过[img=93x25]1803554a7cde8cb.png[/img]，[img=107x25]1803554a84c3df9.png[/img]和[img=79x25]1803554a8d04e36.png[/img]三点的平面的方程为（ ）
A: [img=267x25]1803554a9734db9.png[/img]
B: [img=267x25]1803554aa1c20f2.png[/img]
C: [img=267x25]1803554aac4c884.png[/img]
D: [img=267x25]1803554ab7828a8.png[/img]
A: [img=267x25]1803554a9734db9.png[/img]
B: [img=267x25]1803554aa1c20f2.png[/img]
C: [img=267x25]1803554aac4c884.png[/img]
D: [img=267x25]1803554ab7828a8.png[/img]
举一反三
- 求不定积分[img=121x54]17da653839aa6ae.png[/img]； （ ） A: log(x^2 + 3*x + 25/4)/4 + (5*atan(x/2 + 3/4))/4 B: log(x^2 + 3*x + 25/4)/4 C: (5*atan(x/2 + 3/4))/4 D: log(x^2 + 3*x + 25/4)/4 - (5*atan(x/2 + 3/4))/4
- 设随机变量X和Y的概率密度分别为：[img=474x78]1802e8d4b06a97d.png[/img]且X和Y相互独立，则2X-3Y的方差为( )． A: 25/16 B: 5/4 C: 25/9 D: 5/3
- D(X)=25,D(Y)=36,[img=58x17]17e0c5b1a8ccbe4.jpg[/img],则D(X+Y)=(),D(X-Y)=()
- 随机变量 X 服从均匀分布[img=296x96]17de89393460b92.png[/img]则D(X)=( ). A: 4.5 B: 25/12 C: 1/5 D: 1
- For a stationary AR(1) model, [img=114x22]180300ca641c929.png[/img], where [img=112x25]180300ca6bdc586.png[/img]. Then [img=73x25]180300ca73e9f53.png[/img] A: 5 B: 1.25 C: 25/16 D: 25/9