1. The problem statement, all variables and given/known data I'm having difficulties with the integral sinh(ax)/sinh(pi*x) from -inf to inf. 2. Relevant equations 3. The attempt at a solution I've attached my attempt at a solution. First, I'm not sure that it's true that for the representation of the function f(z)=sinh(az)/sinh(pi*z) that it's true that the contributions from the vertical edges go to 0. Also, when I get to the end, I can't find a nice way to have an exponential factor times the original integral = the sum of residues... Any hints? Thanks.