Let Fâ =(7z+3)iâ +4zjâ +(9z+9)kâ , and let the point P=(a, b,c), where a, b and c are constants. In this problem we will calculate div Fâ in two different ways, first by using the geometric definition and second by using partial derivatives. Consider a (three-dimensional) box with four of its corners at (a, b, c), (a + w, b, c), (a, b + w, c) and (a, b, c + w), where w is a constant edge length. Find the flux through the box. flux = Thus, we have div F Vector (x, y, z) = lim w Right arrow 0 Next, find the divergence using partial derivatives: div F Vector (x, y, z) = .