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: A simple integral?

  1. Dec 9, 2007 #1
    A simple integral?!?

    1. The problem statement, all variables and given/known data

    Integrate 1/(K+ x^2)^(3/2) dx

    2. Relevant equations



    3. The attempt at a solution

    substitution of some kind - if it had an x on top it would be fine...
     
  2. jcsd
  3. Dec 9, 2007 #2

    arildno

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    Dearly Missed

    Set [tex]x=\sqrt{K}Sinh(u)[/tex] and proceed.
     
  4. Dec 9, 2007 #3

    HallsofIvy

    User Avatar
    Science Advisor

    arildno loves that hyperbolic substitution!

    Myself, I would have immediately thought that "[itex]tan^2(\theta)+ 1= sec^2(\theta)[/itex]" and used the substitution [itex]x= \sqrt{K}tan(\theta)[/itex]. I suspect it is just a matter of taste.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook