Let [img=47x25]1803a319caed5c0.png[/img] be the uniformly distributed within the unit circle, and the the joint probability density function be [img=501x61]1803a319d67d32e.png[/img]Then the marginal distribution of X in [img=47x25]1803a319caed5c0.png[/img] is also the uniform distribution.
举一反三
- If X and Y are any two independent continuous random variables whose probability density is [img=41x25]1803dc1d154ea64.png[/img] and [img=38x26]1803dc1d1dd7772.png[/img],and whose distribution function is [img=47x25]1803dc1d26f6f50.png[/img] and [img=42x25]1803dc1d300d282.png[/img],then [img=47x25]1803dc1d26f6f50.png[/img] + [img=42x25]1803dc1d300d282.png[/img] must be the distribution function of a random variable.
- 下列4个集合中是空集的是（） A: ｛x|[img=18x22]1802f060e2f728f.png[/img]+1=0｝ B: ｛x|[img=18x22]1802f060e2f728f.png[/img]<-x｝ C: ｛x|[img=18x22]1802f060e2f728f.png[/img]=0｝ D: ｛x|[img=18x22]1802f060e2f728f.png[/img]-1=0｝
- 下列4个集合中是空集的是（） A: ｛x|[img=18x22]1803d021d498831.png[/img]+1=0｝ B: ｛x|[img=18x22]1803d021d498831.png[/img]<-x｝ C: ｛x|[img=18x22]1803d021d498831.png[/img]=0｝ D: ｛x|[img=18x22]1803d021d498831.png[/img]-1=0｝
- 下列4个集合中是空集的是（） A: ｛x|[img=18x22]1803d0240bcad39.png[/img]+1=0｝ B: ｛x|[img=18x22]1803d0240bcad39.png[/img]-x｝ C: ｛x|[img=18x22]1803d0240bcad39.png[/img]=0｝ D: ｛x|[img=18x22]1803d0240bcad39.png[/img]-1=0｝
- 用性质描述法表示集合{-5 ，5}，正确的是（） 未知类型：{'options': ['{x〡x+5=0}', ' {x〡x-5=0}', ' {x〡[img=50x19]17da5f73610949a.jpg[/img]}', ' [img=112x31]17da5f736ab6c3e.jpg[/img]'], 'type': 102}