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Homework Help: Quick derivative

  1. Dec 5, 2004 #1
    hey guys,

    I need to find the derivative of this function, do i use the chain rule and the product rule? and for the stuff inside the parenthesis, how do i differentiate that? the derivative of x is just 1....but since its a fraction, would it be as simple as that? please help, thanks.

    [tex]\frac{1}{32} \left( \frac{64}{x} + \frac{x}{50} \right) * 1.60[/tex]
  2. jcsd
  3. Dec 5, 2004 #2


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    Write it as a sum:[itex] 3.2x+\frac{1}{1000x} [/itex] and use the derivatives of "x" and "1/x" to find your result.
  4. Dec 5, 2004 #3


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    mmh.. all you need is the property [ k*f(x) ]' = k*f '(x) for any constant k.

    In your case,

    [tex]\frac{1}{32} \left( \frac{64}{x} + \frac{x}{50} \right) * 1.60 = \frac{1.60}{32}\left( \frac{64}{x} + \frac{x}{50} \right) = \frac{1.60}{32}\left( \frac{64}{x} \right) + \frac{1.60}{32}\left(\frac{x}{50} \right) = \frac{1.60*64}{32}\left( \frac{1}{x} \right) + \frac{1.60}{32*50}\left(x \right)[/tex]

    and 1/x is the same as [itex]x^{-1}[/itex]. And you know what the derivative rule is for [tex]x^k[/itex] where k is a constant.
  5. Dec 5, 2004 #4
    Great, thanks a lot guys, i appreciate it.
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