As we know from coulomb's law that: $$\vec{E} = \frac{q}{4\pi\epsilon R^2} \hat{R}$$
using the above equation, how can I verify that: $$\vec{\nabla}\cdot \vec{E}=\frac{q}{\epsilon}$$
I have tried to do it a home, but couldn't figure it out. Explicitly showing all steps would be very much appreciated.
