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: How to integrate int x/(x^2+1)dx

  1. Dec 11, 2009 #1
    [tex]\int{\left(\frac{x}{x^2 + 1}\right)\,dx}[/tex]

    how to integrate?
    i know [tex]\int{\left(\frac{1}{x^2 + 1}\right)\,dx}[/tex]
    is tan^-1 x + C

    how am i going to start answering this question
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Dec 11, 2009 #2

    rock.freak667

    User Avatar
    Homework Helper

    Re: Integration

    try substituting u=x2+1, du=?
     
  4. Dec 11, 2009 #3
    Re: Integration

    meaning.. i should u integration by substitution?
     
  5. Dec 11, 2009 #4
    Re: Integration

    Yes, try the u substitution.
     
  6. Dec 11, 2009 #5
    Re: Integration

    got it..
    1/2 ln |x^2 + 1| + C

    correct?
     
  7. Dec 11, 2009 #6
    Re: Integration

    That's right. One thing though: since x2 + 1 is always greater than 0, no absolute values are needed.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook