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: (e^-2x) / (1+e^-x) integral

  1. Apr 15, 2004 #1
    just wonder if someone could help me solve this integral,
    thanks

    (e^-2x) / (1+e^-x)
     
  2. jcsd
  3. Apr 15, 2004 #2
    Can you integrate (t2) / (1 + t)? I'm guessing that's how you should do it, since I don't really know... :tongue:
     
  4. Apr 15, 2004 #3
    Do some algebraic manipulation of the original problem. If you do, the problem wil reduce to a form that allows U substitution.
     
  5. Apr 16, 2004 #4
    I think Chen was on the right track, ie, use substitution t = e^-x
    but don't forget about dx -- should come to a much simpler integration
     
  6. Apr 18, 2004 #5
    k..substitute u = (1 + e^-x)......then find du.....work from there....and you should get the correct answer.....
    ....hint.....remember that u-1 = e^-x....
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook