Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Stuck on the following integral

  1. Aug 25, 2006 #1
    Hi, I am kinda stuck on the following integral:


    any hints?
  2. jcsd
  3. Aug 25, 2006 #2


    User Avatar
    Homework Helper

    If you let

    y^2 = \frac{{1 + x}}{{1 - x}} \Leftrightarrow x = \frac{{y^2 - 1}}{{y^2 + 1}}

    The integral will become fraction of rationals, losing the square root.
  4. Aug 25, 2006 #3
    so are you saying to substitute that for x?
  5. Aug 25, 2006 #4
    or by making this substitution, the square root will be taken away
  6. Aug 25, 2006 #5
    Or you could do the trig substitution [tex]x = \sin\theta[/tex]
  7. Aug 25, 2006 #6


    User Avatar
    Homework Helper

    Yes, use that substitution to lose the square root.

    I already solved for x as well, which allows you to easily find dx in terms of dy by differentiating both sides.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook