Hi, I posted this on the homework forum, but I haven't gotten any responses there. I thought there might be a better chance here. 1. The problem statement, all variables and given/known data I have the ODE h'' + h'/r + λ2h = 1, where h = h(r), and I want to find h(r). 2. Relevant equations The corresponding homogeneous equation is a Bessel equation that has the solution hh = c1J0(λr) + c2Y0(λr), where J0 and Y0 are Bessel functions. Now I was planning on using h(r) = hh + hp, where hp is a particular solution of the ODE. 3. The attempt at a solution To find hp, I tried using variation of parameters, but I get to a point where I need to both differentiate and integrate a Bessel function, which turns out to be pretty hard. I'm wondering if I'm going in the wrong direction, or if my logic here is even valid. Thanks!