A: [img=187x61]1803a57c10996ae.png[/img]
B: [img=186x55]1803a57c1b973b7.png[/img]
C: [img=186x55]1803a57c2651cfd.png[/img]
D: [img=193x55]1803a57c30d12df.png[/img]
举一反三
- 设D(X)=25,D(Y)=36,[img=58x17]17e0bcfc3a8fb71.jpg[/img],则D(X+Y)=( ) A: 61 B: 85 C: 37 D: 57
- 设[img=28x19]17da41b38e91a03.jpg[/img]为可导函数,则[img=63x37]17da426f632f014.jpg[/img]的导数是( ) A: f(x) B: f(x)+C C: f '(x) D: f '(x)+C
- 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]
- X~N(1,1), 密度函数为[img=37x25]18038fe689205b5.png[/img], 分布函数为F(x), 则（ ） A: [img=198x25]18038fe690a03ee.png[/img] B: [img=101x25]18038fe69af96aa.png[/img] C: [img=67x25]18038fe6a3b8e5b.png[/img][img=118x25]18038fe6ab93d6f.png[/img] D: F(x)=F(-x)
- Which of the following propositions is false,set A = {x,x is an integer and[img=60x23]1803a1c6eebb7a3.png[/img]} ? ( ) A: [img=113x25]1803a1c6f77ce06.png[/img] B: [img=139x25]1803a1c7001fe79.png[/img] C: [img=51x22]1803a1c70863f61.png[/img] D: {x|x is an integer and |x| 4}[img=33x22]1803a1c711a7c63.png[/img]
内容
- 0
Which of the following propositions is false,set A = {x,x is an integer and [img=60x23]1803a1c503ffa04.png[/img]} ? ( ) A: [img=113x25]1803a1c50cc3162.png[/img] B: [img=139x25]1803a1c514e60ea.png[/img] C: [img=51x22]1803a1c51dd52ef.png[/img] D: {x|x is an integer and |x| <4} [img=33x22]1803a1c525cf1bd.png[/img]
- 1
设 f(x, y) 可微, g(x, y) 也可微, 复合函数 f(x, g(x, y)) 关于 x 的偏导数为 A: [img=99x18]1803497b5fbf17f.gif[/img] B: [img=220x20]1803497b67f53f8.gif[/img] C: [img=278x20]1803497b70d3874.gif[/img] D: [img=156x20]1803497b78c5940.gif[/img]
- 2
1.设随机变量X的密度为[img=186x61]18034ea953ec9dd.png[/img]则常数A=________，概率[img=146x25]18034ea95d30d08.png[/img]__________. A: A=2，P(X>1|X<2)=[img=39x24]18034ea9659b618.png[/img] B: A=-2，P(X>1|X<2)=[img=39x24]18034ea9659b618.png[/img] C: A=2，P(X>1|X<2)=[img=47x44]18034ea9768a8c2.png[/img] D: A=-2，P(X>1|X<2)=[img=47x44]18034ea9768a8c2.png[/img]
- 3
设(X，Y)的分布函数为[img=549x53]18031e937a7b053.png[/img]则(X，Y)关于X的边缘分布函数FX(x) = （ ）． A: [img=287x55]18031e93855481e.png[/img] B: [img=285x52]18031e93918b0ca.png[/img] C: [img=296x55]18031e939bc0749.png[/img] D: [img=294x56]18031e93a5c4883.png[/img]
- 4
设(X，Y)的分布函数为[img=549x53]1803a74a8f6ca05.png[/img]则(X，Y)关于X的边缘分布函数FX(x) = （ ）． A: [img=287x55]1803a74a9a08d05.png[/img] B: [img=285x52]1803a74aa4ac3b9.png[/img] C: [img=296x55]1803a74aae81937.png[/img] D: [img=294x56]1803a74ab8d5dc7.png[/img]