# Solving Laplace's Eqn: Setting Zero of Potential

by bcjochim07
Tags: laplace, potential, setting, solving
 Sci Advisor HW Helper PF Gold P: 2,602 Since the electric field is the gradient of the potential, $$\vec{E} = - \nabla V$$ (for electrostatics), a constant shift in the potential $$V' = V + c$$ doesn't change the electric field. Therefore we are usually free to define the location of $$V=0$$ by adding a constant term to the potential. In your examples, choosing $$V(z=0) = 0$$ is just the most convenient choice, but it was not the only one.