1. The problem statement, all variables and given/known data ∫ from infinity to 0 of x^2/(x^2+1)(x^2+16) 2. Relevant equations The Integral will be the sum of the residues times 2πi 3. The attempt at a solution The only singularities that matter are at i and 4i and they are simple poles. So x^2/(x^2+1)/(2x) and I plug in 4i and get -2i/(15) then I plug in i into x^2/(x^2+16)/(2x) and get i/30 and when I add them I get -3i/30. Because it's only from 0 and to negative infinity I mult that by ∏i and I get ∏/10.