2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/101391The second-order partial derivatives of the Coulomb potential of a point charge can be regularized using the Coulomb potential of a charge of the oblate spheroidal shape that a moving rest-frame-spherical charge acquires by the Lorentz contraction. This `physical' regularization is shown to be fully equivalent to the standard delta-function identity involving these derivatives.8 pages, no figures; an appendix is added in which the `physical'-regularization result is generalized and proved using the theory of generalized functions and derivativesClassical PhysicsGeneral Physicstext