[1.3]设(X,Y)的分布律为-|||-Y 1 2 3-|||-X-|||--1 dfrac (1)(3) dfrac (a)(6) dfrac (1)(4)
1.设随机变量X与Y的联合分布律为-|||-Y-|||-X-|||--1 0 2-|||--1 dfrac (1)(6) dfrac (1)(12) 0-|||
25.设随机变量(X,Y)的分布律为X-|||-Y -1 0 1-|||--1 dfrac (1)(8) dfrac (1)(8) dfrac (1)(8)-|
1.设随机变量X与Y的联合分布律为-|||-Y-|||-X -1 0 2-|||--1 dfrac (1)(6) dfrac (1)(12) 0-|||-0 d
设二维随机变量(X,Y)的分布律为-|||-Y 0 1 2-|||-0 dfrac (1)(4) 0 dfrac (1)(4)-|||-1 0 dfrac (1
( x , y ) 的联合分布律为:Y x -7 2-|||--7 dfrac (5)(20) dfrac (2)(20) .dfrac (6)(20)-||
(5)设 (x,y)=ln (x+dfrac (y)(2x)) ,则 _(y)(1,0)= () .-|||-(A)1 (B) dfrac (1)(2) (C)
设随机变量X的分布律为X -1 0 1-|||-P dfrac (1)(5) dfrac (3)(5) dfrac (1)(5)设X -1 0 1-|||-P
3、设 (x,y)=arctan dfrac (x)(y), 则 (1,1)=-|||-(A)1; (B)0; (C) dfrac {1)(2),dfrac
设随机变量X,Y满足P(XY=0) =1,并且分布律分别为X -1 0 2 Y 0 1-|||-P dfrac (1)(6) dfrac (1)(3) dfra