13. Explain how Coulomb's Law for the electric field (E = ) may be derived starting from Gauss' Law. Your explanation should be explicit in how you apply Gauss' Law (e.g. what surface) and in how you would evaluate the left-hand side and right-hand side of the equation. (Hint: Just apply Gauss' Law to a point charge. Make sure you properly explain (with words and equations) how to resolve the integral.)