(949, #15) Evaluate

where F(x,y,z) = < ey, y ex , x2 y> and S is the part of the paraboloid z = x2 + y2 that lies abve the square x = 0..1, y = 0..1 and has upward orientation.

Solution. The parametrization of the surface is

x = x, y = y, z = x2 + y2, x = 0..1, y = 0..1.

In addition rx x rz = < -2 x , -2 y, 1>, so the orientation is upward. Consequently