Joint cumulative function?

Question

assume the joint pdf of X and Y is

f x,y (x,y) ={ x*y*e^ -[(x^2 + y^2)/2] 0<x, y

{ 0 otherwise

Find Fx,y(x,y)

i'm having trouble with the infinity signs most of the time i'm getting 0 or infinity

please give me a detailed explanation. thanks a million

Answer 1

Isn&#039;t the cumulative function F (X,Y) this:- ?

integral 0-X integral 0-Y x*y* pdf(x,y) dx dy