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: Integration problem

  1. Feb 18, 2007 #1
    1. The problem statement, all variables and given/known data

    (integrate: upper limit 3; lower limit 1)(dx/((x^(1/2))(x+1))

    2. Relevant equations



    3. The attempt at a solution

    First of all, somebody needs to show me how to get the actual integration sign to show up on the forums.

    Anyway, I was pretty confused with this one. I tried making u be x+1 and du=dx, but I was afraid this wouldn't solve for the radical x that I also had. Than I tried making u be x and du be dx, but then that wouldn't solve for the x+1 that I had. I don't think I can break this up into two different equations, so I'd like some help.
     
  2. jcsd
  3. Feb 19, 2007 #2
    First line of attack in such cases: Remove the radical with a "square". Try x = u2.

    Btw, making the "substitution" x = u does nothing more than change the letter denoting the dummy variable.

    As for getting LaTeX to work, see this thread: https://www.physicsforums.com/showthread.php?t=8997
     
  4. Feb 19, 2007 #3

    Gib Z

    User Avatar
    Homework Helper

    After trying that x=u^2 substitution, try integration by parts.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook