Which of the following are the non-extraordinary subgroups of the 8th-order cycle group G=[V,E] ( )[img=264x123]1803a1c68512ce9.png[/img]
A: [img=179x25]1803a1c68dcfe63.png[/img]
B: [img=179x25]1803a1c696ca64e.png[/img]
C: [img=179x25]1803a1c69ed3cb9.png[/img]
D: [img=179x25]1803a1c6a773cf9.png[/img]
A: [img=179x25]1803a1c68dcfe63.png[/img]
B: [img=179x25]1803a1c696ca64e.png[/img]
C: [img=179x25]1803a1c69ed3cb9.png[/img]
D: [img=179x25]1803a1c6a773cf9.png[/img]
A,B,C
举一反三
- 设X，Y为两个随机变量，且[img=179x25]1803395d555effc.png[/img] , [img=226x25]1803395d61f1a43.png[/img] ,则[img=143x25]1803395d6f00057.png[/img]= ( )． A: 1/7 B: 3/7 C: 4/7 D: 5/7
- （5切比雪夫不等式）设随机变量X的期望E(X)=μ，方差D(X)=[img=14x17]17e43703436673a.jpg[/img]，利用切比雪夫不等式估计P{|X-E(X)|[img=30x16]17e437fbfd2e01c.jpg[/img]}>; () A: 1/9 B: 1/3 C: 8/9 D: 1
- 设随机变量X~E(1)，则[img=49x23]17de8922460f18c.png[/img]=（ ） A: 1 B: 1/3 C: 1/9 D: 1/2
- 设随机变量X[img=138x21]17e438ba4537f6f.jpg[/img],则由切比雪夫不等式[img=134x19]17e43eeb4a5ffad.jpg[/img] A: 1/9 B: 4/9 C: 8/9 D: 1
- 设随机变量X[img=138x21]17e0bcf1c82597b.jpg[/img],则由切比雪夫不等式[img=134x19]17e0bd06202ebd9.jpg[/img] A: 1/9 B: 4/9 C: 8/9 D: 1
内容
- 0
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
- 1
设随机变量X的概率密度为[img=157x51]1803b4519b2ecc0.png[/img]则方差D(X)=( ). A: 1/3 B: 1/6 C: 1/9 D: 1/18
- 2
X为随机变量，E(X)=-1,D(X)=3,则[img=105x27]17de66c4ef75d99.png[/img] A: 18 B: 9 C: 30 D: 32
- 3
设[img=132x25]1802fbbcbe9d3a1.png[/img]。DSB-SC信号[img=179x25]1802fbbcc918fe6.png[/img]的功率是_____ A: 6 B: 9 C: 18 D: 12
- 4
设[img=132x25]18036114169db2f.png[/img]。DSB-SC信号[img=179x25]18036114210883c.png[/img]的功率是_____ A: 6 B: 9 C: 18 D: 12