Hey wesleybrown.
Hint: Consider that for Riemann integrals that the integral of [a,b] = Integral of (a,b] in terms of the domain of integration.
So embarassing, I am stuck again. This time is on 2c. I ve seen people doing it by complex plane, but I don’t think my instructor want to see that. By double integral, I have gone as far as pluging in infinity to the antiderivative I obtained, and it turns out to be a sin(infinity). Need help again...