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 using a specific method

  1. Aug 20, 2012 #1
    1. The problem statement, all variables and given/known data
    I am suppose to rearrange the integral in order to use this formula to solve it:
    ∫f'(x)/f(x)dx=ln|f(x)|+C


    2. Relevant equations
    My integral is ∫(e^x+1)/(e^x+e^-x+2).



    3. The attempt at a solution
    Any help?
     
  2. jcsd
  3. Aug 20, 2012 #2

    DryRun

    User Avatar
    Gold Member

    To simplify the integral, let ##y=e^x## and break it into partial fractions.
     
    Last edited: Aug 20, 2012
  4. Aug 20, 2012 #3
    Write e^(-x) as 1/(e^x). Simplify and you should get the expression:
    [tex]\frac{e^{2x}+e^x}{e^{2x}+2e^x+1}[/tex]
    Can you now see which is f(x) and which is f'(x)?
     
  5. Aug 20, 2012 #4
    this is an easy way to do it

    should get you started at least

    xMu6i.jpg
     
  6. Aug 20, 2012 #5
    pranav got there before me... lol
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook