Evaluate the surface integral F dS for the given vector field F and the oriented surface S. In other words, find the flux of F across S. For closed surfaces, use the positive 5 (outward) orientation. F(x, y, z)-xy i + yzj+ zx k s is the part of the paraboloid z = 6-x2-y2 that lies above the square 0 x 1,0 y 1, and has upward orientation