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Homework Help: Is rationalizing the denominator an option

  1. Jun 13, 2013 #1
    1. The problem statement, all variables and given/known data
    Evaluate x-> 3 for (x^3-27)/(x-3) by as many methods as you can think of.

    2. Relevant equations

    3. The attempt at a solution
    I could only think of one:

    1) (x-3)(x^2+3x+9)/(x-3)= (x^2+3x+9)
    3^2 + 3(3) + 9= 27

    What other methods can I do? Is rationalizing the denominator an option, even if it is redundant? Thank you.
  2. jcsd
  3. Jun 13, 2013 #2


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    Science Advisor
    Homework Helper

    The denominators already rational. Do you know l'Hopital's rule?
  4. Jun 13, 2013 #3
    Yes, I do! Why didn't I think of that? :tongue: Thank you very much.
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