Given the joint PDF f(x,y)=8xyf(x, y) = 8xyf(x,y)=8xy for 0≤y≤x≤10 \le y \le x \le 10≤y≤x≤1, what is the marginal density fY(y)f_Y(y)fY(y)?
4y(1−y2)4y(1-y^2)4y(1−y2)
4y4y4y
8xy8xy8xy
8x8x8x