# How to find electric-charge density distribution

Given only an uniform electric field with unit vectors in the x, y, and z directions, how would you go about calculating the electric-charge density distribution p(r) for that electric field?

One nice formula you might try applying is one of Maxwell's equations: $$\nabla \cdot \mathbf{E} = \frac {\rho} {\varepsilon_0}$$ The symbol $\rho$ is the charge density that generates the electric field $\mathbf{E}$, and $\varepsilon_0$ is a proportionality constant called the permittivity of free space.