verify that this is a valid jdf.
f(y1, y2)= 6y1^2 y2 0<=y1<=y2, y1+y2<=2
I was trying to integrate y1 from 0 to y2
and y2 from 0 to 2
also i tried y1 from 0 to y2
and y2 from 0 to 1
all times 2
but still not confident with my answers. any help would be great