1. The problem statement, all variables and given/known data integrate dx / (x^2 - 1)^2 2. Relevant equations 3. The attempt at a solution There is nothing i can substitute to get rid of x. Except x=sqr(t), but then dx is 1/2sqr(t) so i get: ∫( dt / (t-1)^2 * 2sqr(t) ) and it's still impossible to integrate.