Results 1 to 3 of 3

Math Help - integral

  1. #1
    Junior Member
    Joined
    Jan 2009
    Posts
    46

    Question integral

    integral
    cosx/(1+ sin^2x) dx

    any help pls?
    i dont know how did we get
    arc tan (sin x) as a result
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor Calculus26's Avatar
    Joined
    Mar 2009
    From
    Florida
    Posts
    1,271
    Let u sin(x) then du = cos(x) dx

    you obtain integral ( du/(1+u^2)) = arctan(u) + C = arctan(sin(x))+C
    Follow Math Help Forum on Facebook and Google+

  3. #3
    MHF Contributor
    Joined
    Oct 2005
    From
    Earth
    Posts
    1,599
    alex83 - You have posted a few of the same types of problems with trig integrals. Why don't you try to finish one and understand it completely before asking for help on another? Do you get the basic concepts behind these? I want you to be able to do them on a test without our help is all.
    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