(4) Use double integrals to find the volume of the given solids. (a) The solid bounded by z = 2 y, z = 0, y = 0, y = x, and x = 1. I 2 ] Y (b) The solid below z = e and above z = -e-that intersects the xy-plane in the region R = {(x, y)|0 y 1, 0xy}. I R Y