Results 1 to 2 of 2

Math Help - integral help

  1. #1
    Member
    Joined
    Oct 2008
    Posts
    158

    integral help

    integral from 3pie/4 to pie/2 of (sinx)^5 (cosx)^3dx
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Moo
    Moo is offline
    A Cute Angle Moo's Avatar
    Joined
    Mar 2008
    From
    P(I'm here)=1/3, P(I'm there)=t+1/3
    Posts
    5,618
    Thanks
    6
    Hello,
    Quote Originally Posted by twilightstr View Post
    integral from 3pie/4 to pie/2 of (sinx)^5 (cosx)^3dx
    Note that \cos^3x=\cos^2x\cos x=\cos x(1-\sin^2 x)

    So :
    \int_{3 \pi/4}^{\pi / 2} \sin^5x\cos^3x ~dx=\int_{3 \pi/4}^{\pi/2} \cos x \sin^5x (1-\sin^2x) ~dx

    =\int_{3 \pi/4}^{\pi/2}\cos x\sin^5x ~dx-\int_{3 \pi/4}^{\pi/2} \cos x  \sin^7x ~dx

    Substitute t=\sin(x) in each of the integrals and you're done.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 2
    Last Post: August 31st 2010, 07:38 AM
  2. Replies: 1
    Last Post: June 2nd 2010, 02:25 AM
  3. Replies: 0
    Last Post: May 9th 2010, 01:52 PM
  4. Replies: 0
    Last Post: September 10th 2008, 07:53 PM
  5. Replies: 6
    Last Post: May 18th 2008, 06:37 AM

Search Tags


/mathhelpforum @mathhelpforum