2. (a) Compute the line integral (F-dr, where F = -2yi + 4z j and C is the positively oriented are of the circle + y-9 from the point (3, 0) to (0, -3). (b) Compute the surface integral (f, f(x, y, z) ds, where f(x, y, z) = 6xyz and S is the portion of the plane z -y + ==2a that lies above the square (0, a] x [0, a] in the ry-plane.