1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Integrate 1 / (x^2 - 1)^2

  1. Dec 4, 2012 #1
    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.
     
  2. jcsd
  3. Dec 4, 2012 #2

    arildno

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    Dearly Missed

    Try partial fractions decomposition, remembering that (x^2-1)=(x+1)(x-1)
     
  4. Dec 4, 2012 #3

    Ray Vickson

    User Avatar
    Science Advisor
    Homework Helper

    A more-or-less standard substitution to try out when you see 'x^2-1' is x = cosh(t).
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook