1. The problem statement, all variables and given/known data Two infinitely grounded metal plates at y=0 and y=a are connected at x=b and x=-b by metal strips maintained at a constant potential V. Find the potential inside the rectangular pipe. 2. Relevant equations Laplaces Equation 3. The attempt at a solution I posted a photo of what i've done so far. The line indicates where I stray off I'm confused because how can I use fouriers trick with cosh?