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Math Help - Derivative help

  1. #1
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    Derivative help

    D_r (\frac{2r+3}{3r-2})
    Last edited by ^_^Engineer_Adam^_^; December 1st 2006 at 09:12 PM. Reason: wrong type
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  2. #2
    Grand Panjandrum
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    Quote Originally Posted by ^_^Engineer_Adam^_^ View Post
    D_r (\frac{2r+3}{3r-2})
    You need the quotient rule:

    D_r \frac{f(r)}{g(r)}=\frac{g(r)f'(r)-f'(r)g(r)}{[g(r)]^2}

    here:

    f(r)=2r+3,

    f'(r)=2,

    g(r)=3r-2,

    g'(r)=3

    so:

    D_r \left( \frac{2r+3}{3r-2} \right)=\frac{g(r)f'(r)-f(r)g'(r)}{[g(r)]^2}<br />
=\frac{2(3r-2)-3(2r+3)}{(3r-2)^2}=-\frac{13}{(3r-2)^2}<br />

    RonL
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  3. #3
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    Quote Originally Posted by CaptainBlank View Post
    so:

    D_r \left( \frac{2r+3}{3r-2} \right)=\frac{g(r)f'(r)-f(r)g'(r)}{[g(r)]^2}<br />
=\frac{2(3r-2)-3(2r+3)}{(3r-2)^2}=-\frac{13}{(3r-2)^2}<br />
    I see you learned the quotient rule!
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  4. #4
    Grand Panjandrum
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    Quote Originally Posted by ThePerfectHacker View Post
    I see you learned the quotient rule!
    I'm afraid not; I derived it.

    RonL
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