I am trying to calculate the vector magnetic potential for a rod of length L extending along the Z-axis. I was asked to find the magnetic potential at a point P which is a distance r from the center of the rod in the XY plane. I know the formula I have to use is the vector Poisson's equation A = u / 4pi * integral ( J / R') dv', where the bounds are in respect to v'. The dv' refers to the volume of the object (the rod). I am not sure how I might start this problem. I have thought about using J = I * (pi * a^2), where I is the current of the rod and a is the radius. As well, R' can be calculated using r = (z^2 + r^2)^1/2. Besides that, I am confused on how I might take into account of the volume and current of the rod. I would greatly appreciate any help that can be offered.