设随机变量(X,Y)的联合概率密度[img=241x53]18038d32b0b82eb.png[/img],则E(XY)= .
举一反三
- 设随机变量(X,Y)的联合概率密度[img=241x53]18038d32a603f96.png[/img],则E(X)= .
- 设随机变量(X,Y)的联合概率密度[img=241x53]17de892d0677790.png[/img],则E(X)= .
- 设随机变量(X,Y)的联合概率密度[img=241x53]17e441547e2f9a5.png[/img],则[img=260x51]17e44154880cd62.png[/img] A: √ B: ×
- 设随机变量(X,Y)的联合概率密度[img=241x53]1802daf43c2cce7.png[/img],则[img=260x51]1802daf446f6e0b.png[/img]
- 设随机变量(X,Y)的联合概率密度[img=241x53]1803c286587e44b.png[/img],则[img=260x51]1803c2866370f6f.png[/img]