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Homework Help: Trouble with Quotient Rule

  1. Dec 3, 2012 #1
    1. The problem statement, all variables and given/known data
    Differentiate (-sqrt(1 + x^2)) / x

    2. Relevant equations
    [f'(x)g(x) - f(g)g'(x)] / [g(x)]^2

    3. The attempt at a solution

    I need to simplify it further, but before I do I checked it into Mathematica and it says the derivative is incorrect. What did I do wrong?
  2. jcsd
  3. Dec 3, 2012 #2


    Staff: Mentor

    What you did looks fine. It might be that what you typed into Mathematica isn't right. Or maybe Mathematica is just giving you the same thing in a different form. Try factoring (x2 + 1)-1/2 out of the two terms in the numerator.
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