1. The problem statement, all variables and given/known data There are 3 charges, each denoted q, the first at (0,a), the second at (0,0) and finally one at (b,0). What is the resultant electric field at point P, (b,a)? 2. Relevant equations E=q/(4πεo r2) for a point charge 3. The attempt at a solution So I know I need to use the superposition principle and sum the fields caused by the individual charges but I'm not sure whether I need to consider the fact that their fields wont necessarily be in the same direction. My attempt gave me E= q/(4πεo (1/a2 + 1/b2 + 1/(a2 + b2)) in the direction the same as sqrt(a2 + b2). Thanks for any help, I've been debating this with friends.