Results 1 to 4 of 4

Math Help - hyperbolic functions

  1. #1
    Newbie
    Joined
    Mar 2008
    Posts
    16

    hyperbolic functions

    Can anybody help me here?

    Use hyperbolic functions to find the value of...
    The integral of 1/square root of(16x^2 - 36) dx (between the values 12 and 6)
    my working so far is....
    4x=6cosh(u) 4dx/du=6sinh(u)
    (16x^2-36=36coshu^2 - 36)
    with all the subtituation i get to the integral of 1.5sinh(u)/6sinh(u) du
    but then i am stuck after this. Sorry this is a bit messy but can anybody help?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Joined
    Aug 2007
    From
    USA
    Posts
    3,111
    Thanks
    2
    \frac{sinh(u)}{sinh(u)} = What?

    I'm temtpted to take off extra points for not seeing it.

    Try to relax a little. No sense missing the simple algebra.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Mar 2008
    Posts
    16
    Yeh but in my example it has
    integral of 1.5sinh(u)/6sinh(u) du= 1/4 intregral of arccosh(2/3x)+C
    i dont understand how this works..
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor
    Joined
    Aug 2007
    From
    USA
    Posts
    3,111
    Thanks
    2
    You're showing signs of stress.

    1) 1.5 is not particularly helpful. 1.5/6 = 3/12 = 1/4

    2) \frac{1}{4}\frac{sinh(u)}{sinh(u)} = \frac{1}{4}

    3) \int \frac{1}{4} du = \frac{1}{4}u + C

    4) You're not going to make me do ALL the work, are you? Look at your original substitution and move #3 back to terms of 'x'.

    5) You seem to have an extra "integral" in that answer.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Hyperbolic Functions
    Posted in the Calculus Forum
    Replies: 5
    Last Post: October 27th 2009, 07:50 PM
  2. Hyperbolic Functions #2
    Posted in the Calculus Forum
    Replies: 1
    Last Post: October 27th 2009, 07:38 AM
  3. Hyperbolic Functions
    Posted in the Calculus Forum
    Replies: 2
    Last Post: November 17th 2008, 06:31 AM
  4. hyperbolic functions!!
    Posted in the Calculus Forum
    Replies: 2
    Last Post: March 11th 2008, 11:29 AM
  5. hyperbolic functions
    Posted in the Calculus Forum
    Replies: 2
    Last Post: January 20th 2007, 03:40 PM

Search Tags


/mathhelpforum @mathhelpforum