例2已知x的概率分布为(x)=2,X=12 求Y=sinX)的概率分布 x=4k-1 解 x SIn x=4-3k=1.2.3 0 x=2k P{=0P∑x=2=2PX=2 2 2k k=1 k: 13例2 已知X 的概率分布为 ( ) = , x = 1,2, 2 1 p x x 解 求 的概率分布      = X 2 Y sin  P Y{ 0} = 1 { 2 } k P X k  =   = =        = = k 1 2k 2 1 3 1 4 1 4 1 =       − = 1 1 { 2 } k P X k  = = =  1 4 -1 sin 1 4 - 3 1,2,3, 2 0 2 − =      = = =      = x k x x k k x k 