Results 1 to 2 of 2

Thread: More fun conceptual stuff :(

  1. March 21st 2010, 09:57 PM #1
    Selim
    Selim is offline
    Junior Member Selim's Avatar
    Joined
    Feb 2010
    Posts
    38

    More fun conceptual stuff :(

    Given cos(x)= \frac{1-u^2}{1+u^2} then

    u^2=

    sin(x)= u

    dx=
    Follow Math Help Forum on Facebook and Google+
  2. March 21st 2010, 10:49 PM #2
    ione
    ione is offline
    Member
    Joined
    Feb 2010
    Posts
    148
    Thanks
    2
    Quote Originally Posted by Selim View Post
    Given cos(x)= \frac{1-u^2}{1+u^2} then

    u^2=\frac{1-cos(x)}{1+cos(x)}

    sin(x)=\frac{2u}{1+u^2}

    dx=\frac{2\,du}{1+u^2}
    u=\frac{sin(x)}{1+cos(x)}=tan({\frac{x}{2}})

    These are the substitutions that were used for \int\frac{1}{3+2cos(x)}\,dx
    Last edited by ione; March 21st 2010 at 10:59 PM.
    Follow Math Help Forum on Facebook and Google+
« Tough Calculus Integral problem | Numerical methods help »

Similar Math Help Forum Discussions

  1. 5 CONCEPTUAL problems I need help with, thank you.
    Posted in the Calculus Forum
    Replies: 3
    Last Post: July 27th 2011, 10:58 AM
  2. [SOLVED] Conceptual DE question.
    Posted in the Differential Equations Forum
    Replies: 0
    Last Post: February 9th 2011, 12:22 PM
  3. Conceptual Integrals
    Posted in the Calculus Forum
    Replies: 3
    Last Post: February 25th 2010, 11:12 AM
  4. Various conceptual questions
    Posted in the Differential Geometry Forum
    Replies: 2
    Last Post: March 29th 2009, 09:43 PM
  5. Partly Conceptual
    Posted in the Calculus Forum
    Replies: 1
    Last Post: October 20th 2008, 08:48 AM

Search Tags


/mathhelpforum @mathhelpforum