2. Compute the following multiple integrals using suitable method. (a) a³ dady, where R is the region bounded by x-axis, y-axis, x = 2, y = 1 + x, and y = 3-x. S S S 1 x²- y² dxdydz, where V is the region which is bounded above by a sphere x² + y²+z² = 4 and is bounded below by a plane z = 1.