题目内容

设二维随机变量(X,Y)服从二维正态分布,则随机变量ξ=X+Y与η=X-Y不相关的充要条件为

A. EX=EY
B. E(X2)- (EX)2= E(Y2)- (EY)2
C. E(X2)= E(Y2)
D. E(X2)+(EX)2=E(Y2)+(EY)2

查看答案

搜索结果不匹配？点我反馈

更多问题

Their appearance usually marks a cultural and economic renaissance, heralding a new golden age.

A. which indicates
B. which indicating
C. what indicates
D. what indicating

查看答案

The focus on the city is significant, as are the ideas behind the recreation.

A. because the ideas behind the recreation are significant.
B. and the ideas behind the recreation are also significant.
C. while the ideas behind the recreation are significant.
D. though the ideas behind the recreation are significant.

查看答案

Its entrepreneurs and scholars invented technologies still in use today...

A. when are still in use
B. where are still in use
C. what are still in use
D. which are still in use

查看答案

But while the epic of Augustan Rome traces the journey of a single man, Qingming Shanghe Tu is a comprehensive picture of society in Bian Jing.

A. Whereby
B. Wherein
C. Whereas
D. Wherever

查看答案

设二维随机变量(X,Y)服从二维正态分布,则随机变量ξ=X+Y与η=X-Y不相关的充要条件为

A. EX=EY B. E(X2)- (EX)2= E(Y2)- (EY)2 C. E(X2)= E(Y2) D. E(X2)+(EX)2=E(Y2)+(EY)2

Their appearance usually marks a cultural and economic renaissance, heralding a new golden age.

The focus on the city is significant, as are the ideas behind the recreation.

Its entrepreneurs and scholars invented technologies still in use today...

But while the epic of Augustan Rome traces the journey of a single man, Qingming Shanghe Tu is a comprehensive picture of society in Bian Jing.

A. EX=EY
B. E(X2)- (EX)2= E(Y2)- (EY)2
C. E(X2)= E(Y2)
D. E(X2)+(EX)2=E(Y2)+(EY)2