The joint distribution function for two random variables X and Y is Assume a Fxy(x,y) = u(x)u(y)[1 - e-ax – e-ay + ea(x+2)] 0.5, find the probabilities: a) P{X ≤ 1, Y≤2} b) P{0.5 <X ≤ 1.5} c) P{-1.5 <X ≤ 2,1 < Y≤3}