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
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-|||
5.设二维离散型随机变量(X,Y)的联合分布律如下.-|||-2 3-|||-X-|||-1 dfrac (1)(6) dfrac (1)(9) dfrac (
设l为椭圆dfrac ({x)^2}(4)+dfrac ({y)^2}(3)=1,其周长记为a,则dfrac ({x)^2}(4)+dfrac ({y)^2}(
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)-|
6、设(X,Y)的分布律为 X-|||-Y 0 2-|||-0 k dfrac (5)(33)-|||-1 dfrac (5)(33) dfrac (1)(66
3、设 (x,y)=arctan dfrac (x)(y), 则 (1,1)=-|||-(A)1; (B)0; (C) dfrac {1)(2),dfrac
(13)设随机变量(X,Y)的联合概率分布如下.-|||-X-|||-①-|||-0 dfrac (1)(8) a dfrac (1)(4)-|||-1 dfr
设随机变量X与Y的联合分布律为X/Y 1 2 3-|||-1 1/9 2/9 2/9-|||-2 0 dfrac (1)(9) dfrac (2)(9)-|||
16.设X与Y相互独立,其分布列分别为-|||-X -2 -1 0 dfrac (1)(2)-|||-p dfrac (1)(4) dfrac (1)(3) d