2-6 Use Stokes, Theorem to evaluate l curl F·dS. 2. F(x, y, z) = x 2 sin z i + y 2 j + xy k, S is the part of the paraboloid z 1-x-y, that lies above the xy-plane, oriented upward 3. F(x, y, z) = ze' i + x cos y J + xz sin yk, S is the hemisphere x2 + y2 + z2 = 16, y > 0, oriented in the direction of the positive y-axis