Actually I did that, and I posted the function. Why was that incorrect?This has been painful to watch. PeroK has been giving excellent advice.
- First, split the integral into two pieces, one where the delta function is zero everywhere and one where it is not.
- Do the inner integral. The first part (above) is zero and the second part (above) sets s = -a. The only q left should be inside the sinh.
- Set a new variable r = q + a. Set you limits in terms of r.
- Do the outer (and only remaining) integral. I believe you will have only one a left.