Here it goes.
2 pontual charges (Q>0), placed in (0,a,0) and (0,-a,0): calculate de vector E(x,0,0) along xx
The Attempt at a Solution
I tried to use E=1/(4*pi*epsilon naught) * Q/r2
but when i make Q/(x ex + a ey)2 and (x ex + (-a) ey)2
i don't know what to do...
(I think i have doing something wrong)