Results 1 to 2 of 2

Math Help - integration

  1. #1
    Newbie
    Joined
    Oct 2009
    Posts
    15

    integration

    Hi, in my lecture notes it says:

    \int^9_0 2x cos x^2 dx

    equals to

     sin x^2 ]^9_0

    i dont get how they got that

    can someone please explain it to me in a very simple way?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member
    Joined
    Jun 2009
    Posts
    806
    Thanks
    4
    Quote Originally Posted by Pengu View Post
    Hi, in my lecture notes it says:

    \int^9_0 2x cos x^2 dx

    equals to

     sin x^2 ]^9_0

    i dont get how they got that

    can someone please explain it to me in a very simple way?
    Put x^2 = t, then
    2x*dx = dt.
    The integration becomes
    Int(cost)dt = sin(t) = sin(x^2)
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 3
    Last Post: November 3rd 2010, 12:54 AM
  2. Replies: 2
    Last Post: November 2nd 2010, 04:57 AM
  3. Replies: 8
    Last Post: September 2nd 2010, 12:27 PM
  4. Replies: 2
    Last Post: February 19th 2010, 10:55 AM
  5. Replies: 6
    Last Post: May 25th 2009, 06:58 AM

Search Tags


/mathhelpforum @mathhelpforum