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: Extremely hard integral - pls help

  1. Oct 28, 2012 #1
    1. The problem statement, all variables and given/known data
    integrate the following function: x*√(2x-x2)

    2. Relevant equations

    3. The attempt at a solution
    I substituted x with x=2sin2u. From that I ended up with ∫x*√(2x-x2)= 16∫sin4u*cos2u

    Now I'm supposed to use a formula from an integrals table.. but which?
  2. jcsd
  3. Oct 28, 2012 #2


    User Avatar
    Science Advisor
    Homework Helper

    You should complete the square under the sqrt. [itex] \displaystyle{\sqrt{1-(1-x)^2}}[/itex] and then make the natural substitution.
  4. Oct 28, 2012 #3
    edit: nvm
    Last edited: Oct 28, 2012
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook