# Thread: Joint probability problem

1. ## Joint probability problem

I am almost lost with this problem since I have a very basic idea about joint probabilities.

Qn
Random variables X and Y are uniformly distributed in the triangular region $0<=y<=x<=1$. Find fxy(x,y), the joint probability density function of X and Y.

my question is am I allowed to take conditional probabilities of X and Y are also uniformly distributed ?

descriptive answer will be highly appreciated.

2. Hello there,

Perhaps you could state what $f_{X,Y} (x, y)$ you were given? A $f_{X,Y} (x, y)$ does not have to be a conditional probability function.

In any case, the joint probability density function, $f_{X,Y} (x, y)$, has this relation with the cumulative density function: $f_{X,Y} (x, y) = \frac{\partial}{\partial x} \frac{\partial}{\partial y} F_{X, Y} (x, y)$.

I hope that this helps!