条件概率密度（在线等）已知f(x,y)=e^-y(0

条件概率密度（在线等）已知f(x,y)=e^-y(0
条件概率密度（在线等）
已知f(x,y)=e^-y(0

条件概率密度（在线等）已知f(x,y)=e^-y(0
P(A|B)=P(AB)/P(B)
所以P(X>2|Y2,Y4)e^(-y)dy / ∫(0->4)dx∫(x->4)e^(-y)dy
=(e^2-3)/(e^4-5)

答案为(e^2-3)/(e^4-5)