If A is a [img=40x20]1803c4e438d5e6e.png[/img] matrix and [img=141x21]1803c4e44127ce1.png[/img], then A must be singular.
举一反三
- If A is a [img=40x20]180348ee73f28ea.png[/img] matrix , [img=124x21]180348ee7d54af8.png[/img], then A must be singular
- If A is a [img=32x20]1803c4e3bc9049f.png[/img] matrix and [img=133x21]1803c4e3c4a459d.png[/img], then A must be singular.
- 随机变量X服从均匀分布[img=246x104]1803bbdf7304c7f.png[/img]则E(X)=( ) A: 4 B: 5 C: 0.5 D: 1
- 设[img=77x19]1802e2aa5a4095f.jpg[/img]，则E(X)=4，D(X)=4/3.
- 已知随机变量X的分布函数为[img=136x49]1803b69024c8270.png[/img] ，则X的均值和方差分别为 A: E(X)=2, D(X)=4 B: E(X)=4, D(x)=2 C: [img=162x43]1803b6902cd8bfb.png[/img] D: [img=162x43]1803b69034d9ffd.png[/img]