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Homework Help: Problem on finding second derivative.

  1. Feb 26, 2005 #1


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    I have a problem on finding the second derivative for this function:

    [tex] \frac {x}{x^2-4} [/tex]

    For the first derivative, I got:

    [tex] \frac {-x^2-4}{(x^2-4)^2} [/tex]

    Now here is where I am stuck! So far for the second derivative, I got this (Please check!):

    [tex] \frac {-2x(x^2-4)^2-4x(-x^2-4)(x^2-4)}{(x^2-4)^4} [/tex]

    I need the second derivative simplified! I know, it's an easy question. I may have lost my mind! :rofl:
    Also please explain. Thanks!

    BTW. I am new to this forum and just learned the latex system. It is very complicated. Took me a while just to write out the problems above. I guess I gotta get used to it.
    Last edited: Feb 27, 2005
  2. jcsd
  3. Feb 27, 2005 #2
    Those look good to me. Now all you need to do is simplify. That should be the easy step. You have a factor of [itex] (x^2-4)[/itex] that will divide out. You should be able to get it down to one term.
  4. Feb 27, 2005 #3


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    Is this what you got?:

    [tex] \frac {2x^3+24x}{(x^2-4)^3} [/tex] or [tex] \frac {2x(x^2+12)}{(x^2-4)^3} [/tex]
  5. Feb 27, 2005 #4
    Looks good
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