Exercise 25

Use the Chain Rule to find the indicated partial derivatives. \(N = \frac{p+q}{p+r}\), \(p = u + vw\), \(q = v + uw\), \(r = w + uv\); find \(\frac{\partial N}{\partial u}\), \(\frac{\partial N}{\partial v}\), \(\frac{\partial N}{\partial w}\) when \(u = 2, v = 3, w = 4\).