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: I forgot how to do this integration Help

  1. Jul 5, 2011 #1
    1. The problem statement, all variables and given/known data

    Do the integration

    2. Relevant equations


    3. The attempt at a solution

    I forgot how to do this integration with another method. I think I can do it through Trigonometric Method. But I remember that there is still another way to do it without using Trigonometric Method. Anyone can show me steps to do it? Thanks.
  2. jcsd
  3. Jul 5, 2011 #2
    Well, for the trig method you would use the substitution let x = ytan(u)
    If that gets you the right answer then why bother with another method. I can't think of a different method right now that would work.
  4. Jul 5, 2011 #3


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member

    Take the derivative of [itex]\displaystyle \frac{x}{y^2\sqrt{x^2+y^2}}\,,[/itex] treating y as a constant, of course. Then see if you can reverse the process.
  5. Jul 5, 2011 #4


    User Avatar
    Science Advisor
    Homework Helper

    Try a substitution [itex] x=y \sinh t [/itex]. The resulting integration will be trivial.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook