"Where's The Electric Field 0" Problem 1. The problem statement, all variables and given/known data I'm given an electron at the origin with charge "e", and an ion (with "+4 e" charge), both on the x axis. The distance between the electron and proton is given as 11 nanometers. I need to find where the electric field will be equal to 0. 2. Relevant equations E=kq/(d^2) 3. The attempt at a solution So I know that the electric field is 0 where the individual electric fields from the electron and ion cancel each other out (right between them on the x axis). I set negative kq/(d^2) for the electron equal to positive kq/(d^2) for the ion, so k(4e)/(d^2) = -k(e)/[(11-d)^2] (please note the negative sign on the right hand side, because my thinking was that this is an opposite electric field, so it should have an opposite sign) The k's and e's cancel out, but every time after doing the algebra, I simply get a quadratic equation with imaginary solutions. Any help would really be appreciated.