1. The problem statement, all variables and given/known data Write down a general function where E=f(r,D) for sphere (D=3), (where D is a dimensionality parameter, which describes how many orthogonal directions x,y,z the field drops off from its maximum). 2. Relevant equations 3. The attempt at a solution E=f(r,3) Am I correct in thinking I place the 3 where I have, and retain the r as an r. Then insert some function where the f is located?