- Thread starter
- #1

=Using change of variables technique seems to be easiest.

fX(x) = 1/2

fY(y) =1/2

f = 1/4 ( -1<X<1 , -1<Y<1)

Using u =x -y , v= x+y

Jacobian is del (x,y) / del (u,v) = 1/2

then J =1/2

and g (u,v) =1/8

Integrate g with respect to v then

gu = (u+2)/4 -2<u<0

and gu = ( -u+2) /4 , 0< u<2

is the PDF of u

Finally mean and variance, Can someone help me? Thanks