Hi everyone,

I didn't know where I should post my question as I'm new here; I hope this is the right place. Anyway, my question is:

I need to show that the following integral:

is equal to =

we're also given (i.e. can use)

What is the best contour?

I think the residue will be zero as the function is analytic everywhere but the problem is how to prove that the contours used tend to zero?