1. The problem statement, all variables and given/known data the integral of 1/(1+x^4) from -infinity to +infinity 2. Relevant equations Residue theorem. 3. The attempt at a solution 1/(1+z^4) so z^4 = -1 I know I should be using the residues at z = -sqrt(i) and z= i*sqrt(i) I am getting a complex number as an answer which makes no sense residue at z = -sqrt(i) = 1/(4*i*sqrt(i)) and at z = i*sqrt(i) = 1/(4*sqrt(i)) and therefore integral of (1/1+z^4) = 2pi*i* sum of those residues Am I on the right track?