设a=[1 2; 3 4]，则[a; [5 6]]的运行结果为ans=（ ）.
A: [img=77x51]1803dae6697dd37.png[/img]
B: [img=77x51]1803dae67329ffb.png[/img]
C: [img=55x63]1803dae67ce0735.png[/img]
D: [img=55x63]1803dae686bc963.png[/img]
A: [img=77x51]1803dae6697dd37.png[/img]
B: [img=77x51]1803dae67329ffb.png[/img]
C: [img=55x63]1803dae67ce0735.png[/img]
D: [img=55x63]1803dae686bc963.png[/img]
举一反三
- 设a=[1:4; 5:8]，则a(:,2:2:end)的运行结果为ans=（ ）． A: [img=77x51]1803dae685eb076.png[/img] B: [img=77x51]1803dae68e17e33.png[/img] C: [img=53x51]1803dae696faf8f.png[/img] D: [img=53x51]1803dae69ff1885.png[/img]
- 设a=[1:4; 5:8]，则a(:,2:2:end)的运行结果为ans=（ ）． A: [img=77x51]1803de1768b78fb.png[/img] B: [img=77x51]1803de1771d6a92.png[/img] C: [img=53x51]1803de177961115.png[/img] D: [img=53x51]1803de178223ec5.png[/img]
- 函数[img=103x33]17e0b09051e076c.jpg[/img]的反函数是 未知类型：{'options': ['y=1-3cosx,x[img=6x11]17e0b0905fe87f4.jpg[/img][0,[img=8x11]17e0a7285a871a0.jpg[/img]]', ' y=1+3cosx,x[img=6x11]17e0b0905fe87f4.jpg[/img][0,[img=8x11]17e0a7285a871a0.jpg[/img]]', ' y=1-3sinx,x[img=6x11]17e0b0905fe87f4.jpg[/img][0,[img=8x11]17e0a7285a871a0.jpg[/img]]', ' y=1+3sinx,x[img=6x11]17e0b0905fe87f4.jpg[/img][0,[img=8x11]17e0a7285a871a0.jpg[/img]]'], 'type': 102}
- 设随机变量[img=75x25]1802d5ab02ff46a.png[/img]，且已知 E[(X - 1)(X + 2)] = 6，则[img=30x19]1802d5ab0aa816f.png[/img] A: 1 B: 2 C: 3 D: 4
- 设随机变量X~P([img=11x19]17de5dcc6b8a740.png[/img]),且已知E [(X-1)(X-2)]=1,则[img=11x19]17de5dcc6b8a740.png[/img]= .