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Homework Help: Evaluating the Difference Quotient

  1. Sep 8, 2013 #1
    1. The problem statement, all variables and given/known data
    Evaluate the difference quotient of:
    f(1+h)-f(1) / h
    if f(x)=x3
    and simplify your answer.

    2. Relevant equations

    3. The attempt at a solution
    I took the derivative of x3 to be 3x2 and solved for when x=1 (given from the difference quotient) and got 3, but when I enter the value it's marked incorrect. Not sure what I'm doing wrong, unless I just interpreted the question the wrong way.
  2. jcsd
  3. Sep 8, 2013 #2


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    Calculate [itex]((1 + h)^3 - 1^3)/h[/itex] and do not take the limit [itex]h \to 0[/itex].
  4. Sep 8, 2013 #3
    Ah, okay. Got h^2+3h+3, entered it and it was correct. Thanks! I'm not sure why I thought it was asking for the limit, guess I'm still a little fuzzy from the summer.
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