Anti-Meson

I have used the cylindrical version, though this problem only depends on r so maybe use spherical? I integrated the partial differential with respect to r.

if I assume that Er is not a function of r but a constant then,

[tex] \frac{\partial (r E_{r})}{\partial r} = E_{r} [/tex]

or if i use a radial divergence from the beginning:

[tex] \nabla . E = \frac{\partial (E)}{\partial r} [/tex]

but by using that I get:

[tex] E = \frac{\rho r}{\epsilon_0} [/tex]

i.e missing a factor of 3