Results 1 to 2 of 2

Math Help - Derivative, Chain Rule Problem. Help Plz!!

  1. #1
    Newbie
    Joined
    Nov 2009
    Posts
    15

    Derivative, Chain Rule Problem. Help Plz!!

    The question is asking to find the first derivative of the composition (fogoh)(x). Given:

    f(x) = \sqrt{x^2-1}
    g(x) = (x^3+5)^{17}
    h(x) = \frac{2}{x}

    Computing for the derivatives I got:

    f'(x) = \tfrac{1}{2}(x^2-1)^{\frac{-1}{2}}(2x)
    g'(x) = 17{(x^3+5)}^{16}(3x)
    h'(x) = -2(2x)

    I understand that the derivative of f(g(h(x))) = [f'(g(h(x)))].[g'(h(x))].[h'(x)] so I just need to plug the functions but I am not getting the right answer. Can someone please take me through the process step by step so I can see where I went wrong? I understand this is a long question but it would be greatly appreciated! Thank you!
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor Calculus26's Avatar
    Joined
    Mar 2009
    From
    Florida
    Posts
    1,271
    f ' is correct but g ' and but h ' aren't


    g= (x^3 + 5)^17

    g ' = 17(x^3 +5)^16 (3x^2)

    h = 2/x = 2x^(-1)

    h' = -2 x^(-2) = -2/(x^2)

    Try it now
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. chain rule second derivative
    Posted in the Calculus Forum
    Replies: 2
    Last Post: September 13th 2010, 11:35 PM
  2. Derivative chain rule help
    Posted in the Calculus Forum
    Replies: 4
    Last Post: October 19th 2009, 04:27 PM
  3. Replies: 5
    Last Post: October 19th 2009, 02:04 PM
  4. Derivative and Chain Rule HELP!!!!
    Posted in the Calculus Forum
    Replies: 4
    Last Post: March 31st 2008, 07:06 AM
  5. Replies: 2
    Last Post: December 13th 2007, 06:14 AM

Search Tags


/mathhelpforum @mathhelpforum