Alternate derivation of the Liénard–Wiechert fields of a point charge

The Liénard–Wiechert fields for a point charge are derived from a suitable integral representation for the electric and magnetic fields. In this derivation one does not calculate derivatives of retarded functions. Retardation is introduced into the fields at the end of the calculations. The free‐space retarded Green function turns out to be an essential ingredient in this derivation. A heuristic argument is given for introducing this Green function. The derivation presented here might be used in undergraduate courses on electromagnetic theory.