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!

Integral of type 'derivative over function' with a twist

  1. Nov 26, 2009 #1
    1. The problem statement, all variables and given/known data

    Find the integral

    [(2x - 3) / (x^2 - 3x - 5)^2] dx

    2. Relevant equations

    I noticed that if I differentiate the denominator I get the nominator, which would be a simple problem. The denominator, however is raised to the power 2.

    Can I still somehow use the rule for integrals where the nominator is the derivative of the denominator? Or do I need to take a different approach?

    Thank you
     
  2. jcsd
  3. Nov 26, 2009 #2

    Dick

    User Avatar
    Science Advisor
    Homework Helper

    The 'approach' you are talking about is integration by substitution, I hope. You've observed that if u=x^2-3x-5, then du=u'dx=(2x-3)dx. That's great. That turns the integral into du/u^2 in terms of u. Can you integrate that?
     
  4. Nov 26, 2009 #3
    I got it, thanks an awful lot!
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Integral of type 'derivative over function' with a twist
Loading...