Comment on `Comment on `Some novel delta-function identities' by Charles P Frahm (Am. J. Phys 51 826--9 (1983))' by J. Franklin (Am. J. Phys 78 1225--26 (2010))

Yunyun Yang, Ricardo Estrada

We prove the formula for the second order "thick" distributional derivative of 1/r in 3 dimensional Euclidean space. This formula generalizes the well known Frahm formulas for the…