Results 1 to 2 of 2

Math Help - Trignometric Integrals

  1. #1
    Junior Member
    Joined
    Aug 2011
    Posts
    37

    Trignometric Integrals

    Hey, so i did this problem and got -8/15, but then answer at the back was positive 8/15. Can someone help me out?
    Thanks in advance! (You have to click on the photo twice to rotate it upright)
    Attached Thumbnails Attached Thumbnails Trignometric Integrals-2013-02-21-15.09.28.jpg  
    Last edited by Dragon08; February 21st 2013 at 01:12 PM.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Junior Member EliteAndoy's Avatar
    Joined
    Feb 2013
    From
    United States
    Posts
    56
    Thanks
    3

    Re: Trignometric Integrals

    You changed the bound of the integral wrong hehe. When u=cosx, then your lower bound with respect to u is 1 and upper bound is zero. Always remember that \int_{1}^{0} =-\int_{0}^{1} so you have to use a property of integral to make the lower bound 0 and upper bound 1, but you have to multiple the integral by -1. That will cancel out your negative and you will get 8/15.
    Last edited by EliteAndoy; February 21st 2013 at 09:04 PM.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. trignometric identities
    Posted in the Trigonometry Forum
    Replies: 6
    Last Post: November 24th 2011, 05:56 AM
  2. Trignometric Integrals
    Posted in the Calculus Forum
    Replies: 5
    Last Post: February 11th 2010, 09:48 PM
  3. Trignometric Integrals
    Posted in the Calculus Forum
    Replies: 9
    Last Post: February 9th 2010, 08:02 PM
  4. Trignometric Integrals
    Posted in the Calculus Forum
    Replies: 2
    Last Post: February 6th 2010, 05:11 PM
  5. trignometric integrals
    Posted in the Calculus Forum
    Replies: 3
    Last Post: January 31st 2009, 02:56 PM

Search Tags


/mathhelpforum @mathhelpforum