I need to calculate the electric field caused by a square of wire. I can get the field caused by the sides of the square that are perpendicular to the x axis but I can't figure out how to get the field caused by the side parrallel to the x axis. here is an image of the problem. http://img152.imageshack.us/my.php?image=46151722si8.png At the origin there is no force in the x direction but in other places there is. I know the the electric field = (k)q/r^2 but when I try to integrate I think I will need 3 variables. I'd appreciate any help.