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: Integration of a composite function

  1. Jun 18, 2012 #1
    1. The problem statement, all variables and given/known data
    The question I have is a more general one, but one I can't find an anser to since I don't have any access to a book on integration at the moment.

    How do we Integrate a composite function.

    ∫f(g(x)) dx

    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
  3. Jun 18, 2012 #2
    A technique that might work is substitution. But it depends on the specific values of f and g, really.
  4. Jun 19, 2012 #3
    Ok, so that means that there is not general method like for integration, as there is for differentiation?
    Nonetheless thanks!
  5. Jun 19, 2012 #4
    If you have ∫f(g(x))g'(x)dx, then this is equal to the simpler ∫f(u)du. This is the analogue to the chain rule for integrals. I say it in words as, the derivative of the inside must appear outside.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook