × n «Úù Ó °º |A| 6= 0. ô Ý° n £¤¥¦§ «ë 2 çû ¨ j1
j1
jk
jk
k
k
y y K L 5.4.2 1 A ® u ¡ n × n ù Ó ° →−a ® n ¼ Ç ¬°QPÕÖ Ç ¬ →−ξ R ( G H n £¤¥¦§ N (→−0 , I), x 202
→ − − → − η =Aξ +→ a.
(5.4.6)
S'¢ ù Ó A« N'¦O'§ C F °£D →−η « « ¦ §'£F ¤® ¥n¦£ §¤ ¨ ¥ ¦ § ÷£¢ ù Ó A ¤'O'C (º'¢ |A| = 0 ® ¥ ¦ n C ), D →−η , § ¨ © p ¥ ¦ Ê ¨ l @ A ª °B C « E→−η = →−a , ´ü «¶ B = AA ® ø ùú Ó ° § ñ B ¾û Ñ n × n « N ¬ ë ÒÓ ¨ â?æ ë 5.4.2 «
ñ g=ª ´ ® ¯ ù Ó A « N O Y (B « ¤ ë Y ), ÿ ¶ õ °« ± « V ² ¨³ B ¥¦ « n £ ¤¥¦§ N (→−a , B) « q r ó ã èé · ´ (5.4.5). « ¾ e ¢ ÒÓ B ¤ ë (º |B| > 0) C° N (→−a , B) ¾ R ª?« û Ñ µ ¢ ¶ · ¦§ ° ò < ó ã â (5.4.3) ¨ P ¢ |B| = 0 C° N (→−a , B) ¾ R ª « µ ¶· ¦Ú§ °BC¸¹º» ÒÚÓ B « “¼ ”r (r < n). ¢ B « “¼ ” ® r CÚ° R « û Ñ r ¼ { 5 6 ª ¨ ±² e ¢ n = 1 C°² M |B| = σ = 0, − N (→ a , B) ¥ ¦ õ ö ¦ § N (a, 0) = ¾ +'½ a « ¥'¦ ¦ § ¨ Þ æ n = 2 £ ¤ ¥ ¦ § ° ²'M |B| = 0, e ² M r = 0, S¾ + ½ →−a = (a , a ) « ¥ ¦ ¦§ ÷² M S ¾ B « “¼ ”rª?« P ¿ ë ÀyX « ¥ ¦ ¦§¨ = ¾ ë2 5.4.2 ª?ÿ Á« ¥ ¦ ¤¥ r = 1, S¾ R ¦§ «  2 ¨ ° n £¤¥¦§ « u ¡ 1 ≤ k < n ¼ « v w ¦§ ½¾ ¥ ¦ « n £¤¥ ¦ § ° ³ ® Þ æ k ¼'{ Õ Ö Ç ¬ (η , · · · , η ) Á ° ²'M'D Ø « «'q'r ó ã « · ´ ª?« k W ¤ ëù Ó B à ² m ù Ä Å® û Ñ n W N ¬ ëù Ó B: B « » Æ Ç ç ® B « z j , · · · , j ° B « » ¯ Æ Ç ç ® B « z j , · · · , j ¯ °È D= ò É£Å Ô Ê Ë Ì Å«® Ê 0, Þ¨ Ç ¬ →−a àçèé Í ° õö (η , · · · , η ) « q r ó ã ¶ ® (5.4.5) Î Ï §5.4.3 n ! " # $ % 1 ÕÖ Ç ¬ →−ξ R ( n £¤¥¦§ N (→−a , B). K a 5.4.4 n ¼ ¤¥ Ç ¬ « » Ñ ¦ ¬ 7 8 9 : °¢ü Ð ¢ Ø Ñ Ñ 7 ] ¨ b'c'e ²'M n ¼ ¤ ¥ Ç ¬ →−ξ « » Ñ ¦ ¬ ξ , · · · , ξ 7 8'9': ° õ ö Ø ¢ V Ñ Ñ 7 ] ¨ Ò°µ² M ξ , · · · , ξ Ñ Ñ 7 ] ° õö = Cov (ξ , ξ ) = b , k 6= j, æ¾ →−ξ «øùú Ó B ¾Þ Ó Ó ° ( P (5.4.5) ª?« q r ó ã ¦® τ
n
n
n
2
1
2
2
j1
jk
k
k
1
k
k
1
j1
1
1
f (t1 , · · · , tn ) =
k
k
1
n
j
kj
Y n 1 exp iak tk − bkk t2k = fk (tk ), 2
âó ãë ÿ 5.4.3 ª?« ) Ô û Ñ Õ Ö 7 A 8 f 9 (t: ) ¨ = exp ia t ° ¶ · ξ , · · · , ξ k=1
jk
n
n
n Y
k
k
k k
k=1
− 21 bkk t2k
¾
ξk
« v w q r
§5.4
Ë ÌÍ=Î?ÏÐ K a 5.4.5 Þæ
n
¼ ¤¥ Ç ¬
→ − ξ
« u û ¦ × → − ! ξ1 , → − ξ2
→ − ξ =
¶Þ
→ − a
B
ç 7 « ¦ × → − a1 → − a2
→ − a =
!
,
203
B=
B11
B12
B21
B22
!
.
(5.4.7)
´ ü →−ξ ~ →−ξ 9 : « Å ¦ ¸ ¾ B = 0 ( B Cà B = 0). b c e ¶Þ →−a B ç 7 « ¦ × (5.4.7) ¾ U V « ¨ ² M →−ξ ~ →−ξ 9 : ° õ ö Ø « u ¡ û Ñ ¦ ¬ ξ ½ ~ Ô « u ¡ û Ñ ¦ ¬ ξ 9 : ° ( P b = b = 0, ³ → − → − → − ξ = ξ , ξ æ ¾ B = 0 B = 0. Ò°² M B = 0( P B = 0), S « ; q r ó ã ® 1
2
12
21
1
k
12
j
21
12
2
kj
jk
1
21
τ
2
n τ o − → − → − → − → − τ→ f ( t ) = E exp i t1 ξ1 + t2 ξ2 1→ 1→ − −τ → − − −τ → − τ→ τ→ → − → − = exp ia1 t1 − t1 B11 t1 · exp ia2 t2 − t2 B22 t2 , 2 2
Ù Ú ¾ →−ξ ~ →−ξ « v w q r ó ã « > ? ¤¥ ÕÖ Ç ¬ « ¡ ª ° î Ä Ý Þ ( n £¤¥¦§ N (→−a , B), P C = (c 1
2
° ÿ ¶ →−ξ ~ →−ξ 7 ¨ º » Ø« X Y ) ® m × n ÒÓ 1
jk
2
8 9 : ¨ × ò Z ª¨y1 ÕÖ Ç õ¬ ö ° m ≤ n,
→ − → − η =Cξ,
R
→ − ξ
(5.4.8)
= ¾ →−ξ « û Ñ X Y × Z ¨ U V ° →−η ¾û Ñ m ¼ « ÕÖ Ç ¬ ¨ â n £¤¥¦§ « q r ó ã l @ ` ² m o p ¨ K a 5.4.6 (" # $ % Û Ü Î Ý Þ ß à á â Ý ) (5.4.8) ª?« ÕÖ Ç ¬ →−η R ( £¤¥¦§ N (C →−a , CBC ). m b c e ¶ f (→−t ) ·¸ →−ξ « q r ó ã ° õö →−η « q r ó ã ® τ
n o n o → − − τ → − − − − − g(→ s ) = E exp {i→ s τ→ η } = E exp i→ s τ C ξ = E exp i (C τ → s) ξ 1− τ τ − − − − s (CBC τ ) → s , = f (C τ → s ) = exp i (C → a) → s − → 2
¤ ¾ m £¤¥¦§ N (C →−a , CBC ) « q r ó ã ¨ ¶ m « Ñ Ñ p Þæ ¡ n £¤¥¦§ ã¦ ä ¨ å 5.4.1 ² MÕÖ Ç ¬ →−ξ R ( n £¤¥¦§ N (→−a , B), SÜÝ ÒÓ C, f ` →−η = C →−ξ « » Ñ ¦ ¬ 7 8 9 : ¨ τ
n
¼ ¤ æ
y y b c e ³ ® Þæ u ¡ n ¼ N ¬ ë ÒÓ B, çÜÝ n ¼ ¤ æ ÒÓ C, f ` CBC ® Þ Ó Ó ¨ å 5.4.2 ² MÕÖ Ç ¬ →−ξ R ( n £¤¥¦§ N (→−a , B), ´ü →−ξ « » Ñ ¦ ¬ 9 : è ùú °SÞ u ¡ n ¼ ¤ æ ÒÓ C, →−η = C →−ξ « » Ñ ¦ ¬ 9 : è ùú ¨ b c e â?æ →−ξ « » Ñ ¦ ¬ 9 : è ùú °¢ÚüÐ ¢ Ø«ÚøÚùú Ó B = σ I. P Þæ u ¡ n ¼ ¤ æ ÒÓ C, CBC = Cσ IC = σ I. m è «ë é ê ¿ ë Õ û Ñ n ¼ÕÖ Ç ¬ R ( n £¤¥¦§ « ì ¨ K a 5.4.7 n ¼ Õ Ö Ç ¬ →−ξ R ( n £ ¤ ¥ ¦ § N (→−a , B), ¢ ü'Ð'¢ Þ u'¡ n ¼ Ç ¬ →−s , ½ η = →−s →−ξ R ( 1 £¤¥¦§ N (→−s →−a , →−s B→−s ). b c e Ý ë 5.4.6 ªyx C = →−s º ` ¸ Y ¨ Ò°þ² MÞ u ¡ n ¼ Ç ¬ ( 1 £¤¥¦§ N (→−s →−a , →−s B→−s ), õö η « q r ó → − → − − s , ÕÖ׬ η = → s ξ ½ R ã ® n o 204
τ
2
τ
2
τ
2
τ
τ
τ
τ
τ
ß
t = 1,
º `
τ
τ
1 −τ → → − − − − g(t) = E exp it→ s τ ξ = exp it (→ s τ→ a ) − t2 → s B− s . 2 n o 1− τ → → − − − − − E exp i→ s τ ξ = exp i (→ s τ→ a)− → s B− s := f (→ s ), 2
í · ´ (5.4.5), ÿ ¶ÕÖ Ç ¬ →−ξ R ( n £¤¥¦§ N (→−a , B). î 5.4.1 ¢ ° ë 5.4.7 ï ð e n ¼ÕÖ Ç ¬ →−ξ R ( n £¤¥¦ § °y¢ü Ð ¢ Ø« » Ñ ¦ ¬ ξ , · · · , ξ « u X Y h R ( 1 £¤¥¦§¨ ñ ò ó e ² M n ¼ÕÖ Ç ¬ →−ξ « » Ñ ¦ ¬ ξ , · · · , ξ ½ R ( 1 £¤¥¦§ ° = ¶ ô
→−ξ R ( n £¤¥¦§ ° ±² m e õ 5.4.1 1 ò ª
− f (→ s)
1
n
1
p(x, y) =
1 −1 1 − x2 +y2 2 + e e 2 I (|x| < 1, |y| < 1, xy > 0) 2π 2π 1 1 − e− 2 I (|x| < 1, |y| < 1, xy < 0) , (x, y) ∈ R2 . 2π
¤ ¥e ¦p(x,§ y) ¾ ¿ Ñ ÕÖ Ç ¬ H N (0, 1). b c e I q(x, y) =
S @ T e ¢
n
(ξ, η)
« < ó ã °?´üÕÖ׬
ξ
~
η
(5.4.9)
½ R ( G
1 −1 1 −1 e 2 I (|x| < 1, |y| < 1, xy > 0) − e 2 I (|x| < 1, |y| < 1, xy < 0) , 2π 2π (x, y) ∈ R2 . (5.4.10)
|x| < 1, |y| < 1
C°
1
1 −2 − 2π e < q(x, y) <
1 − 12 ; 2π e
Ë ÌÍ=Î?ÏÐ Þæ ò ö « (x, y), ½ q(x, y) = 0. P ¢ ÿ ¶°Þ u ¡ (x, y) ∈ R , ½ e §5.4
1 −x 2π
205 |x| < 1, |y| < 1
2 +y2
>
2
1 − 12 . 2π e
C°
2
÷ ³ ® Þ u'¡ùø ë « y, ó ã ½¾ y « ¤ ó ã ° ÿ ¶ Z
¿ Ñ Õ Ö Ç ¬ p(x, y) ¾ −∞ −∞
Z
∞
R∞ R∞
2 +y2
« < ó ã ÷´ü=â (ξ, η)
∞
1 pη (y) = p(x, y)dx = 2π −∞
x,
ó ã
q(x, y)
∀ x ∈ R; (5.4.11)
−∞
p(x, y)dxdy =
1 pξ (x) = p(x, y)dy = 2π −∞ Z
2
Z ∞ q(x, y)dx = 0, ∀ y ∈ R; q(x, y)dy = 0, −∞ −∞ Z ∞ Z ∞ q(x, y)dxdy = 0. R∞ R∞
T
1 −x 2π e
∞
−∞
ÿ ¶
2 +y2
+ q(x, y) > 0. « ó ã ÷ Þ u'¡ùø ë « q(x, y) ½ ¾ x ¤
p(x, y) =
Z
∞
1 −x −∞ −∞ 2π e
∞
A
dxdy = 1,
(5.4.11)
x2 1 dy = √ e− 2 , 2π
∀ x ∈ R;
y2 1 dx = √ e− 2 , 2π
∀ y ∈ R.
x2 + y 2 exp − 2 −∞
Z
2
x2 + y 2 exp − 2 −∞
ÿ ¶ÕÖ׬ ξ ~ η ½ R ( G H ¤¥¦§ N (0, 1). ú ¾° â (5.4.9) A °Õ Ö Ç ¬ (ξ, η) ´ R ( 2 £¤¥¦§¨ È û Ñ ± { ¨ õ 5.4.2 1 ÕÖ׬ ξ ~ η 7 8 9 : °è R ( G H ¤¥¦§ N (0, 1), x ζ=
S
ζ
û R ( G H ¤¥¦§ ü e â ζ « ë 2 °`
(
N (0, 1),
|η|,
ξ ≥ 0,
(5.4.12)
−|η|, ξ < 0.
ú ¾ÕÖ Ç ¬
(η, ζ)
R (
2
£¤¥¦§¨
P (ζ < x) = P (ζ < x, ξ ≥ 0) + P (ζ < x, ξ < 0) = P (|η| < x, ξ ≥ 0) + P (−|η| < x, ξ < 0)
[ ¢
x≥0
C°
= P (|η| < x)P (ξ ≥ 0) + P (−|η| < x)P (ξ < 0). Z x u2 1 1 1 1 1 P (ζ < x) = P (|η| < x) + = √ e− 2 du + 2 2 2 2π −x 2 Z x Z x 1 u2 1 1 u2 =√ e− 2 du + = √ e− 2 du = Φ(x); 2 2π 0 2π −∞
y y
206
¢
C°
x<0
< x) = (P (η < x) + P (η > −x)) = P (η < x) = Φ(x). ÿ ¶PÕ(ζÖ<×x)¬ =ζ R P( (−|η| G H ¤¥¦§ N (0, 1). ú ¾ 1 2
1 2
P (η + ζ = 0) = P (η + ζ = 0, ξ ≥ 0) + P (η + ζ = 0, ξ < 0) = P (η + |η| = 0, ξ ≥ 0) + P (η − |η| = 0, ξ < 0)
= P (η + |η| = 0)P (ξ ≥ 0) + P (η − |η| = 0)P (ξ < 0)
= P (η ≤ 0)P (ξ ≥ 0) + P (η ≥ 0)P (ξ < 0) = , T
â( yB £¤¥η +¦ζ§¨ R ( 1 £¤¥¦§ ° ÿ ¶=â ë 5.4.7 A °ÕÖ Ç ¬ (η, ζ) R 2 Ý Ç ± ª ° â « æ ; Õ Ö ×< ¬ ξ ~ Ø η 7 « 8'9': °<è'« R >( ? G'H ¤¥¦ § N( (0, 1),£¤ÿ ¶¥ Õ ¦Ö§¨ý ¬ þ (ξ,°η) ¶
?ÕÖ Ç Þ¬ æ (ξ, ζ) v R w ( 2 £¤¥¦°§[ ¨ (ξ, η) R 2 ) Ô ° û Ñ ë 5.4.6 « ± { ¨ õ 5.4.3 1 ξ , ξ , ξ ® 7 8 9 : « N (a, σ ) ÕÖ׬°P ÿ _ D(η η ). η = (ξ + ξ + ξ ) , η = (ξ − ξ ) . ü e I →−ξ = (ξ , ξ , ξ ) , S →−ξ R ( 3 £¤¥ ° ò ÙÛ øùú Ó ¦ ® 1 2
1
2
2
3
√1 3
1
1
2
3
√1 2
2
1
2
1 2
1
È I S
→ − η = (η1 , η2 )τ ,
→ − → − η =Cξ,
3
→ − a = (a, a, a)τ ,
³ B=â ë
τ
C= 5.4.6
a − C→ a =C a = a
7 8 9 : °´ ü N (0, σ ). y â B @ ` ÿ ¶
η1
~
2
η2
√1 3 √1 2
A
→ − η
√
3a
0 η1
√1 3 − √12
R (
!
B = σ 2 I.
,
2
√1 3
0
£¤¥
!
, − N (C → a , CBC τ ).
τ
CBC =
R ( ¤ ¥ ¦ §
σ2
0
0
σ2
!
â?æ
= σ 2 I,
√ N ( 3a, σ 2 ), η2
R ( ¤ ¥ ¦ §
2
D(η1 η2 ) = E(η12 η22 ) − (Eη1 Eη2 )2 = Eη12 Eη22 = Dη1 + (Eη1 )2 Dη2 = σ 2 + 3a2 σ 2 .
5.4 1. (ξ, η) 2 ! ~a =
0 1
,
B=
4
3
3
9
!
.
!"$#%& 207 '()* (1) +,-./01 (2) +,23/04 '78 ξ + η ξ − η 9:;< *=>?@ 4 2. 5 (ξ, η) 6 *AB 4CDEFGHI0 b , b , · · · , b , JK 3. 5 ξ~ = (ξ , · · · , ξ ) n P (b ξ + · · · + b ξ = b ) = 0 L 1. N * N A B ON QPNF k, j = 1, 2 K E(ξ ) = 0 E(ξ ξ ) = σ > 0. 4. (ξ , ξ ) M 2 N N NN ( η = ξ ξ * -./04 '(R 5.4.2 S AB T (ζ, ξ) * UCD )V 2 4 5. * ABW '( aξ + bη cξ + dη * 9XY0 6. ξ η 9:;< Z S σ > 0 P ab 6= 0, cdN6=(0,0.σ ) ABW ξ , · · · , ξ 9:;< J[\ ' F m < n ( 7. X η = ξ η = Xξ * +, 4 *ABW Z -.^/0 V^_` 0 PK6ab0 ' C5 8. ξ η M9:;<9] ABW ξ, η, ξ + η, ξ − η d 4 ξ + η ξ − η 9:;< c ABW ξ , · · · , ξ 9:;< J N (0, σ ) 4e ξ = P ξ . (1) '( ξ * 9. 1 (2) ( ξ ξ * 9XY04
§5.5
1
n
τ
0
1 1
1
n n
1
n
0
2
2
k j
k
1 σ2 1 2
2
2
1
n
n
m
1
2
k
k
k=1
1
k=1
2
n
1 n
n
k
k=1
1
fhghikjmlhnhohphq rstu$vwxyz{| χ yz} t yz~ F yz}
v vwxyzrs Õ u$ ä §5.5.1 χ $ ¡w¢¡ 6 £ u$¤¥¦ χ yzv§¨}©ª{« χ yz¬ Γ yz Γ(λ, r) v®¯°±v³²«´ λ = , r = v Γ yzµ “ ¶$·$¸ n v yz ”. ¹ º»¼½¾¿ χ yz χ yzÀrsu$Á χ ¨}{ ¹Ã rstvÄÅÆǼv K. Person ÈÉ ºv}{rstu$v¼ÊËÌ vÍÎyz ÏÏÀÏrÏsÐuÑ« ¶Ñ·Ñ¸ n v χ yÏzÏÒϬÏÒÏ χ , Ó «ÏÔÏÕ ¸ ÏÏÒÏ ° É }ØÙ Γ yzvÕ ¸ (´Ú (3.6.4) Û ) u$Ü λ = , r = , k (x). Ö× ²ÝÞßà §5.5
2
2
2
2
1 2
2
n 2 2
2
2
2 n
1 2
n
kn (x) =
1 n Γ( n2 )2 2
x
e− 2 x
n−2 2
,
x>0,
n 2
(5.5.1)
Ôu$¼Ê´ n ∈ N . áâã K. Person väå}Æ«yz χ µ “ ¶$·$¸ n v Person χ yz ”. Øæv§Àçè$à χ yz n Ê
v véê~}ë{ “ ¶$·$¸ n” vì¨í 2 n
2
2 n
208
øù
Ü ý
5.5.1
ú
v yzþ{ χ . η ÿ à¡w¢¯
ξ 1 , ξ2 , · · · , ξn
î ïðòñó$ôõöôõ÷$ñ
}ûüyz N (0, 1),
η = ξ12 + ξ22 + · · · + ξn2 ,
2 n
vÕ ¸ { k (x) = exp − , x > 0 . ú ¿ n = m }º ·° Γ( ) = √π,Õ í (5.5.1) Û n=1 n = m + 1. · ¸ v Û 3.7.5
u$}$ Þ √1 2πx
1
η = ξ12
x 2
1 2
Z
Z x km (u)k1 (x − u)du = km (u)k1 (x − u)du −∞ 0 Z x m−2 1 1 −x 2 e u 2 (x − u)− 2 du. = m 1 m 1 Γ( 2 )2 2 · Γ( 2 )2 2 0
km+1 (x) =
yu$¬ Z
∞
u = xt,
(5.5.2)
Þß
Z 1 m−1 m−2 1 1 (x − u)− 2 du = x 2 t 2 (1 − t)− 2 dt 0 0 m 1 m−1 Γ( m−1 m 1 2 )Γ( 2 ) , =x 2 B , =x 2 m+1 2 2 Γ( 2 ) x
u
m−2 2
Ù Ã ¥ (5.5.2) Û }² (5.5.1) Û n = m + 1 Øæv§Àá χ yzv à øù 5.5.2 ØÙ η η
}Ôu η ûüyz χ , η ûü yz χ , ý η + η ûüyz χ . ÿ àÏÏÝÏÏÕ ¸ ÏÏv Û èÑÇÏ}ëÏÝÏϧÏÀ 5.5.1 Þ É ¿ }Ü ØÙ n + m Ê
ûü yz v ξ ,ξ ,···,ξ , 2
1
2 m
1
ý
1
2
η1
2
1
2 n
2
2 n+m
2
n+m
η2
} Ó
η1 = ξ12 + · · · + ξn2 , η1 ∼ χ2n ,
2 2 η1 = ξn+1 + · · · + ξn+m ,
η2 ∼ χ2m ,
!
í · §À 5.5.1 η + η ∼η χ+ η =. + · · · + ξ , ¯ 4.4.2 $ " à$#%Ê´v|yzv { Γ yz}Øæ · v § À ý » ¼ ½'&' á χ y z û ü ' ´ v | y zv Ç~v yzv( øù 5.5.3 Ø Ù ξ , ξ , · · · , ξ
} û ü ´ λ > 0 v | yz}ý 1
1
2
2
ξ12
2 n+m
2 n+m
2
1
2
n
η = 2λ(ξ1 + ξ2 + · · · + ξn ) ∼ χ22n .
§5.5
) *,+-./012 ÿ à · ¯ 4.4.2 u$v
Û }
4.4.7
!
í
vÕ ¸ 3 η
vÕ ¸ {à
ξ 1 + ξ2 + · · · + ξ n
λn n−1 −λx e , Γ(n) x
pn (x) =
x>0.
Fη (x) = P ξ1 + ξ2 + · · · + ξn <
x 2λ
,
x x d 1 1 λn x n−1 − x 1 Fη (x) = pn = e 2 = e− 2 xn−1 , dx 2λ 2λ 2λ Γ(n) 2λ Γ(n)2n
²
209
x>0,
k2n (x).
4 5 $è } 67 §5.5.2
t
Øæv{¼Ê89Õ ¸ à
n ∈ N,
Γ( n+1 ) tn (x) = √ 2 n nπΓ( 2 )
− n+1 2
x2 1+ n
x ∈ R.
,
(5.5.3)
«ÊÕ ¸ µ “ ¶$·$¸ n v t yz ” vÕ ¸ } ξ ∼ t ç: ξ ûü ¶$·$¸ n v t yz yz{ ·;< rst= W.Gosset 1907 >?@ AÎ Student B çv}í t Cë µ “tD,E$yz ”, ë{Àrstu$vF Á vy zÇ ¼ · ° É }HGyzvÕ ¸ IJ µ} ÔKL N (0, 1) Õ ¸ (5.5.3) Û v'K'L Ë Ì 'M N'}NO n P x'C } t y z v'Q P'R'S' yz À r s t ~ æ ¼'T £ u } U »¼ ½¾ ¿ v'VTW ªX É ¼ ʧ À} YZ t yzv[D\] øù 5.5.4 ú ÏÏÏ η η ÏÏ}ÔÐu η ∼ χ , ! η ûÏüÏÏÏÏ Ü n
1
2
2 n
1
2
N (0, 1).
ý
η2 ζ = p η1 , n
ÿ àÒ
vÕ ¸ p P (ξ < x) = P í^ Û_` x a}²Þ ξ vÕ ¸ ζ ∼ tn .
ξ=
p η1 n
,
Wº η1 n
· g (x)
ξ gn (x). R nx2 < x = P (η1 < nx2 ) = 0 kn (u)du, n
g (x) = 2nxk (nx ). b (ny ) _ Êp(x, Çy)c=vφ(x)g Õ ¸ (y)Û =4.4.7,eÞ · 2nyk vÕ ¸ ζ=√ n
2
n
2
n
− x2 √1 2π
2
n
η2
η1 n
1 1 √ n n Γ( 2π 2 )2 2
Z
∞ 0
2nt2 e−
nt2 2
nt2
n−2 2
e−
(tx)2 2
dt
îïðòñó$ôõöôõ÷$ñ
210 n 1 1 2 =√ n 2n n 2 2π Γ( 2 )2
¬ Û u$v y d à ¥
1 2
Z
n+1 Z 2
∞
e
−u
u
n−1 2
n
0
²
u = 12 (nt2 + t2 x2 )
2 n + x2
1 2 2 2 t exp − (nt + t x ) dt 2
∞
q
2u n+x2 ,
2 n + x2
n+1 2
t=
1 du = 2
Γ(
(5.5.4)
n+1 ), 2
}²Þ ζ vÕ ¸ Ø (5.5.3) Û í:v t (x). (5.5.4) Û §5.5.3 F yz{ÍÎrst= Fisher vÎefÎv}{|g æv ¬ Õ F ¸ vyzà 0
n
m
n
fmn (x) = m 2 n 2
Γ( m+n m+n m 2 ) 2 −1 (mx + n)− 2 , n x )Γ( ) Γ( m 2 2
x > 0.
(5.5.5)
Ôu$ _ Ê´ m, n ∈ N , h µ “´ m, n v F yz ”(i  m n v jk 4 µ } 4 l'm'n'o'p ), Ó Ò F . F y z ë { À r s t u$v ¼ÊÁ yz } Pq øù 5.5.5 ú η η }Ôu η ∼ χ , ! η ∼ χ , Ü mn
1
ý
2
1
ζ=
ÿg à r· η η
}íg v Õ ¸ g y s nk (nx) ~ mk η 2
1 m 2
n
mn
¬
Z
2
2 m
1 m η2 , 1 n η1
ζ ∼ Fmn .
1
2 n
m
ë
g η × g Û (4.4.8), Þ ζ v Õ ¸ (my), 1 n η1
1 m η2
∞
tkn (nt)km (mtx)dt Z ∞ n−2 m−2 1 nt mtx te− 2 (nt) 2 e− 2 (mtx) 2 dt = mn m m n n Γ( 2 )2 2 Γ( 2 )2 2 0 Z ∞ m+n m n m 1 1 −1 2 2 2 = m+n m m n x e− 2 (mx+n)t x 2 −1 dt. n 2 2 Γ( 2 )Γ( 2 ) 0 0
Û u$v yt
u = 12 (mx + n)t, Z ∞ m+n m+n m+n m+n m+n m+n 2 2 (mx + n)− 2 e−u u 2 −1 du = 2 2 (mx + n)− 2 Γ . 2 0
d à ¥
(5.5.6)
1 n 1
Û } ²
ζ
vÕ ¸
fmn (x).
(5.5.6)
)*,+-./012 211 §5.5.4 uv wxyz{|}~ w x y z Ç íg À r s u Á } { ·r æg í YZvÊV WºYZ _ ÊÁvrs ú ξ , ξ , · · · , ξ yzv}Ü
§5.5
1
2
n
n
ξ=
n
1X ξk , n
S2 =
ý
k=1
1 X (ξk − ξ)2 , n−1
(5.5.7)
k=1
~ S Àrsu$ysµ
~ê}^{Ávrs^wxy zyz N (a, σ ) v
~êv · £ v ² " à ù 5.5.1 Ø Ù ξ , ξ , · · · , ξ
} û ü y z N (a, σ ). ý 2
ξ
2
1
√
ù
Ø Ù ý ξ S
ÿ à^ è √n · ξ ¼{ , ¬ 5.5.2
2
√1 n
2
n
n(ξ − a) ∼ N (0, 1). σ ξ 1 , ξ2 , · · · , ξn n P
k=1
η1
η2 ··· ηn
{
2
(ξk − ξ)2
} û ü y z
¼Êê ξ1
= O ξ2 ··· ξn
(5.5.8) N (a, σ 2 ).
O,
.
v¡
(5.5.9)
n
√ 1 X η1 = √ xk = n · ξ, n k=1
Ó· O ê} 4 éê~}í " ξ , ξ , · · · , ξ vÕ ¸ 1
2
n
n P
k=1
ηk2 =
n P
k=1
ξk2 .
( ) n 1 1 X 2 (xk − a) p(x1 , x2 , · · · , xn ) = √ exp − 2 2σ ( 2πσ)n k=1 ( !) n n X X 1 1 2 2 = √ exp − 2 xk − 2a xk + na . 2σ ( 2πσ)n k=1
k=1
(5.5.10)
îïðòñó$ôõöôõ÷$ñ
212
Ü
x1
x2 ··· xn
= Oτ
y1
y2 ··· yn
,
4 éê~}í P y = P x , Ó P x = √ny . ê v Û 1, í · ¡¢ ,$ (η , η , · · · , η ) vÕ ¸ n
n
2 k
k=1
2 k
k=1
k
1
=√
1 e 2πσ
·
1 √ e 2π
y2 − 2σk2
2
n X
1 1 q(y1 , y2 , · · · , yn ) = √ exp − 2 n 2σ ( 2πσ) n Y
1
n
1
k=2
í ý
n X
=
øù
√
n·ξ
n X
ηk2
k=1
n P
−
η12
2
k
ÿ àN
k=1
n X
=
ξk2
k=1
(ξk − ξ)2
Ø Ù 5.5.6
√ − 2a ny1 + na2
!)
.
k = 2, · · · , n.
2 k
ηk2
yk2
n
2
1
k=2
η1 =
2
n
k=1
Ê Ùçè$ η , η , · · · , η
} Ó √ η ∼ N ( na, σ ); η ∼ N (0, σ ), ü ! η P η { k=2
1
k=1
(
√ (y − na)2 − 1 2σ2
n
n X
1 − n
ξk
k=1
ξ 1 , ξ2 , · · · , ξn
!2
=
n X k=1
(ξk − ξ)2 ,
} û ü y z
n (n − 1)S 2 1 X (ξk − ξ)2 ∼ χ2n . = σ2 σ2
(5.5.11)
N (a, σ 2 ).
(5.5.12)
Û ¬}þ
k=1
(5.5.9)
2
(n − 1)S =
{
n X
k=1
2
(ξk − ξ) =
n X
ηk2
k=2
Ê
vûü N (0, σ ) vv~}í { n−1 n−1 Ê
vûü N (0, 1) vv~} h Þ ¿ øù 5.5.7 Ø Ù ξ , ξ , · · · , ξ
} û ü y z N (a, σ ). ý (n−1)S 2 σ2
2
1
√
ÿ à · ¤À
5.5.1,
§À
2
2
n
n(ξ − a) ∼ tn−1 . σS
5.5.6
~§À
5.5.4
²Þ
¡
'¢ £ À ¿ {'8'9 ¿ v Á '¤ '¥ y }Ô§¦ Ö'¨ y'©ª T'« l d ¬¼'¬ YZ® ú ξ ~ {ξ , n ∈ N } {§¨¼Ê89¯° (Ω, F, P ) ± } Ó ¾¿ {ξ , n ∈ N } ξ Ç°±²³´µ n
n
¶¸·¸¹¸º¸»¸¼¸½¸¾¸º¸»
§6.1
¿ ÀÁÂà Ä89´µÅ p {ξ , n ∈ N } Æ ÈÉ ±´µ øÊ 6.1.1 ØÙ 67 ε > 0, Ë §6.1.1
n
ξ
Ç°±¼³Ç ×
lim P (|ξn − ξ| ≥ ε) = 0,
(6.1.1)
©ÌÍþµ p {ξ , n ∈ N } Ä89´µß ξ, Ò ξ → ξ. á ÈÉ ³´µÎÍÏÐ89 P (|ξ − ξ| ≥ ε). í ? WÑÒ Ó ±89 4 3 Û Í I(A) ç:Ô A ±:β n→∞
p
n
n
n
I(A) =
(
1,
ω ∈ A;
0, ω ∈ Ac .
©ÌÎ ÕÖO A ⊂ B CÎ I(A) ≤ I(B). Ó P (A) = EI(A). øù 6.1.1 (Chebyshev ×ØÙ ) ú g(x) ŧ¨ [0, ∞) ±ËÚ±ËÛ
ÜÝ ÎØÙ Þßàá η, â Eg(|η|) < ∞, ©Ì 67ã Þ g(a) > 0 ± a > 0, Í Ëâ Eg(|η|) ÿ à ? WÎ ·
P (|η| ≥ a) ≤
g(x)
±ËÚ
g(a)
.
(6.1.2)
(|η| ≥ a) ⊂ (g(|η|) ≥ g(a)). d Ô ä I(A) Å''Ô I(|η|A ±'≥:'a) ≤Ü'I(g(|η|) § ¡'æ ≤Ê 4 3'I(g(|η|) ç'Å ·H'≥è g(a)), 'Ô (g(|η|) ≥ g(a)) Ý'å Ô§äH≥± g(a)) â 4 3 Û ÒÞ ≥ 1. · n o P (|η| ≥ a) = EI(|η| ≥ a) ≤ EI(g(|η|) ≥ g(a)) ≤ E I(g(|η|) ≥ g(a)) ≤ . 3 Å ¼ Ê Ë Ì ' Á ' é ± 3 Î ' 8 9 § ¿ ä ' ± ' ì ' í î ¯ Ø à 4 4 Û Û è â'ê'ë Chebyshev g(|η|) g(a)
g(|η|) g(a)
g(|η|) g(a)
213
Eg(|η|) g(a)
214
ô
6.1.1
ØÙ Þßàá
î,ï$ð ð,ñòó
õ Ìþ â
η ∈ Lr (r > 0),
P (|η| ≥ x) ≤ E|η|r · x−r ,
∀ x > 0.
(6.1.3)
öà è Chebyshev 4 3 Û ä$Ü g(x) = x ²Þî Chebyshev 4 3 Û÷øù Î úÍݺ¾¿ûü Ýý î øÊ 6.1.2 ú {ξ , n ∈ N } þÞßàá p Î S = P ξ . ØÙÿ è Ý p {a , n ∈ N } Ý p {b , n ∈ N }, ã Þ r
n
n
k
n
k=1
n
n
Sn − a n p → 0, bn
² lim P
(6.1.4)
Sn − a n ≥ ε = 0, bn
∀ ε > 0,
(6.1.5)
ú'Í þ {ξ , n ∈ N } û ü'û'ü Ý'ý î Ô§ä {a , n ∈ N } µ þ ä't Ý 'Î {b , n ∈ µ ýt Ý î N } þ ûü Ýý ± ÈÉ þÅ Þßàá p {ξ , n ∈ N } ÿ è ä t Ý {a , n ∈ N } ýt Ý {b , n ∈ N }, ã Þ (6.1.4) Û Ò± ÔîØÏÙ Ìúͼ þ U s a = ES , b = n, n ∈ N , Ó ¾¿ ã Þ ξ ∈ L , n ∈ N, õ n→∞
n
n
n
n
n
n
n
1
n
n
n
Sn − ESn p →0 n
Ò± Ôî úͺ¼ ûü Ýý ±î ô 6.1.2 (Markov v ) ØÙ Þßàá p lim
(6.1.6)
{ξn , n ∈ N },
DSn = 0, n2
õ Ìþ â Ø (6.1.6) Û ±ûü Ý ý Òî ÿ à è Chebyshev 4 3 Û ä$Ü g(x) = x , úÍÒ²Þ Î 67 CÎ Ëâ n→∞ n→∞
2
n P Sn −ES ≥ ε = P (|Sn − ESn | ≥ nε) ≤ n
E(Sn −ESn )2 n2 ε2
â (6.1.7)
ε > 0,
O
→ 0, í â Ø (6.1.6) Û ±ûü Ýý Òî û'ü Ý'ý ä â' p {ξ , n ∈ N } äH± Þ'ß'à'á Ç'°'±( è Markov ÷67 ÎíżÊL Û Ç þêë ± ¿î ô 6.1.3 (Chebyshev gv ) Ø Ù p {ξ , n ∈ N } är± Þgßgàgág_g_ 4 ÿ è Ì Ý C > 0, ã Þ Dξ ≤ C, ∀ n ∈ N , õ Ìþ â Ø (6.1.6) Û ±ûü Ý ý Òî n
n
n
=
1 DSn ε2 n2
!ö"#! 215 ÿ à$ {ξ , n ∈ N } ä± Þ ßàá__ 4 Îí P DS = Dξ ≤ nC, % â Ô (6.1.7) Òî h $ Markov ûü Ýý Þ Chebyshev ûü Ýý î ô 6.1.4 (Bernoulli v ) ØÙ ζ ç: n Á Bernoulli &' ä ± ä @ Ý Îý â ζ §6.1
n
n
n
k
k=1
n
n
n
p
→ p.
(6.1.8)
ÿ à úÍ " Ý( ζ = P ξ := S , Ô,ä {ξ } Å)*Ò±ûü+ Ý þ p ± Bernoulli Þßàá Î Ó Eξ = p, Dξ = pq ≤ 1. í$ Chebyshev û ü Ýý Þ â Ø (6.1.6) Û ±ûü Ýý ÒÎ % â (6.1.8) Òî úÍ,)Ê ýtÌ Ý b 6= n ±î ô 6.1.5 ú'â )'.-/'Î è0 k Ê.-/§ä1 â 1 Ê.23 k − 1 Ê43'î6587 Ê-!/,ä²)3Î ζ ç:í É ± n Ê3,ä±2!3Ê Ý îÑýO r > CÎ n n
k
n
n
k
k=1
k
k
n
1 2
n
â
ζn −Eζn lnr n
p
ÿ àNúÍ9 Þßàá ξ þ à ØÙ:5 0 k Ê-!/,ä É 2!3Î þÜ ξ = 1; ØÙ É 43ÎþÜ ξ = 0. Å {ξ } Å)*Ò± Bernoulli Þßàá Î Ó ûü+ Ý þ p = ± Bernoulli ; î ÕÖ â ζ = P ξ , Ó ξ →0.
k
k
â
k
Ô,ä í
k
n
1 k
k
Eξk = k1 ,
k
Dξk =
Ì Ý ³î ü ! $ C>0þ
n
1 k
−
1 k2
< k1 ,
Dζn =
n P
k
k=1 n P
Dξk <
4 3 Û à 67 Chebyshev k=1
k=1
1 k
ε > 0,
≤ C ln n,
O
n→∞
CÎ Ë
ζn − Eζn Dζn C 1 P ≤ 2 2r−1 → 0, ≥ ε = P (|ζn − Eζn | ≥ ε lnr n) ≤ r 2r 2 ln n ε ln ε ln n n
i = ß
ζn −Eζn lnr n
p
è ,äÎ â ÿ à þ < Î ^ è ô
→ 0.
6.1.6
ζn p ln n →
1.
lim P (|ηn − ln n| ≥ ε ln n) = 0,
∀ ε > 0.
n→∞
lim (Eηn − ln n) = lim
n P
1 j
Ô,ä c þ Euler Ì Ý ÎíO n > üCÎ 67 ü ! O n > üCÎþ â ε ln n + (ln n − Eη ) > n→∞
n→∞
j=1
n
− ln n
!
= c > 0,
ε > 0, 1 2 ε ln n.
Ëâ
î,ï$ð ð,ñòó
216
P (|ηn − ln n| ≥ ε ln n) ≤ P (|ηn − Eηn | ≥ ε ln n + (ln n − Eηn )) ≤ P |ηn − Eηn | ≥ 21 ε ln n ,
ü ! t?î §6.1.2 @AÂà B è úÍ,CD Þßàá p ±EF)³´µî øÊ 6.1.3 ØÙ Þßàá ξ, ξ ∈ L , Ô,ä r > 0, Ó n
r
E|ξn − ξ|r → 0,
ýG g Þ ßC gÎJàgIá G p Ä{ξé, ´n µ∈ Î N } Ä Ò r H égg´gµ ß Þgßgàgá ξ, Ò ÷ r=1 þ Ó þ ξ → ξ. 67Þßàá ξ ∈PL , ØÙÜ ξ = P ≤ξ< , n ∈ N, Ìõ þ â n
L
(6.1.9)
O
L
ξn →r ξ.
n
n
∞
r
m=−∞
m−1 2n
m−1 2n
m 2n
∀ ω ∈ Ω, ü þ è Î ÿ é´µ´µß ξ ±LM ! â ξ −→ ξ. K 6 7 ξ∈L ,Ë è rH N Þßàá p î Äg8g9g´gµ O g´gµPg°gÿ èQR g(S ? WgÎT$ Chebyshev 4 3UgÒ è %VW S XY 6.1.2 r HO ´µZ[Ä89´µî ÅÎJ\P 4] îJ\ QR S ô 6.1.7 ^ 89¯° (Ω, F, P ) þ_ ° (0, 1) ` ± 7 N 89¯°Î % â n
a
|ξn (ω) − ξ(ω)|r ≤
Lr
r
Ω = (0, 1),
ξ(ω) = 0,
∀ ω ∈ (0, 1),
!
ξn (ω) =
bW JÎ c 6 7 ε > 0, O de ξ → ξ; Å p
1 2rn ,
n→∞
F = B1 ∩ (0, 1), n2 ω,
n2
2 n
CÎ Ëâ
P = L.
ω ∈ (0, n1 ];
− ω , ω ∈ ( n1 , n2 ];
0,
ω ∈ ( n2 , 1).
P (|ξn − ξ| > ε) ≤ P (ξn > 0) =
2 n
→ 0,
n
E|ξ − ξ| = Eξ ≡ 1, Ä ´ µ f 4 ξ O ξ. ! $ g d H Î ú Í é ,h < ) RO ´µ±isjkî Lebesque lm ´µ Q n Îpoq'´'µ n Fatou C n cg'ú'Íh <O '´µr ¨ s é'Îut'Í èvà Ü Ý < ä Ëâ d YZÎ úÍ«wìtͱxyzUî
de
n
n
n
§6.1
!{"#! |} CD Þßàá p ±)~rxî XÊ 6.1.4 G Þßàá p {ξ , n ∈ N } Å)~±Î Q
217
n
lim sup E (|ξn |I(|ξn | ≥ a)) → 0,
(6.1.10)
a→∞ n∈N
úÍ,)~± > é ÔS XY 6.1.3 Þßàá p {ξ , n ∈ N } )~± > Ó é ÔÅSJc
± ε > 0, Ë ÿ è δ = δ(ε) > 0, ã V c
Ô P (A) < δ ±Ô A, Ëâ n
sup E (|ξn |I(A)) < ε,
(6.1.11)
sup E|ξn | < ∞.
(6.1.12)
n∈N
S ^` æ ÔÒÎkc
± ε > 0, Ë ÿ è ãW Î Vÿ égÔ A V gÔ P (A) < δ, ggÅ Ëg â é (6.1.11) UgÌÒg îJ$ è C > 0, ã sup E|ξ | < C, a> ,õ â gÅ$ (6.1.11) UÒ V P (|ξ | ≥ a) ≤ < < δ, ∀ n ∈ N , n∈N
E|ξn | a
n
de
(6.1.12)
C δ
n
n∈N
U
δ = δ(ε) > 0,
C a
sup E (|ξn |I(|ξn | ≥ a)) < ε,
)~î {ξ } |} ÎT$
n∈N
n
(6.1.10)
U W ÎJc
±
ε > 0,
é
a
> üÎJ â
sup E (|ξn |I(|ξn | ≥ a)) ≤ ε,
â
n∈N
E|ξ | ≤ E (|ξ |I(|ξ | < a)) + E (|ξ |I(|ξ | ≥ a)) ≤ a + ε, ∀ n ∈ N , â (6.1.12) UgÒgîJ ¡gÎ é a δ = , õ Ì égÔ A gÔ P (A) < δ, Ëâ n
n
n
n
n
ε a
E(|ξn |I(A)) = E(|ξn |I(A ∩ (|ξn | ≤ a))) + E(|ξn |I(A ∩ (|ξn | > a)))
% â (6.1.11) UÒ≤î aP (A) + E(|ξ |I(|ξ | > a)) < 2ε, ∀ n ∈ N , $!g n 6.1.3 ±zU¢!£¤¥Î úÍ)~r±¦§ g '¨ ± > ÔS ©ª 6.1.1 Q ÿ è α > 0, ã V k
n
{ξn }
)~î
n
sup E|ξn |1+α < ∞,
n∈N
« ï!¬ ð,ñòó , ©ª 6.1.2 Q ÿ èÞßàá η ∈ L , c
x > 0, Ëâ sup P (|ξ | > x) ≤ P (|η| > x), k {ξ } )~î e ` ¦§ <®¨¯Ë°± ÎT²!³´ ÷þµ¶ î XY 6.1.4 @Ag·¸¹º» Q c r > 0, Þgßgàgá¼½ {|ξ | , n ∈ N } )~¾ ξ −→ ξ, k ξ ∈ L , ξ −→ ξ. \P¾ Q c r > 0, â ξ ∈ L , ξ −→ ξ, k ξ ∈ L , ξ −→ ξ. S þ¿¨¯!K § n ¾ úÀÁéìf Þßàá¼½® a.s. Âà r¾ÄtÅ g và ÜÝ < ä ®ÆÇ íí Âà ¾J È9ÉS ã V ÊU 218
1
n
n∈N
n
n
p
n
r
n
r
n
n
r
Lr
p
Lr
r
n
ξ (ω) = ξ(ω) ° Ë ® ω ®ÌÍ É)§xy þ lim Îî úÀÏ èÐÑ®0 4 h <K 0® Ò ! Ó Ô Õ Ö Âà rJî e ¨¯ ¾JÅ ξ −→ ξ × ¾ ÿØ ½ {ξ } a.s. Âà f ξ. KÙ ),¾JÅ ξ −→ ξ, {|ξ | } )~ × ¾T$ Fatou C n % V n
n→∞
p
n
nk
p
n
n
r
E|ξ|r ≤ E(lim inf |ξnk |r ) ≤ lim inf E|ξnk |r ≤ sup E|ξn |r < ∞,
Û$ g {|ξ | } )~¾ de c
® ε > 0, Ü ÿØ ξ∈L . Ú V ¨ cξ
−→ ξ. Î P (A) < δ ® Î A, ÜÞ δ = δ(ε) > 0, Ý sup E (|ξ | I(A)) < ε, E (|ξ|I(A)) < ε. ß $!g ξ −→ ξ, de c ` ε > 0 δ > 0, ÿØ n ∈ N , Ý à n ≥ n , Þ de
r
n
k→∞ Lr
k→∞
n
n
n∈N
p
n∈N
r
r
n
0
$ ` n $
Cr
°á U¾ %V
0
P (|ξn − ξ| > ε) < δ.
E|ξn − ξ|r = E (|ξn − ξ|r I(|ξn − ξ| ≤ ε)) + E (|ξn − ξ|r I(|ξn − ξ| > ε))
de
L
r ξn −→ ξ.
≤ εr + Cr E ((|ξn |r + |ξ|r )I(|ξn − ξ| > ε)) < εr + 2Cr ε,
\P¾ Q ξ −→ ξ, k bW ξ −→ ξ ∈ L . $ C °á U V sup E|ξ | ≤ C sup E (|ξ − ξ| + |ξ| ) < ∞. E)âã¾!c
® ε > 0, Ü ÿØ n ∈ N , Ý à n ≥ n , Þ E|ξ − ξ| < ε, ä $ ξ , ξ ∈ L W ¾Jcå ® ε > 0, æ Ø δ = δ(ε) > 0, Ý Và P (A) < δ, Þ n
p
Lr
n
n
n∈N
r
r
r
r
r
n
n∈N 0
n
r
0
n
r
r
E(|ξ|r I(A)) < ε,
max E(|ξn − ξ|r I(A)) < ε,
KÙ ),¾ %W cçÎ P (A) < δ ® Î A, Þ I(A)) ≤ C (E(|ξ| I(A) + E(|ξ − ξ| I(A))) < 2C ε, ∀ n ∈ N , $!E(|ξ å n |6.1.4 W {|ξ | } )~è ©ª 6.1.3 Q ξ é {ξ } êëìíîïðñ ¾ Üæ Ø) Hò ¾ókÅ ξ ¾ QRô §õö÷ø áù S ξ× n
r
r
r
n
1≤n
n
r
r
r
n
p
n
−→
úûüý!þ{ÿý!þ 219 ~ (2) E|ξ − ξ| → 0, n → ∞; (3) Eξ → Eξ, n → ∞. (1) {ξ } S!å n 6.1.4 W (1) ⇔ (2). |Eξ − Eξ| ≤ E|ξ − ξ|, W (2) ⇒ (3). À ¨ (3) ⇒ (2). !g ξ é {ξ } êëìíîïðñ ¾ de 0 ≤ (ξ − ξ ) ≤ ξ, ä W ξ −→ ξ, §6.1
n
n
n
n
n
n
n
+
p
n
p
(ξ − ξ ) −→ 0, m ÂÃ å n ¾ V
Í (3), V E(ξ − ξ )E(ξ→−0,ξ g) É →Þ 0,(2) Ëè 6.1 1. (1) ξ → ξ ⇒ ξ − ξ → 0; +
n
n
n
p
+
−
p
n
n
p
p
(2) ξn → ξ, ξn → η ⇒ P {ξ = η} = 1; p
p
(3) ξn → ξ ⇒ ξn − ξm → 0 (n, m → ∞); p
p
p
(4) ξn → ξ, ηn → η ⇒ ξn ± ηn → ξ ± η; p
(5) ξn → ξ, k p
p
⇒ kξn → kξ;
p
(6) ξn → ξ ⇒ ξn2 → ξ 2 ;
⇒ ξ η → ab; (8) ξ → 1 ⇒ ξ → 1; (9) ξ → a, η → b, a, b , b 6= 0 ⇒ ξ η (10) ξ → ξ, η ⇒ ξ η → ξη; (11) ξ → ξ, η → η ⇒ ξ η → ξη. 2. ξ → ξ !"#$%&' p
p
p
(7) ξn → a, ηn → b, a, b p
n n
−1 p n p
n
p
n
−1 p n n →
n
p
p
n
p
n p
p
n
ab−1 ;
n
n n
p
n
E
|ξn − ξ| → 0. 1 + |ξn − ξ|
( ξ )* Cauchy #+,.-/012 p (x) = n π(1 + n x ) , n ≥ 1, ξ → 0. 4. ( {ξ } 24345444446474,.8494:4;4<4!=/4041= p(x) = e , x > a, > η = min{ξ , · · · , ξ }, η → a. 5. ( {ξ : n ≥ 1} 4345444446474, P (ξ = log n) = P (ξ = − log n) = 1/2, (n = 1, 2, · · ·), {ξ : n ≥ 1} )*?@ ABC 6. ( {ξ : n ≥ 1} 35!6474, 3.
n
2 2
n
−1
p
n
−(x−a)
n
n
p
1
n
n
n
n
n
n
n
1 1 1− n , 2 2 1 P (ξn = n) = P (ξn = −n) = n+1 , n = 1, 2, · · · . 2 P (ξn = 1) = P (ξn = −1) =
D {ξ : n ≥ 1} E )*?@ ABGF ( {ξ : n ≥ 1} HI:J!44446474CK4 %&'2 P n
7.
n
n−2 D
{ξn : n ≥ 1}
n
ξk
k=1
→ 0,
n → ∞.
)*?@ AB!4"
220 8.
(
{ξn : n ≥ 1}
35<#+!44674,
f (x),
ξ1 + · · · + ξ n n
= f (a).
Z67[,.\' A ]^!_`2 p, > ( 1, aYb n cdb n + 1 cZ[ ξ = 0, -f . Q {ξ , n ≥ 1} )*?g ABC 10. ( {ξ , n ≥ 1} 35!6474, ξ !#+2 9.
(Y
lim Ef
Eξ1
« L!¬ MN OP = a, QRSTUVH:JW4X14
n→∞
Bernoulli
A
n
e]^
,
n
n
n
P
ξn =
(n + 1) n
k/2
=
n , (n + 1)k
) *?@ ABC 11. ( {ξ , n ≥ 1} 35<#+6474,.8494!4;<4#4+42
k = 1, 2, · · · ,
{ξn , n ≥ 1}
n
P (ξn = k) =
-[
−1
c , k2 log2 k
k = 2, 3, · · · ,
D {ξ , n ≥ 1} E )*?@ ABGF 12. ( {ξ , n ≥ 1} hHh7hih:hjh
n
∞ P
(k ln k)−2
k=2
.
n
j 6= k, E(ξj ξk ) ≤
n
s tuvuwux u y{z îïðñ ¾ |.} à{y{z tÀ ®{~{{ y{z îïðñ¼½®Âà r{ Å} àyz ÷ ®~
¼½®Âà rè · §6.2.1 ξ é {ξ , n ∈ N } ë6½6î6ï6ð6ñ ¾ ÷ ®~{{
6ë F (x) é {F (x), n ∈ À à É ~ÂÃ è N }. } § 6.2.1 §6.2
n
}Ø ïðñ¾£¼¤ ½ ¡¢ î ®
n
¾ Þ n→∞×
ξ(ω) = 0,
ξn (ω) = − n1 ,
ξn (ω) → ξ(ω),
∀ ω ∈ Ω,
∀ ω ∈ Ω,
(6.2.1)
ÅÂÉÃ ξ, } ~
¾¥É¦§ ¨î¾ï©ðÀ ñ® {ξ , n ∈ N } ~ ÂÃ ξ ® ®~ {ξn , n ∈ N } n
ú ª«ý!þ
½®¬ ÅÉ §6.2
Fn (x) = P (ξn < x) =
¾
®~
è ®É¾ À¯°
ξ (
221
0, x ≤ − n1 ;
1,
F (x) = P (ξ < x) =
x > 0.
(
0, x ≤ 0;
1, x > 0.
lim F (x) = F (x), ∀ x 6= 0; ®É± Þ ² {³ ¯ ¾ À °´ à{µ ÷{ lim®{~F{(0)
= ½1 6=¶{0¶=ÂFÃ(0). F (x). ·{¸{¹ Ó x = 0 É è F (x) ®°º»¶ ¤ C(F ) ³¼
F (x) ®º»¶Ì ¾ À½¾¿ÀÁå ÃÄ 6.2.1 {F (x), n ∈ N } É ½ åÅÂØ R Æ®ÞÅÇìÅÈ®ÅÉźŻÅ
¾ ÀÊ æ Ø §åÂØ R Æ®ÞÇìȮɺ»
F (x), ÝË n
n→∞
n→∞
n
n
∀ x ∈ C(F ),
lim Fn (x) = F (x),
ÌÎÍ è
(6.2.2)
Ð ë F (x) → F (x), Ñ Í F (x) É {F (x)} ®ÎÏά ÒÓÔÕ ·¸ ÀØ ²Ö× ÞÝØ “~
” ² §ÙÚè ² É ë Û 6.2.1 ~
½®Ï¬° åÉ ~
è ÀÁ 6.2.2 {Fn (x)}
ÏÂÃÎ
Fn (x) =
}
n→∞
w
F (x),
0, x+n 2n ,
1,
n
n
x ≤ −n;
−n < x ≤ n; , x > n.
∀ n ∈ N;
F (x) ≡
1 . 2
É ~
¼½ ¾ ÑÜ F (x) → F (x), ®É F (x) ± ° É ~
è Ý{Þ Æ ¦ ¶{ß{à ¾ À ¯ á¿ ~{Âî Ⱦ â{¤¾¿{ÀÁå{ ÃÄ 6.2.2 À{Ê {F (x), n ∈ N } É ½{~{{{
¾ Ñ{Üæ Ø ~{{{
F (x), Ý ËÀÊ F (x) → F (x), É ÀÍ {F (x)} ~ÂÃ F (x), Ðë F¾J(x) → F (x).É {F (x), n ∈ N } îïðñ¼½ {ξ , n ∈ N } ®~
¼½ F (x) ¾ Ì Å ¾ Í îïðñ ξ ®Î~ÎÎÎ
F (x) → F (x) × {ξ } ~ÎÂà ξ, ÑÎÐë ξ → ξ. Å ·{¸ ¾ã ~{ÂÃ É îïðñ®~{{
½{äå®ÂÃæ ʾ㩠°´ îïðñ |Kç 宬æ Êè {Fn (x)}
w
n
n
w
d
n
n
n
n
n
d
n
d
n
n
222
Û 6.2.2 ~Âð´èé êë  à è À §è 6.2.3 (Ω, F, P ) ëìíî êëï å ¾ ð Ó ξn (ω) =
«L!¬ MN OP
(
0, ω = ω1 ,
Ω = {ω1 , ω2 }, ( 1, ω = ω1 , ξ(ω) = 0, ω = ω2 .
∀ n ∈ N;
1, ω = ω2 ,
é ξ {Ü ñ{ò{ó{®
É ë À ® Bernoulli ~{ ¾ô£{¤ F (x), ξ → ξ. Þ õö÷ 0 < ε < 1,|ξ Ü(ω)Þ − ξ(ω)| ≡ 1, ∀ ω ∈ Ω, 1 2
ξn
d
Fn (x) ≡ F (x),
Å{} Þ
d
Fn (x) →
n
n
£¤
P (|ξ − ξ| ≥ ε) ≡ 1, ∀ n ∈ N , ² ø ù ú ξ 6→ ξ. À ~ÂÃû´èé êë ÂÃ è ®É¾ Þ ¾ À± Þ Ãü 6.2.1 ÀÊ ξ → ξ, Ìý Þ ξ → ξ. þÿ . ξ ξ ~
~ë F (x) é F (x). ¯¾ õö÷ n
p
n
p
d
n
n
n
£¤
∀ n ∈ N,
n
y < x,
Þ
(ξ < y) = (ξ < y, ξn < x) ∪ (ξ < y, ξn ≥ x) ⊂ (ξn < x) ∪ (|ξn − ξ| ≥ x − y),
ò â ξ → ξ ¯ ¾ õö÷ z > x, Þ p
F (y) ≤ Fn (x) + P (|ξn − ξ| ≥ x − y),
n
ÀÊ £¤
F (y) ≤ lim inf Fn (x). n→∞
Ë Æ ¾ ÑÜ x ∈ C(F ),
lim sup Fn (x) ≤ F (z). n→∞
y ↑ x, z ↓ x,
Þ
F (x) ≤ lim inf Fn (x) ≤ lim sup Fn (x) ≤ F (x). n→∞
n→∞
∀ x ∈ C(F ),
lim Fn (x) = F (x),
n→∞ d
À ¤ c ³Î¼ c îïðñ è ØÎ ~ÎÂà ΠΠêÎë ÂÃÎäÎåÞ ÀÁ áùæ Ê Ãü 6.2.2 ξ → c áù ξ → c. þÿ !å 6.2.1 ¯ ξ → c èé ξ → c, £¤Á Þ èéæ Êè ·¸ c îïðñ~
ë ξn → ξ.
p
d
n
n
p
n
d
n
F (x) = I(x > c) =
(
0, x ≤ c;
1, x > c.
ú ª«ý!þ © Þ ø ûº»¶ §6.2
x = c,
£¤Å
× ¾ Þ
d
ξn → c (
0, x < c;
lim Fn (x) =
õö÷
ε > 0,
n→∞
Å
n→∞
× ¾ Þ
223
1, x > c.
P (|ξn − c| ≥ ε) = P (ξn ≥ c + ε) + P (ξn ≤ c − ε)
Þ
= 1 − Fn (c + ε) + Fn (c − ε + 0) → 0,
p
Ø êÂÃé ~ ÂÃäå ¾ À Þ ÀÁ à Ãü 6.2.3 ξ é {ξ , n ∈ N } É îïðñ¼½ ¾ ξ → ξ, Îõ r > ý à çÎÉ {|ξ | } âè 0, E|ξ | → E|ξ| ~ ý !à çõÎÉ ìíîïðâñ"è # {ξ, ξ , n ∈ N }, ξ → ξ, Eξ → Eξ ~ {ξ } Ãü §6.2.2 $%& yÎz ~Î)*Þ+,- è . ÏØ ÐÒÓ0/1Î~ÎÎÎ
# Î ' Î
( ~)*2 õ '
#3¶)*2äå 4 è ½Î ßÎà Ï)*ÞÎæÎ56 öè7 8ÀÎÁ Îæ ÉκλÞÎÇìÎÈÎ
#Ï)*~ ý à ç9 Ãü 6.2.4 F (x) é {F (x), n ∈ N } ({:# å{Â:; R Æ::<{Çì{È:{É{º »
! Ì F (x) → F (x) ~ ý=ç9 ( õ C(F ) > ø?@ A D, < ξn → c.
d
n
n
r
n
r
n
r
d
n
n
n
n
n
w
n
lim Fn (x) = F (x),
n→∞
þ ÿ .ý= 2 }è0B ~2 è0Cç9 Eõö÷ y, z ∈ C(F ), ÑÜ y < x < z, F<
£¤G
∀ x ∈ D. (6.2.4)
(6.2.3)
D1! ö ¡
x ∈ C(F ) − D,
F (y) ≤ F (x) ≤ F (z), ! ç 9 â n → ∞ H! (6.2.4) Ë F (y) ≤ lim inf F (x) ≤ lim sup F (x) ≤ F (z). E x ∈ C(F ), £¤G y ↑ x, z ↓ x H!IË (6.2.2) ! £¤ F (x) → F (x). J ½KLM <æ êN é õöè Ãü 6.2.5 (Helly O:P Ã{ü ) å{Â:; R Æ: ö{÷ :#{::<{Ç:ì{È{É{º{»
Fæ ; {F (x)} ø # {F (x)} é ø å {F (x), n ∈ N } F(ÏQ! ; R Æ<ÇìÈɺ»
F (x), RË F (x) → F (x). n
n→∞
n
n
n
n→∞
n
w
n
n
n
nk
w
nk
224
þ ÿ #! £¤ Ç
#! {F1,n }
SLET M N OP VU R Æ<
A Ðë D = {r , r , · · ·}. E {F (r )} ( ø < Ç
棤; ;# © {F (rø )} )*> øW
G(r ).øEW {F (r )} X( ø < #æ ! £¤ . H#< {F (r )} )*>
G(r ). ·¸ {F } ( ÁZ ! â ËlimF[ (r# ){F= G(r},),m ∈limNF, ð(r\ ) = G(r ). 1
1,n
1
2,n
n
n
1
2,n
À Y » ò õ] ø
2
1
1
1,n
2
1
2
1
2,n
n
2
2,n
2
m,n
m,
{Fm,n } ⊂ {Fm+1,n },
F<
² ( ¨ ! .Ë^
k = 1, 2, · · · , m .
lim Fk,n (rk ) = G(rk ), n
{Fn }
∀ m ∈ N,
(6.2.4)
ÀÁ [ # ···
F1,n
Fm,1
···
Fm,2
···
···
···
···
···
···
···
···
F1,1
F1,2
F2,1
F2,2
···
···
···
···
F2,n
· · · Fm,n
···
è ¯ ! ²ø_ # õ `a ÆDbcD"# {F } d } ( RË (6.2.4) D 1 # è Ü! {F , n ≥ 1} ( {F } #! £¤ lim F (r ) = G(r ); {F } £ ¤ lim F (r ) = G(r ); · · · ; e! H {F , n ≥ 2} ( {F } #! Î #! £Î¤ lim F (r ) = G(r ). fÎä! {F } gh {F , n ≥ k} ( {F } #-< ÀÁ 2i {F } n,n
n
n,n
n,n
1,n
2,n
n,n
n
n
k,n
n,n
n
n,n
2
k
n,n
1
1
2
k
n,n
n
õ k j G(x) ( o ; ! .
n
x = rk ∈ G
F (x) =
Ì
õ k ( E F (x) ;
∀ rk ∈ G.
lim Fn,n (rk ) = G(rk ),
(6.2.5)
<l  <ÇmÈ
n G(rk ),
sup G(rk ),
∀ x = rk ∈ G,
(6.2.6)
x 6∈ G,
@ l  A <ÇmÈ
n £¤ 6.2.4 R DÆ G(x) pq! (6.2.5) rl ¯ F (x) → F (x). l  (6.2.6) 7 F (x) ɺ»n ¹Ãl ü \ £ RØsÃt ü Í hvÀuÊ wxy . Ìõö÷ l  6.2.6 (Helly Oz ) ~
# F (x) → F (x), ; R Æ<Ǻ»
g(x), F< Z Z F (x)
x∈R
rk <x
w
n,n
d
n
lim
n→∞
g(x)dFn (x) =
R
g(x)dF (x).
R
(6.2.7)
{ ª«|E} 225 þ{ÿ â{¤:~ :Ø l 6.2.7 \ ~ 1 t l ! o ;{¾¿: tn 0 ~ÎÎÎ
# F (x) → F (x), £Î¤ F (x) (Î~ÎÎÎ
n
<Îæ8 7 ¯ ! âΤU (Ω, F, P ) ¡ h Îå (0, 1) Æ ÷ î êÎëÎï å ( Ω = (0, 1), F = B ∩ (0, 1), P h Lebesque ), = F (ω), ξ (ω) = F (ω), ∀ n ∈ N , ∀ ω ∈ (0, 1). Ì ξ r ξ ξ(ω) Å~ÅÅÅ
Å~h F (x) r F (x). H< © ω = F (x), x ∈ R. Å
!< ω = F (x) x := F (ω), ω ∈ (0, 1) mÅÈ! . h ! F (x) → F (x) âΤ ¿ lim F (ω) = F (ω), ω ∈ C(F ). ?@ å (0, 1), £¤ ξ = F ( õ Lebesque ) )* C(F ) ⤠ω 6∈ C(F ) H ξ(ω) r ξ (ω) l  ! À© .Fl ξ = F . .  h 0, RÎË ξ r ξ Î~ÎÎÎ
d } ~h F (x) r F (x), ÑÎÜ ξ = F Î )*Î ξ = F . g(x) hκλ<ÎÇÎÎ
! £Î¤ g(ξ ) Î)*Î g(ξ). 8 Lebesque )*l ! Ë R R lim g(x)dF (x) = lim Eg(ξ ) = Eg(ξ) = g(x)dF (x). Á¡KL¢ £ =¤ àn Ãü 6.2.7 ($:%:& Ã{ü ) 1 . F (x) r {F (x), n ∈ N } F:({~{{{
:! f (t) r {f (t), n ∈ N } ( © . õ '
n ÀÊ F (x) → F (x), Ì < §6.2
◦
d
n
−1
−1 n
n
n
n
−1
d
n
−1
n
−1
−1 n
n→∞ −1 n
−1
−1
−1
n
n
n
−1
n
−1 n
n
n
n→∞ R
n
n→∞
◦
R
n
d
n
n
lim fn (t) = f (t),
∀ t ∈ R,
(6.2.8)
ÑÜ ²¥ ) *2 ;ö÷ <ǦåÆ õ t §D1n ÀÊ {f (t), n ∈ N } (§#'
! {F (x), n ∈ N } ( © . õ ~ 2 . Ì
! Àʨ; ø § ø ; t = 0 ºõ»©l £Âõ; R Æ
f (t) RË (6.2.8) D 1! f (t) (§ '
! ÑÜ ~
F (x), < F (x) → F (x). þÿ 1 . ÀÊ F (x) → F (x), Ì õö÷ t ∈ R,
g (x) = e F(l Â; R Æ<Ǻ»
! £¤ Helly l 1Ë (6.2.8) n © ² ¥ )*2 ;ö÷ <ǦåÆ õ t §D1n ¯©õ ∀ t > 0, U ²¥ Ǧ å ¡ h [−t , t ]. ö¾ ε > 0, â ¡ ~ Ò ª
A ∈ C(F ), RË R dF (x) = F (−A) + 1 − F (A) < ε. n→∞
◦
n
n
d
n
d
◦
n
t
0
0
0
|x|>A
£¤G .<
lim F (A) = F (A), Ò n ~ H ! R < n→∞
n
|x|>A
lim Fn (−A) = F (−A),
n→∞
dFn (x) = Fn (−A) + 1 − Fn (A) < 2ε.
itx
S«ET ¬E®¯
226
R R |fn (t) − f (t)| = R eitx dFn (x) − R eitx dF (x) R R R R ≤ |x|>A dFn (x) + |x|>A dF (x) + |x|≤A eitx dFn (x) − |x|≤A eitx dF (x) ,
£¤ . ©EG n → ∞ H! R õ |t| ≤ t §° 0. e .<
A itx dFn (x) −A
−
0
¡
RA
−A
eitx dF (x)
eitx − eity = eity e−it(x−y) − 1 ≤ |x − y| .
± @ 0! R Ë < − x ) < ε, j = 0, 1, · · · , m − 1. (
−A = x0 < x1 < · · · < xm = A
t0 (xj+1
sup
|t|≤t0
≤
A itx dFn (x) −A e
m−1 P
²³ <
m−1 P itx e dF (x) sup ≤ −A
RA
j = 0, 1, · · · , m − 1 .
j=0 |t|≤t0
R R xj+1 xj+1 itx xj e dFn (x) − xj eitx dF (x)
j=0 |t|≤t0
R Rx x sup xjj+1 eitxj dFn (x) − xjj+1 eitxj dF (x) := I1,n + I2,n + I3,n .
j=0 |t|≤t0
m−1 X Z xj+1 xj
j=0
I2,n < ε .
I3,n =
−
eitx − eitxj < ε ,
R m−1 R P x x sup xjj+1 eitx − eitxj dFn (x) + sup xjj+1 eitx − eitxj dF (x)
j=0 |t|≤t0 m−1 P
+
sup
|t|≤t0 xj ≤x≤xj+1
I1,n ≤
ÜRË
j
sup
. R<
xj ∈ C(F ), j = 0, 1, · · · , m,
m−1 X
m−1 X sup eitx − eitxj dFn (x) < ε
|t|≤t0
.´µ
I3,n .
¯
j=0
Z
xj+1
Fn (x) = ε
Z
A
−A
xj
dFn (x) ≤ ε .
m X sup eitxj ((Fn (xj+1 ) − Fn (xj )) − (F (xj+1 ) − F (xj ))) ≤ 2 |Fn (xj ) − F (xj )| .
= n ± Ò H! < t (x − x ) < ε, j = 0, 1, · · · , m − 1, ¶· < I < ε|F. ¸(xq)Æ− F (x! )| Ë < (6.2.8), õ j =|t|0,≤1,t· · ·§, m−D11, n {F (x), n ∈ N } (ÏQ!¹¶· ¨; l  R Æ<ÇmÈɺ» 2 . º» Fe(x) r {F (x), n ∈ N } § ø¼ # {F (x), k ∈ N }, RË e ¯ Fe(−∞) ≤ 0, Fe(∞) ≤ 1. C½ F (x) → F (x).
j=0 |t|≤t0
0
j+1
j=0
j
n
j
j
ε 2(m+1)
3,n
◦
0
n
n
nk
w
nk
º»
;
α := Fe (∞) − Fe (−∞) < 1.
¾ Á º»ÜRË (6.2.8) D1!¹¶· ¨ ; ¿ À ¸ 0 < ε < 1 − α, δ > 0, R Ë f (t)
t=0
1 2δ
Z δ ε f (t)dt > α + . −δ 2
(6.2.9)
f (0) = 1,
ÑÜ õö
(6.2.10)
§6.2
{ÂÃ|E}
Ò F H!<
nk (x)
·¸Å
Ä.Æ<
w → Fe (x),
¤ q
(6.2.9)
!¹Ä ¨;
b>
4 εδ ,
RË
±b ∈ C(Fe ),
αk := Fnk (b) − Fnk (−b) < α + 4ε .
R δ itx −δ e dt ≤ 2δ;
R δ itx 2 −δ e dt = x sin tx ≤ 2b ,
227
G
k
±
|x| > b,
Z Z ! Z δ δ 1 ∞ itx fnk (t)dt = e dt dFnk (x) −δ 2δ −∞ −δ Z Z ! ! Z Z δ δ 1 b 1 ≤ eitx dt dFnk (x) + eitx dt dFnk (x) 2δ −b 2δ −δ |x|≥b −δ
1 2δ
≤ αk +
1 ε ε < αk + < α + . bδ 4 2
ý < α = Fe(∞) − Fe(−∞) = 1, É Fe(x) h±Êº (6.2.10) Ç È n ¶ · »! ( ¤ < F (x) → Fe(x). ËÌ §´!Í 1 Ä! {f (t)} )*Å Fe(x) 'º »n q (6.2.8) ÎÄ f (t) (±Êº» Fe(x) 'º»n òEϧ2 l Ä Fe(x) = F (x). Ð ¡ F (x) → F (x). ÑÒ tnÓÔ F (x) 6→ F (x), ÕÖ8 Z× ¼ # ³ (ÙQ! ò ð8\0¨; § ø¼ # {F (x), k ∈ N } Ø {F (x), n ∈ N } d § ø û F (x) <ÚmÛÜÝÞº» G(x). p {F (x), k ∈ N } Ù)*Å ßà 80á Ä G(x) â(· f (t) h'º»±Êº»! ( ϧ2l ã ä ÇÈn¶· F (x) → F (x). åæ 6.2 1. çéèéêìëéíéîéïéðéñ {F (x)} òéóéôéõéöé÷éøéíéîéïéð F (x), ùéúéóéôéû x ∈ R üéýéþ 2. çéèéêÿë {F (x)} ü ñ éíéîéïéð óéô õ íéî ï ð F (x), ù F (x) éíéî þ 3. çéèé ê ñ →− →−ó ô ù →− ð ó ô þ → − 4. ë ξ n ξ → ξ , éç ξ þ 5. ñ {ξ } í î ï ð {F (x)}, ! F (x) → F (x), " {η } ó ô õ # ð C, çéèéê (1) ζ = ξ + η øéíéîéïéðéòéóéôéõ F (x − C); (2) C > 0, ù ζ = øéíéîéïéðéòéóéô õ F (Cx). 6. $ {ξ } éíéîéóé ô % ξ, $ {η } éíéîéóéô %#éð a, çéè ξ + η éíéîéóéô % Pξ + a. 7. $ {ξ } '&'(' '' ''é ñ *)+,-. −1 1 /'0'1 'ø 2'3'4éíéî þ éç η = éíéîéóé ô % U (−1, 1) þ 8. $ ξ → ξ, 5 g R 1éøéöé÷éïé ð éç g(ξ ) → g(ξ). 9. 6178 íé î 9 :; < = > 7 ? @ þ d
◦
nk
nk
d
d
n
n
nk
n
mk
d
n
1
n
n
p
n
n
d
n
n
n
n
n
n
n
n
n
ξn ηn
n
n
n
n
n
k
k=1
p
n
1
p
n
ξk 2k
A«CB
228
$éíéîéïéð
10.
F (x)
ûDéøEFéïéð lim
t→∞
EG ë
1 2t
Z
e−isy f (s)ds = F (y + 0) − F (y);
−t
Z
1 2π
çéè
f (t),
t
HI ç è
ξ
π
e−itj fξ (t)dt = P (ξ = j). −π
&(JéíéîéøHI ñ û $éíéîéïéð F (x) ûé D øEé F ïéð f (t), éç "$
11.
{ξn }
lim
c→∞
1 2c
Z
¬E®¯
|f (t)|2 dt =
ξk
x
KLMN õ1Oéø P Q þ
[F (x + 0) − F (x)]2 .
ø TT T ξ , ξ , DTXT1T7 õ ξ − ξ , YTZ T 12. çéèéû[ ü é í îéï ð F (x) \]éûD^EFéï ð f (t), û ü_ ïéð x \ h > 0 , (
RTS êUTVTWT&T(TTVTJ í î ï ð
n P
k=1
X
c −c
Sn =
F (x)
1
2
1
sin u u
2
y = 0.)
1 2h
Z
x+2h
F (y)dy −
Z
1 2h
x
1 π
F (y)dy =
Z
∞
2
u e−iux/h f ( )du. h
R SéêDX`aPQ õ F ∗ G , b G [−h, h] 1éøcdéíéîéïéð þ ) $ ξ øéíéîéê P (ξ = − ) = P (ξ = 0) = , " P (ξ = 0) = 1. e îéïéð F (x). çéèéê x
( 13.
x−2h
h
n
−∞
h
1 n
n
1 2
n
0
ξn
øéí
n
d
(1) Fn → F0 ,
14. 15.
∧
(3) d∗ (Fn , F0 ) = sup |Fn (x) − F0 (x)| 6→ 0.
(2) lim Fn (0− ) 6= F0 (0− ),
é íéîéïéðéü ñk l éç F → F f!gf d(F , F ) → 0. ëéíéîéïéð F (x) hé) øij ! í î ï ð ñ F (x) ø m miéóéôéõ F (x) ø m mib m = 1, 2, · · ·, ù F (x) → F (x). $ {p(x), p (x) : n ≥ 1} né o ïéðéñÿ ë p q ü Lebesgue ro 0 østÿû] uéð x v(w p (x) → p(x), ùéû R 1[x Borel s A üéýy $
n→∞
x
d
{F, Fn : n ≥ 1}
n
n
n
d
n
16.
n
1
n
17.
$
Z
{p(x), pn (x) : n ≥ 1}
(1)
A
pn (x)dx →
Z
p(x)dx. A
noéïéðéñ9z{ | O } ~éó ô ê
Rx Rx pn (t)dt → −∞ p(t)dt, −∞ R R
∀ x ∈ R1 ,
B , R éü p(x)dx, ýy v( R∀ RBp ∈(x)dx → p(x)dx, û ü_ B ∈ B üéý v( . b (3) í î ñ P (A) = p (x)dx ó ô õ í î P (A) = R p(x)dx. (3) ⇒ (2) ⇒ (1). çéèéê ;< (3) 2éõ p (x) roéóéôéõ p(x); 5 (2) ⇔ (1). (2)
(3)
pn (x)dx →
û[ A
s
1
A
Borel A,
n
n
A
A
A
1
n
A
n
¡ §Ì ¢C ³ {ξ , n ∈ N } ¡¢£¤¥¦§ ਩ª«¬® ¯°± S = P ξ . §6.3
n
n
n
k
k=1
(Ω, F, P )
§6.3
²C³´µ¶·C¸¬E®¯
229
¹º»¼ ½¿¾ ¡ 6.1 À ÂÁ¿Ã¿Ä ¿ ¡ Õ¿ÇÉÈ¿ÉÊ ÄÉË ÑÉÌ¿Í:´¿ÎÉÏ ¤É¥ P Ù Å ¿ » ¿ Æ ¨Ò ËÌÓÔÕÖ× ¨©ª«¬Ø ¡ÙÚÛ ÒÜ ¡ ½¾ Ô ´ Ë ·ÐÑ →0 ÑÝÞº»ßàáâÐÑCãä å Êæç Ð ¨ ÙÅèÆ Ò éCê ê é ÝÞî ï ÄØðëì ê → 0 ëì → 0, í §6.3.1
Sn −an bn
p
Sn −an bn
Sn −an bn
p
d
Sn −an bn
Sn − a n lim E exp it n→∞ bn
= 1,
∀ t ∈ R.
(6.3.1)
Ë Óà ½¾ñ Îãä å Êæòç Ð ¨ ÙÅèÆóôõÛö Û÷ø ¨ Ú èùúõ á û Ò ü ý 6.3.1 (Khintchine ¹º»¼ ) þ ©ª«¬® ÿ ξ ∈ L , Eξ = a 1
1
ÿ
éCê
à
i.i.d.(
k=1
ξ1 − a ∈ L1 , E(ξ1 − a) = 0,
íäÎ
t ∈ R,
Èn
(6.3.2)
Sn − na p → 0. n
(6.3.3)
é ê ÝÞè ¡
E exp it ξ1n−a
é
)
Sn p → a. n
fn (t) = E exp it Sn −na , n n o n on n Q fn (t) = E exp it ξkn−a = E exp it ξ1n−a .
ãä å Ê ¨
1
ÐÑ ±
{ξn , n ∈ N }
o
=1+o t n
n
t n
,
t=0
¨
Taylor
n → ∞,
à (6.3.3) ä Ò (6.3.1) ä 6.3.1 × ! ÷ ø ξ ∈ L ¯ $ Ø ¡ è ® " ¡ ãä ¨å ' # ¨ ÷æòø ç Ò Ð {a , n ∈ N }, %& → 0 ä Ô üý §6.3.2 ()*+ ½¾ ,Áà - å # . / 0 1 2 3 4 ¨ 5 6Ò é ê 3 4 å # ¡¤¥ à ¨ Ý 7 89 :;< ï => à ?@A ï Ò ü B 6.3.1 þ {ξ , n ∈ N } à ©ª«¬® S = P ξ . CD Ø ¡ ?E è ® {a , n ∈ N } F 3 ÿ E è ® {b , n ∈ N }, %& fn (t) = 1 + o
→ 1,
n → ∞,
1
Sn −an n
n
1
p
n
n
n
k
k=1
n
n
Sn − a n d → N (0, 1), bn
(6.3.4)
,
AHGCB
230
MN
lim P
n→∞
½¾ ÓO {ξ , n ∈ N } P éQR î ï ½¾ üý 6.3.2 (6.3.4) n
Sn − a n <x bn
∀ x ∈ R,
= Φ(x),
?@A ï Ò ä N & ä ¨S å ' Ô ÷ø
Sn − a n lim E exp it n→∞ bn
t2 = exp − 2
,
∀ t ∈ R.
(6.3.6)
1
2
1
= a, 0 <
2
±
Sn − na d √ → N (0, 1). nσ n o n −na fn (t) = E exp it S√ , nσ n Y
k=1
ξ1 ∈ L 2 ,
n ξk − a ξ1 − a E exp it √ = E exp it √ . nσ nσ
ξ1 − a E √ = 0, nσ
é ê ÝÞè ¡ íä&
(6.3.7)
ÿ
fn (t) =
éCê
(6.3.5)
ãä å# æçT ¨UV¨ ?@A ï âÝWXY ¨Z Ò üý 6.3.3 þ {ξ , n ∈ N } à i.i.d. ©ÉªÉ«É¬ÉÉ® ÿ[ ξ ∈ L , Eξ = σ < ∞ n
Dξ1
IHJKL
E
¨
ξ1 − a √ nσ
2
=
Dξ1 1 = , nσ 2 n
t=0 Taylor 2 ξ1 − a t2 t E exp it √ =1− +o , nσ 2n n
fn (t) =
1−
t2 +o 2n
t2 n
n
t2
→ e− 2 ,
t ∈ R,
È
n → ∞,
n → ∞,
(6.3.6), MN (6.3.7) ä Ò \ ½¾H]^ FH_`;Tãä å# ©ª«¬®¨ Khintchine aÅèÆF ?@A ï Ò bc Khintchine aÅèÆdef ïg hàijÑ ® ¨ n £ ©ª «¬¨klmno - ¤¥ ./0 ©ª«¬¨mn o (èpqr ). : 3 “ÅèÆ ” ¨ s t ¡ Ò ©ª«¬¨ k l m n o × w x y {z £ ©ª«¬ m h à u v n[oɨ[|[}ÉÒ~ Éy {ξ , n ∈ N } à i.i.d. ¨ p à[É è ¨ Bernoulli ©ÉªÉ«É¬ É , ê ; Ó¨ n ¨mn ¨cè ©
n → ∞, i× ¤¥ p. ½¾ ÓÊ Ä :; Ü ¤¥ ¯° Ë :; n
Sn n
²C³´µ¶·C¸IHJKL 231 ,û “ÐÑ ” , ¤¥ ¨ ¨ Ø ¡ î s ¨ (Ò9Ü ¡ ; Ä À ). ½Ñ¾ $ Ñ “ ” è p Ê Khintchine aÅèÆ õ ©
, ¤ ¥ ê “ ¡ ”,½y¾ ¡Ó¢ £ s ε >¨0,¤ P | − p| > ε È n→∞ Ò g ¦ í 0. "y ;¥ ê ãä å # æ å ç # T ¨¨ ©{ ª? «@ ¬A ® ï ½Ã ¾ × ¾ ¨! « " i å[¨ # § “¨ © ” t ¾®:¯ÓE Ø ã¡ ä A ¨ ÙÚÛ ª ¨ $ 12 i E° å ¬[ Ôi ¾ ¯° i F È ± ê 12 ¾ ² U ¡ï 6.3.3 £ "õ ï à ÐÑC Ü 34 å # Ò ê :; ½H ¡ ³ ,´ ;µ ⶷¸ Ò ¹ 6.3.1 C[D {ξ , n ∈ N } à[; ® i.i.d. ¨ 0 < p < 1 à[Éè ¨ Bernoulli © ª«¬Ò S = P ξ P å # B(n; p). Ü Ù º ¡ » p = 0.4 à · ½¾ å W ¼ n = 5, n = 10 F n = 20 S ¨ “½¾¿ ”, N ÀÁ ¨  ¾jà S = k ¨ ¤ §6.3
Sn n
S√ n −na nσ
n
n
k
n
k=1
¥ o
n
n
ÄÅÆÇÈ
6.1
½¾ Ü n Å “½¾¿ ” ÓÉ Ü § ÅËÊÌÍ # ¨ Ý Ò C D ½¾¢ S 12 E ÏyÐ Â ÓÑ 0 Ó ê 1234å# ¨ ½¾è¿ ZÒ ¹ 6.3.2 C D {ξ , n ∈ N } à ; ® i.i.d. ¨ P n ¬Ò ½¾ p (x) jà S = P ξ ¨ ½¾è Ò $Ô k n
n
n
n
n
k
k=1
p1 (x) =
(
1,
0 < x < 1;
p2 (x) =
0, x ≤ 0, x ≥ 1.
p3 (x) =
1 2 2x , 1 2 1 2
2
2
x − 3(x − 1) 2
2
,
x − 3(x − 1) − 3(x − 2) 0,
ÄÅÆÇÈ
6.2
2
¨ Î Ò í : 3 34å Å õÒT¯° n
Ó å # "
U (0, 1)
¨©ª«
x,
0 < x < 1;
2 − x,
1 ≤ x < 2;
0
x ≤ 0, x ≥ 2.
x ≤ 0;
,
1 ≤ x < 2;
2 ≤ x < 3;
x ≤ 0, x ≥ 3.
ÅÖ¿ Z Ó ê 34å# ¨ ½¾è¿ ZÒ z× $ Ø å# ¨ i.i.d. ¨ ©ª«¬® Ö Ôi ÙÚ Û ï 6.3.3 Ü Ö P Ý Û÷ø Öy 12 EÝ° å F Ý å #Þ n → ∞ È « Ø Ý@A î ß Ò é Õ½¾¿ ´ "Ö
n
S√ n −na nσ
àHGá IHJKL
232
âãäåæçèéêë()*+ üý ì í î ï Ø ð # æ ç T Ý Ü ? @ A Û ï 6.3.3, $ Ø ð # öø÷ T ù ú ù Ý û üý Þ þ ñ ÿ , û Ûü g Ø ð # Ý Ö þ ñ Ü ¯EÝAÝ t Ö ¡ ùi ñ ;µy! $ {ξ , n ∈ N } ; ú%îï Ý Ö §6.3.3
ñóò í ô õ 0 Þ î ï : × öø÷ T Ý Ü ? @ A Ý ® Ý"# ü
n
Eξn = an ,
&
Sn =
þ ñ ' û() EÝ° ðF
0 < Dξn = σn2 < ∞, n X
ξk ,
Bn2 = DSn =
k=1
∀ n ∈ N. n X
(6.3.8)
σk2 .
(6.3.9)
k=1
n
X ξk − a k Sn − ESn √ = Bn DSn k=1
* ð+,-.()/0 N (0, 1) Ý ü 1B 6.3.2 C D î ï 5 τ > 0,
{ξn , n ∈ N }
Ù Ú
(6.3.8),
n 1 X E (ξk − ak )2 I(|ξk − ak | ≥ τ Bn ) = 0, 2 n→∞ Bn
lim
678 Ù Ú Linderberg ü þ ñ ' ð9:; Linderberg Ý s< ü 1= 6.3.4 >? {ξ , n ∈ N } ÙÚ @ ØABïC
234 (6.3.10)
k=1
n
Linderberg
Ö 6 > ;
ξk − a k p → 0, max 1≤k≤n Bn lim max
n→∞ 1≤k≤n
yHÜ
D 7E Feller ü F G CIHJ (6.3.11) Dü JLK (6.3.12)
σk2 = 0, Bn2
MNDA ÝO Ö P
Chebyshev ξk − a k P max ≥ τ = P max |ξk − ak | ≥ τ Bn 1≤k≤n 1≤k≤n Bn
(6.3.11) (6.3.12)
QSRTUVLWSXYLZS[\
§6.3
=P
n [
k=1
=
n X k=1
=
]L
(|ξk − ak | ≥ τ Bn )
!
EI (|ξk − ak | ≥ τ Bn ) ≤
≤
n X k=1
n X k=1
E
P (|ξk − ak | ≥ τ Bn )
ξk − a k Bn τ
2
I (|ξk − ak | ≥ τ Bn )
n 1 X E (ξk − ak )2 I(|ξk − ak | ≥ τ Bn ) , 2 2 τ Bn k=1
DBïü 5 0 < τ < 1, þ ñ (6.3.12) Dü 4
³ J
(6.3.10)
max
1≤k≤n
=
233
D^
(6.3.11)
σk2 1 = 2 max E(ξk − ak )2 Bn2 Bn 1≤k≤n
1 max E (ξk − ak )2 I(|ξk − ak | < τ Bn ) + E (ξk − ak )2 I(|ξk − ak | ≥ τ Bn ) 2 Bn 1≤k≤n n X ≤ τ2 + E (ξk − ak )2 I(|ξk − ak | ≥ τ Bn ) .
Þ DHÜ § n → ∞, ³ § τ ↓ 0, _P (6.3.12) Dü ` 6.3.2 (6.3.11) Dab þ ñ Öc>?>?îï {ξ , n ∈ N } ÙÚ Ö de Þ / 6f° ðgHÜSh Ý ij n → ∞ Linderberg kml mn MÚmo[ü þ ñ ^mo[Öp>?m: m ýqmr.mst n Í Ý muv Ý « Øw x Öyd[mz Ü Ý mmm (m|{} ) ~mmm/m0[ðm+[ü ·m>mCy [Ým[Ý ðm+
Ý Â Ý ð+ j Ý ð+NN ü ì í e Ý w x (j n → ∞ ÿ ù ()/0 k ) l n MÚoÖSd õ ÖS/ 6f ðg ð+ü ÿ Linderberg Ý < Þ ü 6.3.1 >?îï {ξ , n ∈ N } ÙÚ Linderberg Ö 6 k=1
n
S√ n −ESn DSn
n
FG CIÖ S
D ÿ
lim Bn = ∞ .
(6.3.11)
1 max |ξk Bn 1≤k≤n
∀ ω ∈ Ω,
(6.3.13)
n→∞
max |ξk (ω) − ak |
p
Ý Ö ]
− ak | → 0, (6.3.11)
DBïAÖ í
D Bïü ; îï Ý ÜSÛü 1= 6.3.5 (Linderberg mm m¡ 1m= ) >m?[î[ï mmm m Ù Ú Linderberg Ö 6 1≤k≤n
(6.3.13)
Sn − ESn d → N (0, 1) . Bn
{ξn , n ∈ N }
(6.3.14)
234
àL¢á YLZS[\
FG C þ ñ£
ð¤¥
Sn −ESn Bn
ݦ§(ξ ¨−© a& ),E 1 Bn
ξnk =
g
ξnk
k
23ªAÖ
D fE
(6.3.10)
«¬ ¦§¨© Þ
lim
n→∞
n X
t=0
fnk (t) = 1 −
zHÜ
rnk (t) = o
σk2 2 ; Bn
∀ n ∈ N.
g
fnk (t). n Q fn (t) = fnk (t). k=1
2 E ξnk I(|ξnk | ≥ τ ) = 0,
Ý
k=1
fn (t)
2 Eξnk =
Eξnk = 0,
6
k = 1, · · · , n;
k
Taylor
σk2 t2 2 2Bn
®¯Dg
,
(6.3.13)
k = 1, · · · , n,
(6.3.15)
DÖ 4 5
k = 1, · · · , n,
+ rnk (t),
σk2 t2 Bn2
∀ τ > 0.
t ∈ R,
þ ñ
n → ∞,
n → ∞.
° LS r (t) ±MúØÖ} M> i.i.d. ö÷ h ' d²³Ö þ ñ ´µ¶ ·ñ Ý ¸ü ¹ iº»¼º½¾ Ü Ý >;MNDC nk
itx e − 1 − itx −
þ ñ P.
t2 x 2 2
≤ t2 x2 ∧ |tx|3 ,
2 σk2 t2 t2 ξnk itξnk |rnk (t)| = fnk (t) − 1 − = E e − 1 − itξnk − 2 2Bn 2 2 2 t ξnk 2 ≤ E eitξnk − 1 − itξnk − ≤ E t2 ξnk ∧ |tξnk |3 . 2
(6.3.11) D^ Ö 4 5À¿ Û Ý t AÖ
p
tξnk → 0,
4 5
τ > 0,
n
Á ðÂ
2 E t2 ξnk ∧ |tξnk |3 ≤ E |tξnk |3 I(|ξnk | < τ ) + E (tξnk )2 I(|ξnk | ≥ τ ) σ2 ≤ τ |t|3 k2 + t2 E (ξnk )2 I(|ξnk | ≥ τ ) . Bn
u ª n X k=1
n n n X X X σk2 t2 σk2 3 |rnk (t)| = f (t) − 1 − ≤ τ |t| + t2 E (ξnk )2 I(|ξnk | ≥ τ ) nk 2 2 2Bn Bn
= τ |t|3 +
Þ DHÜ £
k=1
k=1
n X
k=1
t2 E (ξnk )2 I(|ξnk | ≥ τ ) .
n → ∞, n X
k=1
k=1
à £
_P
τ ↓ 0, n 2 2 X fnk (t) − 1 − σk t → 0, |rnk (t)| = 2Bn2 k=1
∀ t ∈ R.
QSRTUVLWSXYLZS[\ 235 Ä í |f (t)| ≤ 1, k (6.3.12) DÖc:Å © t g ÁðÂ Ý n, þ ñ 0 < < 1, k = 1, · · · , n. ¹ i :Å |u | ≤ 1, |v | ≤ 1 Bï Ý Æ N M ND
§6.3
nk
σk2 t2 2 2Bn
k
n n n Y Y X uk − vk ≤ |uk − vk |,
þ ñ P.
k
k=1
k=1
(6.3.16)
k=1
n n n Y 2 2 Y X σk2 t2 fnk (t) − 1 − σk t = 0. lim fnk (t) − 1− ≤ lim n→∞ 2Bn2 n→∞ 2Bn2 k=1
k=1
k=1
lim fn (t) = lim
n→∞
n→∞
k «¬ÇÈÉ ÛÊ E J
n Y
fnk (t) = lim
k=1
(6.3.14),
lim
n→∞
n Y
k=1
1−
: Ê þ ñ P . Î : Ê S
σ 2 t2 1− k 2 2Bn
(6.3.12)
þ ñÑ
n 2 2 X σ
k=1
n Y
k=1
n,
t2
= e− 2 ,
þ ñ
ex(1−x) ≤ 1 + x ≤ ex ,
n Y
k=1
þ ñËÌ JLK
σk2 t2 2Bn2
S :Å © t g ÁðÂ Ý i Í J Ý MND
n→∞
k Bn2
t2
(
n t2 X σk2 ≤ exp − 2 Bn2
DÏÐ
k=1
k=1
1−
k=1
.
∀ t ∈ R. 0<
σk2 t2 2 2Bn
(6.3.17)
< 1, k = 1, · · · , n,
¹
|x| < 1, )
t2
= e− 2 ,
n X σk2 σ2 = max k2 → 0, 2 1≤k≤n 1≤k≤n Bn Bn
≤ max
σk2 t2 2Bn2
∀ t ∈ R.
n → ∞,
!2 n n t2 X σk2 t4 X σk2 ≥ exp − − 2 B2 4 B2 k=1 n k=1 n !2 n t4 X σk2 t2 · exp − → e− 2 , n → ∞, ∀ t ∈ R. 2 4 Bn
σ 2 t2 1− k 2 2Bn
= e− 2
n Y
k=1
Ò ÷ ÓÔ Ê _P (6.3.18) DÊ ÕJÖü Linderberg M Í× JÊ Ø i h ' MÙ ~Ê ; iÚÛ ?ü
Ô Í Ø
236
1=
{Ln , n ∈ N },
6
$
6.3.6
ØP
Ü ¢SÝ L L Y ZS[\ E ø n ∈ N} î ï ÞÞÞ Þ Ê >Þ?ÞßÞàÞ/ ÚÞá © Þ
{ξn ,
max |ξk | ≤ Ln ,
(6.3.14) DBïü FG C S max |ξ | ≤ L ÏÐ k
1≤k≤n
k
Ln = 0, Bn
lim
n→∞
1≤k≤n
(6.3.18)
n
max |ak | = max |Eξk | ≤ max E|ξk | ≤ Ln ,
1≤k≤n
lim Ln n→∞ Bn
=0
1≤k≤n
1≤k≤n
max |ξk − ak | ≤ 2Ln .
^
1≤k≤n
lim
sup max |ξk (ω) − ak |
ω∈Ω 1≤k≤n
= 0.
ÿâ KSÊ 4 5 τ > 0, Ë n ÁðÂÊ ÿ u k ªA (|ξ − a | > τ B ) = {ω | |ξ (ω) − a | > τ B } = Φ, Bn
n→∞
k
k
n
1 2 Bn
k
n P
k
n
k = 1, · · · , n .
E (ξk − ak )2 I(|ξk − ak | ≥ τ Bn ) = 0,
Bï Õ 6.3.5 ^ (6.3.14) DBïü 1= 6.3.7 (Lyapunov 1= ) $ {ξ , n ∈ N } E îï Ê >?ß à δ > 0, ØP X
]
k=1
Linderberg
n
6
lim
D Bïü
FG C S à (|ξ
n→∞
(6.3.14)
n
1
Bn2+δ
(6.3.19) k
7E
k=1
E|ξk − ak |2+δ = 0,
Lyapunov
− ak | ≥ τ Bn )
ü
|ξk − ak |δ ≥1, |τ Bn |δ
Ê ¹ i L J K
Chebyshev
MND Ú O Ê þ ñ P
E (ξk − ak )2 I(|ξk − ak | ≥ τ Bn ) ≤
ã: ' Ê þ ñÿ
1 E |ξk − ak |2+δ I(|ξk − ak | ≥ τ Bn ) . δ |τ Bn |
n 1 X E (ξk − ak )2 I(|ξk − ak | ≥ τ Bn ) 2 n→∞ Bn
lim
k=1
]
(6.3.19)
≤ lim
1
n X
2+δ n→∞ Bn k=1
Linderberg
E |ξk − ak |2+δ I(|ξk − ak | ≥ τ Bn ) = 0,
BïÊ Õ
6.3.5
^
(6.3.14)
DBïü
QSRTUVLWSXYLZS[\ 237 éSê g k − 1 ëê ü ò ä 6.3.3 $ : LåSæ Ê à º k åSæLçSè 1 L ì n åSæLç ±í: ê Ê ζ âî í Ú n ê ç L Ú éSê © ü JLK §6.3
n
ζn − Eζn d √ → N (0, 1). Dζn
mF G ïC >mðmñ 6.1.5 dmãmÊ þ ñ Õ <mmmm ξ E Cò>m? òIº k å}æ|ç í |é ê Ê ÿm£ ξ = 1; >m?mí mëmê Ê ÿm£ ξ = 0. m {ξ } : úm%[î[ï Ú Bernoulli óÊ 23 ξ ô ©E p = Ú Bernoulli ð+ü Ä í ζ = P ξ , 23 |ξ | ≤ 1, ∀ k ∈ N . þ ñ í L ≡ 1, S k
k
k
k
k
n
1 k
k
n
k
k=1
k
n
n P
lim
k
n→∞ k=1
Dξk =
1 k
−
1 k2 ,
1 k
n P
Dζn = Bn2 =
n P
1 2 n→∞ k=1 k
= ∞,
lim
Dξk =
n P
1 k
< ∞,
−
(6.3.18) BïÊ ]L Õ 6.3.6 PJ Û ûü ä 6.3.4 $ {ξ , n ∈ N } E î ï õ õõ õ Êöz ç JLKSªA (6.3.14) DBïü Fù 1: ú Íû P k=1
k=1
n P
k=1
ξn
n
Ñ üý . P Û ûü Fù
n P
k=1
ak = Eξk = 0,
]Ë í þ ñ 2: í δ = 2, |ξk | ≤
√ k,
E|ξk − ak |2+δ
Dξk = Eξk2 = k3 ,
Bn2 =
n P
k=1
Ln =
√
k 3
n,
=
n P 1 E|ξk lim 2+δ n→∞ Bn k=1
n → ∞,
õõ÷õø ðõ+
n(n−1) . 6
d ÿ
→ ∞,
√ √ U (− n, n).
∀ k ∈ N,
(6.3.18)
BïÊ Õ
6.3.6
_
k
2 Bn2+δ = Bn4 = n(n−1) . 6 √ n n R P P 1 k √ √ x4 dx = = Eξk4 = 2 k − k k=1
1 k2
k=1
1 30 n(n
6(2n+1) n→∞ 5n(n+1)
− ak |2+δ = lim
+ 1)(2n + 1),
= 0,
_ Lyapunov B ïÊ Õ 6.3.7 PJ Û ûü 1= ë §6.3.4 þÿ ¡ H ûîïðð+ ö÷ ; Ú ç ÕüSàÕ 6.3.3 ç Ê þ ñ L C J K ÿ i.i.d. {ξ , n ∈ N }, Ë ξ f Ê 23ßà Ú @ Ê (6.3.7) DBïü ÊSÚ Ó 2 M îïðð+ ö÷ ; ç ÕÊS_Õ < 6.3.1 ç Ú (6.3.4) DBï Áð ü n
1
238
1 ö Ê >?
6.3.3
$
F (x)
E ð+ ¨© Ê
ÜL¢SÝ L Y ZS[\ 7 F (x) /0
F (x) = 1 − F (x).
x2 F (x) =0. u2 dF (u) −x
lim R x
x→∞
(6.3.20)
à ªÊ þ ñ MJLK >; Û ûC 1= 6.3.8 $ {ξ , n ∈ N } E i.i.d. Ê 6 ç ÕÊ _ßà ç f© {a , n ∈ N } g/ 6f© {ξ , n ∈ N } ØPÕ < 6.3.1 ç Ú (6.3.4) D Bï Ú Áð C ξ Ú ð+ ¨© F (x) /0 ö ü ; û î ïMð ð+ öø÷ Ú ; Ú ç °Õ ü Ú : â ¾ þ ñ ^oÊ Lin- derberg DÚ Bï Á ð ü Ê >; ñ K Linderberg
2M (6.3.14)(6.3.14) DB ü ä 6.3.5 $ {ξ , n ∈ N } E õõõ õ Êöz ç ξ õõ/õ0õ+ N (0, ). B = P . þ & Ú ¦§¨©E f (t). Í ^Ê n
n
n
1
n n
2 n
° Ê
k=1
n
Sn Bn
1 2k
n
n t2 1 Y 2k fn (t) = exp − P n 2 1 k=1 2k k=1
n→∞
AÊ
Sn −ESn Bn σ12 2 Bn
1 2n
=
= exp
Sn Bn
n P
1 2k
t2 k=1 t2 = e− 2 , ∞ P 2 1 2k −
k=1
d
→ N (0, 1).
1
2 = P n
→ 12 .
MBÊ SLS Õ 6.3.4 â KSÊ >? Linderberg Bü Linderberg MBü Feller E Ê {ξ , n ∈ N } = a , 0 < Dξ = σ < ∞, ∀ k ∈ N . 6 (6.3.14) Dg Feller ðAB Ú Á & S = P ξ , B Eξ P = Dξ .
Linderberg Bü FG CIÕ 6.3.4 gÕ 6.3.5 JLK Linderberg (6.3.14) Dg Feller ðAB Ú Á Ê ËÌ JLKS É ü ðABÊ!"# i Õ 6.3.5 JLK$% ç ýÚà&'$ ( (6.3.14) D g Feller & 4 ý íÕ t ∈ R. à º)¼ ¦§¨© : ¾ ç Ê* SJ
DÊ _ 6 BÊ 1= 6.3.9 $
k=1
(6.3.12)
n
n
k
k=1
1 2k
Feller
n
2 n
k n
k
k
2 k
k
k=1
|fnk (t) − 1| ≤ 2E(1 ∧ |tξnk |),
SQ RTUVLWSXYLZS[\ 4 5 ε > 0, * |f (t) − 1| ≤ 2EI(|ξ | ≥ ε) + 2E|tξ + Chebyshev MND^ §6.3
nk
nk
4 5
ε > 0,
nk |I(|ξnk |
P (|ξnk | ≥ ε) ≤
max |fnk (t) − 1| ≤
1≤k≤n
àD ç Ê H £
239
à £
n → ∞,
ε ↓ 0,
+
< ε) ≤ 2P (|ξnk | ≥ ε) + 2|t|ε.
2 Eξnk 1 σ22 = . ε2 ε2 Bn2
(6.3.21)
2 σ22 max + 2|t|ε. ε2 1≤k≤n Bn2 Feller
_P
max |fnk (t) − 1| → 0.
Î : Ê ¹ i M ND
(6.3.22)
1≤k≤n
|eix − 1 − ix| ≤ x2 ,
,
σ2 2 |fnk (t) − 1| = E eitξnk − 1 − itξnk ≤ E eitξnk − 1 − itξnk ≤ t2 Eξnk , = t2 22 , Bn
-
(6.3.22)
n P
DÊ _P
k=1
n X k=1
|fnk (t) − 1| ≤ t2 .
|fnk (t) − 1|2 ≤ max |fnk (t) − 1| 1≤k≤n
≤ t2 max |fnk (t) − 1| → 0.
n X k=1
|fnk (t) − 1| (6.3.23)
1≤k≤n
+. © |z| ≤ 1 AÊ |Re z| ≤ 1, _ / ] u = exp {f (t) − 1} g v = f k
nk
k
|e | = |e i (t) 0 M ND (6.3.16), P. Re z − 1 ≤ 0,
nk
z−1
Re z−1
| ≤ 1,
( n ) n n X X Y (fnk (t) − 1) − fnk (t) ≤ |exp {fnk (t) − 1} − fnk (t)| . (6.3.24) exp
+
ez
Ú
k=1
k=1
Taylor
k=1
®¯D
ez = 1 + z +
PÊ
|z| ≤
1 2
AÊ |ez − 1 − z| ≤
∞ X zn n! n=2
∞ ∞ X X |z|n |z|n−2 = |z|2 ≤ |z|2 . n! n! n=2 n=2
240
+ (6.3.22) Dm^mÊ Ë n 1Á mÂmÊ32 D^Ê n → ∞ AÊ
|fnk (t) − 1| ≤
1 2
ÜL¢SÝ L Y ZS[\ + (6.3.23) Dmg (6.3.24) , m
( n ) n X Y (fnk (t) − 1) − fnk (t) exp k=1
≤
≤
n X
k=1 n X
¥D4 (6.3.14) D Û5 Ê 2P lim exp
n→∞
k
üý ./ ©
z,
(
n X k=1
|exp {fnk (t) − 1} − 1 − (fnk (t) − 1)| |fnk (t) − 1|2 → 0.
(fnk (t) − 1)
k=1
|ez | = eRe z , n→∞
D_ E lim
n→∞
t = 1,
n X k=1
n X k=1
lim
* ^o 1 − cos x = 2 sin P |x| > τ AÊ 2 sin
t2
fnk (t) = e− 2 ,
n X k=1
∀ t ∈ R,
k=1
Re (fnk (t) − 1) = −
t2 , 2
ξ2 E cos ξnk − 1 + nk 2
lim
n→∞
n Y
∀ t ∈ R.
àDÔ6í © Ê _P
2 x x2 2 ≤ 2 , 2 x x2 2 <δ 2 ,
n→∞
= lim
∀ t ∈ R.
t2 2 E cos tξnk − 1 + ξnk = 0, 2
n→∞
¥ 8 D4
)
( n ) X t2 lim exp (fnk (t) − 1) = e− 2 , n→∞ lim
¦ ¤Ê
k=1
k=1
2u 3 4 5 ª
τ > 0,
∀ t ∈ R.
= 0.
ßà
(6.3.25) 0 < δ = δ(τ ) < 1,
2 2 ξnk ξnk E cos ξnk − 1 + ≥E cos ξnk − 1 + I(|ξnk | > τ ) 2 2 1−δ 2 ≥ E ξnk I(|ξnk | > τ ) . 2
(6.3.25) n X
E
D Û 5 Ê _P
2 ξnk I(|ξnk |
n 2 X 2 ξnk lim E cos ξnk − 1 + = 0, > τ) ≤ 1 − δ n→∞ 2
ª_ (6.3.15) DÊ Linderberg B ( k=1
k=1
Ø
QSRTUVLWSXYLZS[\ 241 1= §6.3.5 789:;< ¡ ©=> ¶ Ú st?@ ç áÌ AB À{ * +,-./0+ ÚC à DE( ºE) ¼ Õ = 5.4.7 * ^ o Ê n F { →−ξ n G / 0E + 5 n FÞ { →−s , η = →−s →−ξ Þ 1 GÞ/Þ0IÞ+ − N (→ a , B), Þ3IHÞÞÞ4 + J Ê JLKSC − − − − N (→ s → a, → s B→ s ). ª 1= 6.3.10 $ →−ξ E n F L{S Ê >?4 5KL ||→−s || = 1 Ú n F {S →−s , §6.3
τ
τ
τ
n
→ − d → − s τ ξn → N (0, 1),
6
→ − d → − ξn → N ( 0 , I).
Õ = Ê tGM 5 ; Ú ç = 2 fE :GM 5 ; Ú ç Õ Õ = Ê u k P N ~ ( OP 6.3 1. QSRSTSUSVSWSXSY[Z[\S][^[_[`[aSb[c[d[e[fSg 2. QSRSTSUSVSWShi`[aSb[][^[j λ → ∞ kShilSdSmSnS]S^Sg 3. o ξ pSqSrSs ]S^StSu[v[w[x[y[hiz[][^[][{[|[} (1) [−a, a] ~SSS]S^S (2) S ` aSb ]S^S (3) Γ− ]i^hi P (ξ − Eξ ) j
n
ηn =
S
S
j=1 q P
j
j
n j=1
.
Dξj
S_ RSTSUSVShiS n → ∞ kS_SSSg 4. o {ξ } pSSSqSr _StSu[vSw[x[y[hi[[ N (0, 1), X √ n(ξ + · · · + ξ ) ξ + ··· + ξ η = ζ = p ηn
j
n
1
n
n
ξ12 + · · · + ξn2
1
n
ξ12 + · · · + ξn2
lSdSmSnS]S^ N (0, 1). √ 5. {ξ } | qr tuvwxyhi n ≥ 1, ξ ]^} (1) P (ξ = ± n) = 1/2; (2) P (ξ = 0) = 1/3, P (ξ = ±n ) = 1/3, (α > 0). [X Lyapunov [ p[ r P 6. QSSSSSfSSX[Y[}ij n → ∞ kSh e n /k! → . 7. {ξ } | qSr tSuSvSwSxSy[h][{S[ [ ]S^[} n
n
n
n
n
α
−n
n
k=0
k
1 2
n
P {ξn = ±n} =
1 , 2n2
P {ξn = 0} = 1 −
1 , n2
n ∈ N.
XSYS} {ξ } S¡S¢SSSSSe[fSg n £¤¦¥Shi§S¨ k £¤¦¥S 1 £©¦ªS« k − 1 £S¬SªSh k = 1, 2, · · · , n. (1) SS®S¥SS]S{S¯S° 1 ªSh3± ξ ² °S³S_©¦ªS´SVSh3XSY {ξ } lSdSmSnS]S^Sg S¼ _Sg¸± η ² S¼ ´S½SVSh (2) SS®S¥S Sµ¶¦· ¯S° 2 ªSh¸o 2 ªS¹©¦ºS»S| XSY {η } p lSdSmSnS]S^S_[g n
8.
n
n
n
n
242
ÜL¢SÝ ¾À¿ÁÂ
X
ÃShiÄ Feller SSÅSÆSÇS} B → ∞ È → 0. 10. {ξ } | q[r t[u[v[w[x[y[hi®[£ ξ N (0, σ ) ][^[hiz[ σ = 1, nB . X {ξ } ¡S¢SSSSSeSfSÉ[ [¡[¢ Feller SSg 9.
2 σn 2 Bn
2 n
(6.3.12) n
2 n
n
2 n−1
2 1
n > 1, σn2 =
n
Ê Ë Ì ÚÖ× ( * a.s. ÍÎ2ÏÐÑ"ÍÎÊ a.s. ÏÒÓÔÕ almost sure àÕ = 6.1.4 ÚØÀÙ ç iÚ $ÛÍÎ É ÊÜàÝÞßàá ( §6.4.1 a.s. âã<äå æ Þç a.s. ÍÎ Ú Õè ( é 6.4.1 êëìíî ξ ïëìíîðñ {ξ , n ∈ N } Õèàðòóôõö ÷ (Ω, F, P ) Êøù §6.4
a.s.
n
n o P ω lim ξn (ω) = ξ(ω) = 1,
2 ú {ξ }a.s. ÍÎ Ú ξ, ûü ξ → ξ a.s. +.ýL¿ Õ Ú ω ÞúÊ {ξ (ω)} 2Ï © ñÊþªÿ ý ε > 0, ßà k ∈ N , Ø Ë Ý n ≥ k, 2
(6.4.1)
n→∞
n
n
n
þªÊ* Ú P
∞ \ ∞ \ [
ε>0 k=1 n=k
ç Ú (6.4.2)
(|ξn − ξ| < ε)
ε>0
0 ý = Ê
(6.4.1)
=P
∞ \ ∞ \ [
ε>0 k=1 n=k
∞ [ ∞ \ ∞ \
.
m=1 k=1 n=k
(6.4.3) P
∞ \ ∞ [ ∞ [
m=1 k=1 n=k
(6.4.4)
âî ü
P
{ω | |ξn (ω) − ξ(ω)| < ε }
k=1 n=k
!
=1. (6.4.2)
1 |ξn − ξ| < m
!
= 1.
(6.4.3)
1 |ξn − ξ| ≥ m
!
= 0.
(6.4.4)
Ê!H ∞ [ ∞ \
2Ï
|ξn (ω) − ξ(ω)| < ε .
ÏñÊÏ × üø Ú
T
P
"Ê
!
lim ξn (ω) = ξ(ω),
n→∞
1 |ξn − ξ| ≥ m
!
= 0,
∀ m ∈ N.
$" # % & '!H §6.4 a.s.
P
üýÚ
243
∞ [ ∞ \
k=1 n=k
(|ξn − ξ| ≥ ε)
∞ S
!
(|ξn − ξ| ≥ ε) ,
k∈N
Ï( Ú) ðñ'ÿ + ôõ Ú &*+, ' n=k
∞ [
lim P
k→∞
n=k
∀ ε > 0.
= 0,
(|ξn − ξ| ≥ ε)
(6.4.5)
!
(6.4.5)
.
∀ ε > 0.
= 0,
(6.4.6)
-. &/ àá'* Ú é0 6.4.1 øùëìíî ξ ïëìíîðñ {ξ , n ∈ N } 1è23òóôõ ö ÷ (Ω, F, P ) & '4 ξ → ξ a.s. 567Ý8 Ï (6.4.6) ( + 1 = 6.4.1 9 Ú :; 6.4.1 øù ξ → ξ a.s., 47 ξ → ξ . <= +. S (|ξ − ξ| ≥ ε) ⊂ (|ξ − ξ| ≥ ε) , >? Ý@ôõÍÎ51èBA$5 (6.1.1) 4 (6.4.6) NBC$D'9 . á ( ý. L ÍÎ4 a.s. ÍÎ'*E F P 6.4.5 L ÍÎ4 a.s. ÍÎG HIJ K BL 6.1.7 A$5ëìíîðñ {ξ , n ∈ N } ï ξ ≡ 0, M ØÀÙ '2NO n
n
p
n
n
∞
n
n
n=k
r
r
n
þ P Þ5
lim ξn (ω) = 0 = ξ(ω), L1
n
n
n
9
? Ý
∀ ω ∈ Ω,
ØÀÙ ξ 6→ ξ, ÿ a.s. ÍÎ HI L ÍÎ JTU ξ → ξ a.s., ÏQEBR$S LV ø W 6.4.1 X (Ω, F, P ) YüZ ÷ (0, 1) & 5Ð [ ôõö ÷ '\1è ξ ≡ 0, ] ξ =I <ω< , 2 ≤n<2 , ∀ m ∈ N. M^ ç' ý r > 0, E|ξ − ξ| = E|ξ | → 0, ÿ ξ → ξ. Ï' ω Ï_`'Nabcdó n e ξ (ω) = 1, ÿ n→∞
n−2m 2m
r
n+1−2m 2m
m
n
m+1
r
n
r
n
Lr
n
ξn 6→ ξ a.s..
P {ω | ξn (ω) 6→ ξ(ω) } = 1 ,
-f. QfEf2fgfhfifjfkflïfgflmAn5àáf'ff2ëìíîðñf5foÛÍÎ , p ÷ qørs HIu 1 . L ÍÎt a.s. ÍÎG ◦
r
vBw$x À ¾ ¿ÁÂ HI @ôõÍÎ u Ï@ôõÍÎ HI L Í Îï 2 . L ÍÎt a.s. ÍÎ u a.s. ÍÎ HI @yzÍÎ u Ï@yzÍÎ HI @ôõÍÎ u 3 . @ôõÍÎ ý{|} 5ëìíî' ξ → C ⇐⇒ ξ → C. 4 . §6.4.2 ~ 2æ ) ðñ5bd
fïJëìíîf5 a.s. ÍÎ p ÷ q5rfs J Q E Þbd
5ô é 6.4.2 ê {A , n ∈ N } Ï1ô1õ1ö ÷ (Ω, F, P ) A51ò1ñ ) ' ø1ù2b dó n, e ω ∈ A , QE ) ðñ {A } bd
'û {A , i.o.}. &/ 1èBA$5 i.o. ÏÒ ÔÕ infinitely often 5 Ö× J r {) ðñ5bd
'QE é0 6.4.2 øù {A , n ∈ N } Ïôõö ÷ (Ω, F, P ) A$5òñ ) '4 244
◦
r
r
◦
p
◦
d
n
n
n
n
n
n
n
{An , i.o.} =
∞ [ ∞ \
An .
(6.4.7)
<= ' ω ∈ {A , i.o.} ⇐⇒ 2bdó n, e ω ∈ A ⇐⇒ ý T S k ∈ N , 2 n ≥ n, e ω ∈ A ⇐⇒ ω ∈ A . ' S T A ) ðñ {A } A$cdó J &/ ôï ¡5àá'¢9 F£ 6.4.6 QE 1 . ξ → ξ a.s. ⇐⇒ P (|ξ − ξ| ≥ ε i.o.) = 0, ∀ ε > 0 ; ý¤ ó ε > 0 , P (|ξ − ξ| ≥ ε i.o.) = 1 . 2 . ξ 6→ ξ a.s. ⇐⇒ ¥ ó¦§úB¨$'2 ) ðñ5fbfdf
fïëìíîðñf5 a.s. ©ª p ÷ q5rs J ÿQE«¬®ø ¯° ôõ P (A , i.o.) = 0 ± 1 5²§ J ³0 6.4.1 (Borel-Cantelli ³0 ) ê {A , n ∈ N } ´ôõö ÷ (Ω, F, P ) A 5 ) ñ J 1 . øù X n
k=1 n=k
∞
n
∞
n
n
k=1 n=k
∞
∞
n
n
k=1 n=k
◦
n
◦
n
n
0
n
0
n
n
◦
4
∞
n=1
P (An , i.o.) = 0. 2◦ .
øù
{An , n ∈ N }
P (An ) < ∞,
(6.4.8)
´ Gµ¢5 ) ðñ'! ∞ X
n=1
P (An ) = ∞,
(6.4.9)
"$#
§6.4 a.s.
4
245
<= ¶
P (An , i.o.) = 1. (6.4.7)
ïôõ5 &*+, ! ∞ [ ∞ \
P (An , i.o.) = P
¶ {
1◦ .
(6.4.8)
HI
lim P
ÿ
An
= lim P k→∞
k=1 n=k
∞ S
An
∞ P
≤ lim
∞ [
An
n=k
!
.
(6.4.10)
P (An ) = 0,
¢·'¸¶ (6.4.10) ¢ P (A , i.o.) = 0. , ïbf»f`f5©fª ,fp ÷ 5frsff' (6.4.9) 2 . ¶$b¹º5©ª ¢·' ý k ∈ N , Q Q lim (1 − P (A )) = (1 − P (A )) = 0. ) øù {A , n ∈ N } ´ Gµ¢5 ðñ'Na ý¼½ ` m ≥ k, k→∞
(6.4.8)
n=k
k→∞ n=k
n
◦
∞
m
n
m→∞ n=k
n
P
m T
Acn
m Q
=
{ ´'¸¶ôõ5 *+, '¾ T T P A =P lim A = ý¶ _9 ∞
n=k
c n
n=k
m
P
n=k
c n
m→∞ n=k
.¿
n
n=k
∞ S
(P (Acn )) = m Q
lim
m→∞ n=k
An
= 1,
m Q
n=k
(1 − P (An )),
(1 − P (An )) =
∞ Q
n=k
(1 − P (An )) = 0.
∀ k ∈ N.
(6.4.10) '¢ P (A , i.o.) = 1. : ; 6.4.2 øù {A , n ∈ N } ´ Gµ¢5 ) ÀÁ'Â4 P (A , i.o.) = 1 5 6y7«8 ´ (6.4.9) ¢ J <= Ã6y , R$Ä JÅ Ä7« , JÆÇ P (A , i.o.) = 1, ´È P P (A ) < ∞, & É NaBJ ¶ 1_BA$5 1 9 P (A , i.o.) = 0, ÊËÌÍ'ÎÏP·7Ð (6.4.9) ¢ ³0ÓÔÕÖ §6.4.3 ÑÒ ×ØÙ ¡®5Ú«'QEÛ¬Ü /Ý ÄB¨$Þßr {à ` Ý `Á5á_ J â `ãyäBA$åæBR$S Æ 5 . ® ³0 6.4.2 ç {a , n ∈ N } × à `Á' lim a = a ∈ R, ÆÇ {b , n ∈ N } ×èé `Á'Ð lim P b = ∞, 4Ð n
n=k
n
n
n
∞
n
n=1
◦
n
n
n→∞
n
n→∞ k=1
k
n P
bk a k
lim k=1n n→∞ P
k=1
= a. bk
n
n
vBw$x êBë$ìí
246
îï 'QEÐ a1 + · · · + a n =a. n
lim
QE¬ ð & ¡5á_ÄB¨ É ß ñ Éò 5 . ® J ³0 6.4.3 (Kronecker ³0 ) ç {x , n ∈ N } × à `Á' ª ·'Ð `Á'Ð b ↑ ∞, 4»` P © n→∞
n
∞
n
n=1
xn bn
n 1 X lim xk = 0 . n→∞ bn
× ¼
(6.4.11)
k=1
<= Ãó
y0 = 0, yn =
n P
k=1
xk bk ,
{ ´B¶$»`
lim yn = lim
n→∞
ô !Ð ¶ {
{bn , n ∈ N }
1 bn
n P
HI (6.4.12)
1 bn
n P
k=1
n=1
n X xk
k=1
bk
xn bn
bn =
n−1 P k=1
n−1 1 P (bk+1 b n n→∞ k=1
©ª'
:= y ∈ R.
bk (yk − yk−1 ) = yn −
×èé `Á' ô !
k=1
{bk+1 − bk }
xk =
n→∞
∞ P
1 bn
n−1 P k=1
(6.4.12)
(bk+1 − bk )yk .
(bk+1 − bk ) ↑ ∞,
ÎÏõ¶á_
6.4.2
'
− bk )yk = lim yn = y .
lim
ÎÏÐ (6.4.11) ¢ J ö÷'ø2 Kronecker á_BA$5`Á {x , n ∈ N } ´ à `Á'øùÐú1û5 üý 5 ¼ é , J ÎÏ' ¥ ßá_þ { QEÿå`yÐ ð J P p ' Ï 5 Kolmogorov 2å`5ÿBA q« ð J 0 6.4.3 (Kolmogorov ÔfÕÖ ) ç {ξ , 1 ≤ k ≤ n} × Gµ¢5 ' n→∞
n
ó
k
Eξk = 0,
Sk =
k P
j=1
ξj ,
Eξk2 < ∞,
4þ÷5
<= QEó
|ξk | ≤ c ≤ ∞,
ε > 0,
(ε + c)2 1− P ≤P n Eξk2
Ð
max |Sk | ≥ ε
1≤k≤n
≤
k=1
An =
max |Sj | ≥ ε ;
1≤j≤n
1 ≤ k ≤ n.
n 1 X 2 Eξk . ε2 k=1
(6.4.13)
§6.4 a.s.
247
B1 = A1 = (|S1 | ≥ ε) ;
Bk =
max |Sj | < ε, |Sk | ≥ ε ,
k = 2, · · · , n.
k k !" ô A = B . # P Ð I(A ) = P I(B ) Ý P (A ) = P P (B ). $m¶ { S Ý B ? t ξ , · · · , ξ Ðfr%"& S − S ´ Ý "ÎÏ S I(B ) t S − S µ¢ J ¥' É ¬"QEÐ ξ ,···,ξ 5 P P Eξ = ES ≥ E S I(A ) = E S I(B ) . ¶ {
1≤j
B1 , B2 , · · · , Bn
n S
n
n
k
k=1
n
k
n
k
k
k
n
k=1
1
k
n
k
k=1
k+1
n
k
n
k
2 k
k=1
n
2 n
k
2 n
n
n
k=1
2 n
k
E Sn2 I(Bk ) = E (Sn − Sk + Sk )2 I(Bk ) = E (Sn − Sk )2 I(Bk ) + E Sk2 I(Bk ) ≥ E Sk2 I(Bk ) ≥ ε2 P (Bk ),
ÎÏ( ¿) / * "9+
n X
n X
Eξk2 ≥ ε2
P (Bk ) = ε2 P (An ),
P9 ¨ Kolmogorov 5,-./¢ J Æ Ç c = ∞, 4 50-.12/¢ J ç c < ∞. ö÷P·"Â234 ) "Ð |S | ≤ |S | + |ξ | ≤ ε + c, ÎÏ ð ) /* B A$5 5.y6+ k=1
k
k−1
ö÷¾ > ¶ ) +¾
Bk
k
E Sn2 I(An ) = ≤ (ε + c)2
k=1
n X
k=1
n X
n n X X E Sn2 I(Bk ) = E Sk2 I(Bk ) + E (Sn − Sk )2 I(Bk ) k=1
P (Bk ) +
k=1
n X k=1
k=1
E(Sn − Sk )2 P (Bk ).
E(Sn − Sk )2 =
n P
j=k+1
Eξj2 ≤
n P
j=1
Eξj2 = ESn2 ,
n X E Sn2 I(An ) ≤ (ε + c)2 + ESn2 P (Bk ) = (ε + c)2 + ESn2 P (An ). (6.4.14)
9
7É8 ¡"$Ð
(6.4.15)
:;
k=1
E Sn2 I(An ) = ESn2 − E Sn2 I(Acn ) ≥ ESn2 − ε2 P (Acn ) n X = Eξk2 − ε2 + ε2 P (An ). k=1
(6.4.14)
P (An ) ≥
" ½ _ Ù 9 + n P
k=1
Eξk2 − ε2
(ε + c)2 +
n P
k=1
(ε + c)2 ≥1− P . n Eξk2 − ε2 Eξk2 k=1
(6.4.15)
vBw$x êBë$ìí
248
P9 50-. J
< £
6.4
=>?@ABC {ξ } DE ξ > ξ > · · · > 0 a.s., FGH ξ → 0 ⇒ ξ 2. IJKMLNOP n, |ξ | ≤ C, Q ξ → ξ, RNSO p > 0, H ξ → ξ. P 3. = {ξ } TUVWXQYHH[Z[\[]^[>[?[@[AB[C[_`IJ[K`L p
1.
n
1
2
n
n
n
n
∞
n
=
1
lim
2
P
P
n=1
n
n→∞ n k=1 a.s. ξn → 0 ∞
bWX>?@ABC[_`cI
{ξn }
4.
n
Lp
p
→ 0 a.s.
Dξn n2
Dξk = 0.
deafghTNS[i
ε > 0,
P {|ξn | ≥ ε} < ∞.
klmJKMn Borel-Contelli opq_Mrs (1) ^tuvXw 6. NxhBC {A }, yz{BC 1 = n < n < · · ·, IJK n=1
5.
n
(1)
∞ S ∞ T
1
An =
k=1 n=k
∞ S ∞ T
nj+1 −1
S
L P P { S A } < ∞, R 7. LN>?@ABC {ξ }, H (2)
∞
P { lim An } = 0.
n
j=1
2
An ;
k=1 j=k n=nj nj+1 −1
n→∞
n=nj
n
∞ X
P
j=1
R 8.
max
nj ≤n
|ξn | ≥ ε
< ∞,
∀ ε > 0,
P {ξn → 0} = 1.
L
{ξn }
TWX>?@ABC[_`\][H[Z[_M| Sn =
(1)
}~u[
[[IJ[K pm := P
N p , IJL 9. = {c } b{C_M (2)
m
k
sn =
∞ P
k=1
n X k=1
cI
n X k=1
(ξk − Eξk ),
max
2m ≤n<2m+1
Dξk k2
ck ,
< ∞,
|ηn | ≥ ε
R
∞ P
m=1
ηn =
≤
1
k∈N
ck
k=1
k
n X ξk − Eξk k=1
X
Dξj ;
j<2m+1
pm < ∞.
bm = sup |sm+k − sm |,
Sn 0 =
Sn . n
(2m ε)2
^dfghT b = 0. 10. L {ξ } TWX>?@AB[C[_M\[][H[Z_`| ∞ P
< ∞,
k
b = inf bm , m∈N
jH
RaH
§6.5
(1) }~[u
[[I[J
249
P { max |Sm+k 0 − Sm 0 | ≥ ε} ≤ 1≤k≤n
(2)
}~sIJ[KML
∞ P
Dξk k2
k=1
< ∞,
R
Sn 0
m+n 1 X Dξk ; ε2 k2 k=m+1
1 w
§6.5
ÛQå` 6.5.1 ç {ξ , n ∈ N } × ÀÁ" S = P ξ . ÆÇ ¢¡£ } ` Á {a , n ∈ N } Ý ¼¤}¼ `Á {b , n ∈ N }, ¥¢¡ 0 < b ↑ ∞, e+ n
n
n
k
k=1
n
n
n
Sn − a n → 0 a.s. bn
(6.5.1)
¦ § {ξ } ¨ â å` gª©«¡¬®µ¢ªªª ÀÁªå`ª Û¬®ª »` a.s. ©ª®²§ §6.5.1 ¯°±²³´µ¶· a.s. ¸¹º ÆÇ {ξ , n ∈ N } × ¤ ß»¼½¾ (Ω, F, P ) ) ÀÁ"¿À þ%PÁfßÃÂÄ% ω ∈ Ω, {ξ (ω), n ∈ N } f´ à%Å Á%"#%Æ ¦ %6fÏff® Å%Ç » Å ξ (ω) ©ª® 6.5.2 Æ Ç È È3È4 Ω , Ð P (Ω ) = 1, ô þÈÈÉ ω ∈ Ω , » Å P ξ (ω) ©ª" » Å P ξ a.s. ©ª Û¬ÿÐÊ » Å a.s. ©ª®²§ ³Ë 6.5.1 ÆÇ µ¢ ÀÁ {ξ , n ∈ N } ÌÍÎ4 n
n
n
∞
n
n=1
0
∞
0
0
∞
n
n=1
n
n=1
n
¤
Eξn = 0, ∞ P
·"Ð
ξn a.s.
Ï%Ð% ó
n=1
n ∈ N;
©ª Sn =
∞ P
n=1
ξn .
%
ε > 0,
∞ X
n=1
¶ÄÎ%4
Eξn2 < ∞,
(6.5.2)
%"Ñ ¼f½%Å
(6.5.2)
m≥n→∞
Ò¢ÓÔ êBë$ìí
250 P (|Sm − Sn | ≥ ε) ≤
¥ ¨$ $B¶
Õ+
p
Sn → S.
Kolmogorov ∞ X P max
#Æ ÖÁ
k=n+1
Eξk2 → 0.
Õ+
{Snk },
|Sj − Snk | ≥ ε
≤
nk+1 ∞ ∞ 1 X X 1 X 2 2 Eξ = Eξ < ∞. j ε2 ε2 j=1 j j=n +1 k=1
Ak =
max
nk <j≤nk+1
|Sj − Snk | ≥ ε ,
áØ"
P (Ak , i.o.) = 0,
÷®"Ú "+
k ∈ N,
Borel-Cantelli
k
(6.5.3)
k
× {A , k ∈ N } µ¢34ÀÁ"×B¶ ε>0
(6.5.3)
,-.+¾
nk <j≤nk+1
ÆÇ ó Ù ¶ Û ¿
m P
Snk → S a.s. .
k=1
¤
S,
1 ε2
max
nk <j≤nk+1
|Sj − Snk | → 0 a.s. ,
k → 0,
× ÀÁ" ¤ ßÜ Å c > 0, Õ+ 6.5.2 ç {ξ , n ∈ N } µ¢ |ξ | ≤ c a.s., ∀ n ∈ N . ¿À ÆÇ P ξ a.s. ©ª" ¤ P Eξ Ý P Dξ ©ª 1 . ÆÇ Eξ = 0 (n ∈ N ) ô P Dξ = ∞, ¤ P ξ a.s. Ý 2 . ÏÐ ÛÄ 2 . ÆÇ þ É n ∈ N , Ð |ξ | ≤ c a.s., Eξ = 0, ô P Eξ = P Ý n ∈ N, Dξ = ∞, ¿ÀB¶ Kolmogorov % 0-.%6+"þÉ ε > 0 Ð ³Ë
Sn → S a.s. .
n
n
∞
◦
∞
n
n=1
◦
n=1 ∞
n
∞
n
n
n=1
∞
n
n=1
◦
n
n=1
n
∞
n
n=1
∞
2 n
n
n=1
P
max |ξn+1 + · · · + ξn+m | ≥ ε
1≤k≤m
¥ ´§"þÉ
n ∈ N, P
ÎÏ
≥1−
(ε + c)2 n+m P
k=n+1
Ð
sup |ξn+1 + · · · + ξn+m | ≥ ε k≥1
Eξk2
→ 1,
m → ∞.
=1.
Ý Ù Ä 1 . Þ À Á {ξ , n ∈ N } É ßµ¢ßà {ξ , n ∈ N }, ÚÕ +Ùå {ξ , ξ , n ∈ N } × µ¢ªþªªª× ÀÁ" ô þÁß ô n, ξ á ξ âªãªä ξe = ξ − ξ , æ´ {ξe , n ∈ N } µ¢ ÀÁ" ∞ P
ξn a.s.
n=1
◦
n
0
n
0
n
n
0
n
n
n
0
n
n
n
§6.5
251
© ª" â & ©ª"ç×B¶è$Ä 2 2 P Dξ = P Dξe < ∞. â &B¶$áØ 6.5.1 P (ξ − Eξ ) a.s. ©ª"[æ´Ð P Eξ ©ª Ë 6.5.1 (Kolmogorov é%µ%¶ %Ë ) ç {ξ , n ∈ N } × µf¢%%% À Á"¿ÀÕ+» Å P ξ a.s. ©ªê ã Î4´ Ü Å c > 0, Õ+ ¶æ
∞
∞ P
n=1 ∞
|ξen | ≤ 2c, a.s. E ξen = 0, ∞ 0 P ξn a.s. ξn a.s.
©ª"øÎÏ
∞
n
n=1
Dξen = 2Dξn , ∀ n ∈ N . ∞ P ξen a.s.
n=1
n=1 ∞
n
n=1
n
◦
n
n=1
n
n=1
n
∞
n
n=1
∞ P
1◦ .
2◦ . 3◦ .
n=1 ∞ P
n=1 ∞ P
P (|ξn | > c) < ∞; E (ξn I(|ξn | ≤ c))
©ªë
D (ξn I(|ξn | ≤ c)) < ∞.
&ì«Î4´þÉÜ Å c > 0, )íî » Å ©ª ÏÐ ÛÄì«®ï» Å P ξ a.s. ©ª" ¤ ξ → 0 a.s. , ÎÏþþÉÜ Å c > 0, ïó A = (|ξ | ≥ c), ¤ Ð P (A i.o.) = 0. ¶æ {A } × µ¢34 ÀÁ"ÎÏB¶ Borel-Cantelli áØ 1 /¢ ÆÇ ¦ ó η = ξ I(|ξ | ≤ c), ¿À Î4 1 ¨ P P n=1
∞
n
n
n=1
n
n
n
n
◦
◦
∞
×Ð
n=1
P (ξn 6= ηn ) =
n
∞
n=1
n
n
P (|ξn | > c) < ∞.
P ((ξ 6= η ), i.o.) = 0, Å Å P η a.s. ©ª$¶æ {η , n ∈ N } × Ðʵ P ÎÏB¶$» ξ a.s. ©ª» ¢ À Á"ÎÏB¶$áØ 6.5.2 Î4 2 Ý 3 /¢ Ù Äðê ã ®ð Æ¸Ç ð ðÜ Å c > 0, Õð+ î ߸» Å ¸©¸ªð ¦ ðñ¸ó η = %ò É ß 0 »%ó%ô ξ I(|ξ | ≤ c), ¿%Àm¶ÄÎ%4 1 P ((ξ 6= η ), i.o.) = 0, ÎfÏ " P ξ á P η Ð â fª%Ý%®%"õf´m¶ná%Ø 6.5.2 %"Î%4 2 Ý 3 ö%÷ Å P ξ a.s. ©ª P η a.s. ©ª"ÎÏ» n
∞
n
n=1
n
∞
n
n
n=1
◦
◦
n
n
∞
n ∞
∞
n
n=1
◦
n
n
◦
n
n=1
∞
n
n=1
◦
n
n=1
ø ù¶ú ¦ ¬®µ¢ âãä ÀÁå Å Ë 6.5.2 (Kolmogorov øù¶ú ) ç {ξ , n ∈ N } × µ¢ âãä ÀÁ" S = P ξ . ¤û Ü Å a Õ+ §6.5.2
n
∞
n
n
n=1
Sn − na → 0 a.s. n
(6.5.4)
Ò¢ÓÔ êBë$ìí
252
ê ã ì «Î4´ E|ξ | < ∞, Eξ ÏÐMü Û" ¦ ý 1
1
= a.
E|ξ1 | < ∞ ⇐⇒
∞ X
P (|ξ1 | ≥ n) < ∞.
(6.5.5)
3 à ) P" ¦ Ð P P E|ξ | = E (|ξ |I(n − 1 ≤ |ξ | < n)) ≤ nP (n − 1 ≤ |ξ | < n) = 1 + P (|ξ | ≥ n). 7É8 ¡"$Ð ∞
1
1
n=1
∞
1
n=1 ∞ P
n=1
∞
1
n=1
P (|ξ1 | ≥ n) = ≤
∞ P ∞ P
n=1 k=n ∞ P
P (k ≤ |ξ1 | < k + 1) =
∞ P
k=1
kP (k ≤ |ξ1 | < k + 1)
E (|ξ1 |I(k ≤ |ξ1 | < k + 1)) ≤ E|ξ1 |.
( ¿)íþ 8 ¡ "Ú+ (6.5.5) ÆÇ û Ü Å a, Õ+ (6.5.4) /¢"¿ÀÿÐ k=1
1
n=1
Sn n
#Æ
→ a a.s. ,
ξn Sn − Sn−1 Sn n − 1 Sn−1 = = − → 0 a.s. . n n n n n−1
¥ ÿ B¨"þÉ ε > 0, Ð P (|ξ | ≥ nε i.o.) = P ≥ ε i.o. = 0. ÆÇ ó A = (|ξ | ≥ n), ¿ªÀ {A } ´µ¢ªªª3ª4ÀÁª" ÎÏõ¶ ª) í 3 à Ý Cantelli áØ P |ξn | n
n
n
ÚÐ
n
∞
n=1
æ´B¶ $# × ÚÄB¨
¶
E|ξ1 | < ∞, Eξ1 = a,
(6.5.5)
P ∞
Borel-Cantelli
¦ ¬ÄB¨
P (ηn 6= ξn ) =
áØ n=1
∞ P
n=1
(6.5.4)
/$ó
â & × Ä
P(ηn 6= ξn , i.o.) = 0, n P 1 ηk − na → 0 a.s. n
lim Eηn = lim Eξn I(|ξn | < n) = a, n→∞
ÎÏ
k=1
≤ 2,
(6.5.4)
n 1 P Eηk n n→∞ k=1
lim
n 1X (ηk − Eηk ) → 0 a.s. n |ηn −Eηn | n
ηn = ξn I(|ξn | <
P (|ξn | ≥ n) < ∞,
k=1
n→∞
Borel-
P (|ξ1 | ≥ n) < ∞,
E|ξ1 | < ∞.
n), n ∈ N ,
ö÷¾
n
n E ηn −Eη = 0, n
"¬ÚÄB¨
= a,
#Æ ¦ ¬ (6.5.6)
§6.5
ô
∞ X
D
n=1
=
253
∞ ∞ ∞ X X X ηn − Eηn 1 1 1 2 2 = E(η − Eη ) ≤ Eη = E ξ12 I(|ξ1 | ≤ n) n n n 2 2 2 n n n n n=1 n=1 n=1
∞ n ∞ n X X 1 X 1 X 2 2 E ξ I (k − 1 < |ξ | ≤ k) ≤ k P (k − 1 < |ξ1 | ≤ k) 1 1 n2 n2 n=1 n=1 k=1
=
∞ X
k=1
k=1
∞ ∞ X X 1 2 k P (k − 1 < |ξ1 | ≤ k) ≤2 kP (k − 1 < |ξ1 | ≤ k) n2 n=k
k=1
≤ 2 (1 + E|ξ1 |) < ∞.
Ù ¶ Kronecker áØ (6.5.6) / a.s. ©ª" ×B¶ î » Å Ø P Å ¢¡ Ø û ¦ ¬ 9 û¾ Kolmogorov å û ¿ 0 < r < 2 Ë 6.5.3 (Marcinkiewicz øù¶ú ) ç {ξ , n ∈ N } × µ âãä ÀÁ" S = P ξ . ¤û Ü Å a Õ+ ∞
n=1
n
ηn −Eηn n
n
∞
n
n=1
Sn − na 1
nr
ê ã ì«Î4´ r
E|ξ1 | < ∞,
a=
(
→ 0 a.s.
(6.5.7)
Ñ
÷ àÅ
Eξ1 , ,
1 ≤ r < 2;
Ñ
0 < r < 1.
ÏÐÃð á ) 6Ä P E|ξ | < ∞ ⇐⇒ P |X | ≥ n < ∞. ) ì«®. ã ÄB¨ á "× fÄ%ê ã ®%"fÚ r 6= 1 % 1 < r < 2 ·%" É ®%"6fç Eξ = 0, æ´¬ÚÄB¨ S 1
∞
r
n
1 r
n=1
1
n 1
ó
nr
→ 0 a.s.
(6.5.8)
¿ÀÿÐ
1
ηn = ξn I(|ξn | < n r ), n ∈ N , ∞ ∞ P P 1 P (ηn 6= ξn ) = P (|ξn | ≥ n r ) < ∞,
æ´ × Ä
¬ÚÄB¨ n=1
(6.5.8),
n=1
n 1 X 1
¦ ¬ÄB¨
nr
k=1
ηk → 0 a.s.
(6.5.9)
©ª
(6.5.10)
∞ X Eηn 1
n=1
nr
.
254
Ñ
·"¸¶æ
0
∞ X E|ηn |
n
n=1
=
∞ X
j=1
(6.5.10)
n
∞ X
n=j
∞ X |E(ξn − ηn )|
n
1 r
1 r
r
õ´ ¦ Ð
n=1
2
n− r V ar ηn ≤
∞ X
1.
1
n− r
n=1
j X
∞ X
j=n
n
− r1
n=1
1
≤C
Eξ1 = 0,
n=1
1
j r P (j − 1 < |ξ1 |r ≤ j) ∞ X j=1
1
2
2
2
I"!CWX"#e%$>[?[@[A[BC
∞ X
2
n− r
n=1
∞ X
n=j
< {ξk }
n X
2
j r P (j − 1 < |ξ1 |r ≤ j)
j=1 ∞ X
2
n− r ≤ C
j=1
jP (j − 1 < |ξ1 |r ≤ j) < ∞.
6.5
T"&DE"'"({")"*[K
(2)P {ξk = ±2k } = 2−(2k+1) , P {ξk = 0} = 1 − 22k ; 1
1
(3)P {ξk = ±k} = 12 k− 2 , P {ξk = 0} = 1 − k − 2 .
cIWX>?@A[BC[_`L%+n[H[Z[^%,"-[q%.%/[_MR%'%([{")%*[v[X[w I"0s 6.4 q"1 5 s {ξ } vX%'"([{%)%*[w 4. = {ξ : n ≥ 1} TWX^>?@AB[C[_`R P P{ ξ } = 0 2 1. 3.
n
n
1
j r P (j − 1 < |ξ1 |r ≤ j)j 1− r
n− r V ar ηn < ∞.
j r P (j − 1 < |ξ1 |r ≤ j)
(1)P {ξk = ±2k } = 12 ;
2.
ÎÏ
k=1
n− r Eηn2 ≤
( ¿)í " Û ®/ j=1
1
j r P (j − 1 < |ξ1 |r ≤ j)j 1− r
áØ"
∞
=
j=1
1
j r P (j − 1 < |ξ1 |r ≤ j)
Kronecker n 1 P n− r Eηk → 0.
¶ î » Å Ø" ¦ ¬Ú PÙ Ä ∞ X
j=1
n=1
n X
jP (j − 1 < |ξ1 |r ≤ j) ≤ C (1 + E|ξ1 |r ) < ∞,
/ ô B¶
j=1
n=1
∞ X
1
n− r
·"¸¶æ¢è
∞ X
≤
j P (j − 1 < |ξ1 | ≤ j)
=C
∞ X
1
n− r ≤ C
1
n=1
j=1 ∞ X
(6.5.10)
/Ñ
=
1 r
∞ X
=
j=1
∞ X
1
j r P (j − 1 < |ξn |r ≤ j) =
jP (j − 1 < |ξ1 |r ≤ j) ≤ C (1 + E|ξ1 |r ) < ∞,
∞ X |Eηn |
Ð
n=1
n X
ÎÏ ¦ Ð
1
j=1 ∞ X
n=1
1
n− r
> 1,
j r P (j − 1 < |ξ1 |r ≤ j)
=C
×Æ·
∞ X
≤
1 r
1 r
Ò¢ÓÔ êBë$ìí
∞
n
n=1
§6.5
T"3"3WX"465%7[b%8%4M\[][H%9[^[>[?[@[A B[C[_MR {ξ } :";"'"({ 6. L {ξ : n ≥ 1} b[W[X%#[e%$[^[>[?[@ A B[C _ P (X = 0) = P (X = 2) = , I[J P a.s. w 7. < R b Rademacher >?@A_>="? P (R = ±1) = . IJ_>="? {R : n ≥ 1} bWX ^ Rademacher >?@ABC_MRH P a.s. w 8. = {R : n ≥ 1} bWX^ Rademacher >?@ABC_`Q%@ {ξ , n ≥ 1} WX_MIJK L P R ξ a.s. _MR P ξ a.s. w 9. = {ξ : n ≥ 1} b[W[X%#[e%$[^[>[?[@[A[B[C[_ {c : n ≥ 1} b[H%9%A[{[C[wMI[J[KML Eξ = 0, R P 5.
=
255
{ξn : n ≥ 1}
)"*w
n
n
∞
n=1
1
1 2
ξn 3n
∞
n=1
1 2
n
Rn n
n
n
2 n
n n
n
n
1
B"CK6D"E"F"G ). H[P"Q~%'%([{%)%*[I[J[_MN%I%J%K
1 n
(
10.
1
R H
[0, 1]
n
j=1
cj ξj → 0, a.s.
[S[i%L%M%N[{
0 ≤ f (x) ≤ cg(x), lim
n→∞
Z
1 0
···
Z
1 0
f (x), g(x),
O[f%+[n[[{
x ∈ [0, 1],
R1
f (x)dx f (x1 ) + · · · + f (xn ) dx1 · · · dxn = R01 . g(x1 ) + · · · + g(xn ) g(x)dx 0
c > 0,
SUTUVUW X"YJK _6Z"[%(%\[{%\"]%\%^%_[_6`%\%a%b"c[_ed%f_ 2001. [2] g"h"iK "@{[p"j%k[_`q"l%`%\%m%n"(%\%a%b%c_eo%p[_ 1996. [3] q"r"sK o[_6d%f%(%[\"a%b%c[_6d%f[_ 1994. [4] t"u"("\K _61[O%v[_ %w%x_ey[
"\%z[c[~%]%{_e|%}"]%~%a%b%c_ 1979. [5] """6""
"6"%% %%[p[o[%6y[
%]%~%a"b%c%6d%f% 1989. [6] [ ] W. "" y""[~%`"v%e%"%e%%e`"\%a%b%c%6d%f% 1980. [7] ""6"""6""%e%\"% %6y%¡%]%~%a"b%c%ed"f% 1985. [8] """6A"¢"N""£%6¤%l%`%\"m%n%(%\%a"b%c%eo"p% 2002. [1]
256