Results 1 to 3 of 3

Math Help - Integration by parts

  1. #1
    Newbie
    Joined
    Feb 2009
    Posts
    10

    Integration by parts

    Sorry to be back so soon, I am once again having problems with integration. The integration problem is x*cos^2[x], I am not sure whether to start with integration by parts first, or if there is a trigonometric integral that specifically relates to problems like this. Any help would be appreciated, thanks!
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    skeeter's Avatar
    Joined
    Jun 2008
    From
    North Texas
    Posts
    12,115
    Thanks
    992
    Quote Originally Posted by MikeDube View Post
    Sorry to be back so soon, I am once again having problems with integration. The integration problem is x*cos^2[x], I am not sure whether to start with integration by parts first, or if there is a trigonometric integral that specifically relates to problems like this. Any help would be appreciated, thanks!
    power reduction identity ...

    x\cos^2{x} = x\left(\frac{1 + \cos(2x)}{2}\right)

    \frac{1}{2}\int x \, dx + \frac{1}{2}\int x\cos(2x) \, dx

    parts for the second integral
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Feb 2009
    Posts
    10

    Thanks

    Thanks a ton, it seems these integrals are much easier than I am making them out to be as long as you know the identities
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 2
    Last Post: January 11th 2012, 03:30 PM
  2. Replies: 8
    Last Post: September 2nd 2010, 01:27 PM
  3. Replies: 0
    Last Post: April 23rd 2010, 04:01 PM
  4. Integration by Parts!
    Posted in the Calculus Forum
    Replies: 7
    Last Post: January 22nd 2010, 04:19 AM
  5. Replies: 1
    Last Post: February 17th 2009, 07:55 AM

Search Tags


/mathhelpforum @mathhelpforum