设A是n阶复方阵, 则A满足( )时不一定半单.
A: [img=78x35]180372220769ed4.png[/img]
B: [img=78x35]180372221598626.png[/img]
C: [img=78x35]180372221dd379e.png[/img]
D: [img=135x36]180372222885b6e.png[/img]
A: [img=78x35]180372220769ed4.png[/img]
B: [img=78x35]180372221598626.png[/img]
C: [img=78x35]180372221dd379e.png[/img]
D: [img=135x36]180372222885b6e.png[/img]
举一反三
- 已知f(x)具有任意阶导数，且[img=18x32]17d622a39cdd9ca.png[/img](x)=[img=75x35]17d622a3a717d8a.png[/img]则当n为大于2的正整数时，f(x)的n阶导数[img=34x34]17d622a3b2d544c.png[/img](x)=[img=129x35]17d622a3c15d078.png[/img] ( )
- 设矩阵A，B，C，X为同阶方阵，A，B可逆，且有[img=79x19]18039d2116757cf.png[/img]，则矩阵X= ( ) A: [img=75x22]18039d211feab03.png[/img] B: [img=75x22]18039d2128d4a42.png[/img] C: [img=75x22]18039d2130fba14.png[/img] D: [img=75x22]18039d213a8ae69.png[/img]
- 设[img=77x19]1802e2aa5a4095f.jpg[/img]，则E(X)=4，D(X)=4/3.
- 设随机变量X～N(2，9)，Φ(x)为标准正态分布函数，则P{2<X≤4}=( ). A: [img=36x43]1803b451cf414b0.png[/img] B: [img=67x43]1803b451d70a0e2.png[/img] C: [img=76x43]1803b451df63707.png[/img] D: [img=67x43]1803b451e721484.png[/img]
- 设随机变量 X ~ e([img=11x19]1803bbe33f2dc36.png[/img])，则 D(X )= [img=18x43]1803bbe34777894.png[/img].