Let X1 and X2 have the joint pdf fx1,X, (X1, X2) = 2e-1-12 for 0

Let Xl and X2 have the joint pdf f Xl,X2 (Cl , for O < < a'2 < 00, and zero elsewhere. What is the joint pdf of Yl 2X1 and Y2 O (Ill) (l) fYl,Y2 (Yl,Y2) for O < 'Yl < < 00. = e Yl+Y2 for O < Yl < 00 and O < 00. (II) fYI,Y2 (Yl,Y2) = e Yl+Y2 for O < < < 00. (Ill) fYI,Y2 (Yl,Y2) (IV) fY1,Y2 (Yl,Y2) e YlY2 for O < Yl < 00 and O < 00.