Assuming that S satisfies the conditions of the Divergence Theorem and the scalar functions and components of the vector fields have continuous second order partial derivatives, find , where a is the constant vector.
Evaluate the surface integral for the given vector field F and the oriented surface S. In other words, find the flux of F across S. in the first octant, with orientation toward the origin.
Use the Divergence Theorem to calculate the surface integral ; that is, calculate the flux of across . S is the surface of the box bounded by the coordinate planes and the planes .