(5) Find two other positions at which the test charge has this potential.
The question asks for two points of equal potential. For the sake of ease of calculation, it is best to choose points along the line that joins the two charges, one point on either side of the charges. Label these points x. At either point x, one charge will be a distance x from the point, while the other will be a distance x+.14 m from the point. First consider the point x lying to the left of the 2e charge. The potential at that point is the sum of the potentials caused by the two point charges. The desired
value for the potential is given in equation (7). This value can be set equal to the sum of the individual potentials:
