Charge density causing an Electric Field

[RP8]

So the problem is: The electrostatic field is E =g|r|r where g is a constant. Find the charge density p(r) which can generate the field?

My attempt was gauss law: divE=p/ε₀

But I'm struggling to take divE. I guess r=x+y+z?

Any advice much appreciated!

 

[Matterwave]

Take the divergence in spherical coordinates, it's much easier.

http://en.wikipedia.org/wiki/Divergence

See the "spherical coordinates" section.