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: An integral

  1. Jul 14, 2010 #1
    1. The problem statement, all variables and given/known data

    How to integral this one?

    1/(1+a*cosx)



    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Jul 14, 2010 #2
    In this case, you use wolframalpha.com because the calculation by hand is brutal.

    http://www.wolframalpha.com/input/?i=integrate+(1%2Ba*cos(x))^-1

    Some people think that's cheating, but I think doing the grunt work here would be a waste of time since there's no new insight. From the looks of it, it's just several cumbersome integration by parts with the inverse hyperbolic tangent function.
     
  4. Jul 15, 2010 #3

    hunt_mat

    User Avatar
    Homework Helper

    I would try [tex]t=\tan (\theta /2)[/tex], it's one of the standard ones.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook