A point charge (q) is placed in a medium of

A point charge (q) is placed in a medium of constant permittivity 1 at a distance d from the infinite plane boundary with another medium of constant permittivity 2 Write the equation governing the potential function of the system. Hence, show that the potential function V1, in medium 1 is the same as that due to a point charge q and a point charge q(r-2)/( 1 +2) placed at an equal distance d on the other side , and the potential function V2 in medium 2 is the same as that produced by a charge 2q2/(1+ 2) at the position actually occupied by q in a complete space of permittivity 2