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 involving complex exponentials

  1. Sep 15, 2014 #1
    1. The problem statement, all variables and given/known data

    [itex]\int[/itex][itex][[/itex]( e^x + 4 )/ (4e^x + 1) [itex]][/itex]^2

    2. Relevant equations

    No substitutions have been given.

    3. The attempt at a solution

    I've tried using the method of f' (x)/f (x). But it was in vain.

    I haven't been able to do it. I don't really know where to start.
    Last edited: Sep 15, 2014
  2. jcsd
  3. Sep 15, 2014 #2


    User Avatar
    Homework Helper

    .. because clearly the numerator is not the derivative of the denominator.

    Consider the substitution [itex]u = e^x[/itex].
  4. Sep 15, 2014 #3
    Actually I was thinking about the substitution. But I have one question; an exponential function is not linear. So if I use substitution does it become a linear one ?
  5. Sep 15, 2014 #4
    No. Your function will become a rational function. You will then be able to integrate it by following the method of partial fractions to separate it into a sum of known integrals.
  6. Sep 15, 2014 #5
    OK thanks.

    I'll start working on it.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted