and Ex 2.4 is as follows.
thanks a lot for your help! 2.11 Let (X,Y) denote a random vector with the distribution described
in Exercise 2.4. Find the density function of the conditional distribution of X given Y=y and of
the conditional distribution of Y given X=x
2.4 Let X and Y denote real-valued random variables such that the distribution of (X,Y) is
absolutely continuous with density function p(x,y)=x3y21,x>1,y>1/x. Find the density functions
of the marginal distributions of X and Y.