X~U[0,5]为均匀分布，关于x的概率密度为f(x)=1/5 (0=5/3-1/3y}=1-P{x<=5/3-1/3y}fY(y)=F'Y(y)=[1-P{x<=5/3-1/3y}]'=f(5/3-1/3y)*(1-5/3+1/3y)'=1/15,-10<=y<5fY(y)=0,其他
