........................(2.106)

                                       and ...............(2.107)

                                      ............................(2.108)

Thus we find that V_d satisfies Laplace’s equation in V_r and on the conductor boundaries V_d is zero as V₁ and V₂ have same values on those boundaries. Using vector identity we can write:

...............(2.109)

Using the fact that , we can write

..........................(2.110)