Use residues! For an entertaining narrative with the correct answer, see here. For a derivation, see a complex analysis text.
###Added Here's a link to an outline of the residue method of solving this: Conway page 122.
Use residues! For an entertaining narrative with the correct answer, see here. For a derivation, see a complex analysis text.
###Added Here's a link to an outline of the residue method of solving this: Conway page 122.