# Consider a line charge density A(z) that is localized on the z axis from z=-a to z=+a. By considering the monopole, dipole, and quadrapole moments of the charge distribution, find an approximation for the potential p(r) to leading order only (i.e. the first non- vanishing term) in the multipole expansion, for each of the following three cases: a) A(z) Acos(TZ/2a) b) A(z) Aosin(TZ/a) c) MZ) Aocos(Tz/a)

Question

It's an electromagnetics problem.