Find the interaction energy in Eq. 2.47) for two point charges, q1 and q2, a distance a...

Find the interaction energy in Eq. 2.47) for two point charges, q₁ and q₂, a distance a apart. [Hint: Put q₁ at the origin and q₂ on the z axis; use spherical coordinates, and do the r integral first.]

Reference equation 2.47