Problem 2.34b | Introduction to Electrodynamics (Griffiths)

An alternative method to find the energy required to construct a uniformly charged sphere. Instead of integrating across the sphere, we integrate across all space, therefore r stretches all the way to infinity in the integral. The derivation of the formula used in this video is pretty neat, in my opinion, since it removes an annoying surface integral term by extending the space we integrate into all space, leaving us with a rather neat and general formula.