Final answer:
To find the two points on the x-axis where the electric potential is zero due to a charge +Q at the origin and -3Q at x = a, you need to solve the equation kQ/r1 - 3kQ/r2 = 0, which will yield two points: one between the charges and one to the right of -3Q.
Step-by-step explanation:
The question requires finding two points on the x-axis where the electric potential V = 0 due to a charge +Q at the origin and a charge -3Q at position x = a. The potential V at any point x on the x-axis due to a point charge can be calculated using the formula V = kQ/r, where k is the Coulomb's constant and r is the distance from the charge to the point on the x-axis.
To find the points where V = 0, we set up the equation kQ/r1 - 3kQ/r2 = 0, where r1 is the distance from the origin to the point and r2 is the distance from the point to the charge at x = a. There are two solutions to this equation: one between the charges and one to the right of the charge at x = a. By solving the equation, you can find the exact locations on the x-axis.