6. Evaluate the surface integral JJ F dS for the vector field F(x, y, z) = yi + xj, where S is the surface given by x2 + y2 + z2 = 4 in the first octant (x 2 0, y 2 0, z 2 0). Note: Flux Integrals: SS F . dS = SS F . ndS = JJ F . (rxre) dA (Outward orientation)