Two point charges are fixed on the y-axis, equal distance but opposite side. A charge of +q is located at y=+a and a charge +2q is located at y=-a.
The -q charge can also be placed at other points on the x-axis. At each labeled point (A is on the negative x-axis approximately all the way towards the end, B is at 0 both in the x and y, C is on the positive side of the x-axis approximately half way from the center and the end). Draw a vector to represent the direction of the net force on the -q charge due to the other two charges when it is at those points.