Hi I think I am missing something in the solution of this problem.
I have the final solution of the problem but I get something a little bit different:
A circular disk of uniform surface integral "RHOs" and radius a lies in the x-y plane with center at (0,0,0). Find the potential PHI(z) along the z axis when the potential is Vo is at the center of the disk, using the potential formula.
the final answer is:
I dont know how they get the variable a in bold.
Please can someone tell me what I get it wrong.