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Prove the Power Rule

  1. Sep 11, 2005 #1
    Ok guys, I'm new here and I need some help with a math problem...

    The problem asks me to prove the power rule ---> d/dx[x^n] = nx^(n-1) for the case in which n is a ratioinal number...

    the one stipulation is that I have to prove it using this method: write y=x^(p/q) in the form y^q = x^p and differentiate implicitly...assume that p and q are integers, where q>0.

    Thanks for any help

  2. jcsd
  3. Sep 11, 2005 #2


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    Would I be correct in guessing that we are allowed to assume that the power rule holds for integers? If so, then it is simply a matter of differentiating both sides of the equation [tex]y^q=x^{p}[/tex] and then solving for y'. Where are you stuck?
  4. Sep 11, 2005 #3


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    Don't multiple post.
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