3. For each of the following, compute I Is w.

(a) 8 is the portion of the surface z = x4 + y2 that lies over the unit square

[0,1] x [0,1], with upward pointing normal, and w = x dydz+y dz dx+z dx dy.

(b) 8 is the upper hemisphere z = J a2 - x2 - y2, with outward-pointing normal, and w = xdydz + ydz dx.

(c) 8 is the spherical cap z = v'a~2---x--'2~_-y"""'2 that lies inside the cylinder x2 +

y2 = b2, 0 < b <

a, with upward pointing normal, and w = xz dy dz + dz dx +

zdxdy.

(d) 8 is the truncated cone z = 2Jx2 + y2, 0 ~ Z ~ 2, with normal that points away from the z axis, and w = x dy dz + ydz dx + Z2 dx dy.