3. For each of the following, find fffE f dV.

(a) f(x, y, z) = z2 and E is the set of points satisfying x2 + y2 + Z2 :::; 6 and z 2: x2 + y2.

(b) f(x, y, z) = eZ and E is the set of points satisfying x2 +y2 + z2 :::; 9, x2 +y2 :::;

1, and z 2: O.

(c) f(x, y, z) = (x - y)z and E is the set of points satisfying x2 + y2 + Z2 :s 4, z 2: J x2 + y2, and x 2: O.