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Homework Help: Confusing Limits

  1. Jun 19, 2011 #1
    1. The problem statement, all variables and given/known data

    1. limh->0 (sqrt(a+h)-sqrt(a))/h
    2. limx->1 (1-sqrt(x))/(1-x)

    2. Relevant equations


    3. The attempt at a solution

    I tried conjugate, etc., but couldn't solve it without L'H's Rule.
  2. jcsd
  3. Jun 19, 2011 #2


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    Using the conjugate will work. What did you get when you tried that?
  4. Jun 19, 2011 #3
    Thanks I got 1/(2)for one and 1/2 for number 2
    Last edited: Jun 19, 2011
  5. Jun 19, 2011 #4

    Char. Limit

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    For the second one, try factoring the numerator like so:

    [tex]1 - x =\left(1 - \sqrt{x}\right)\left(1 + \sqrt{x}\right)[/tex]

    The solution should then become obvious.

    EDIT: And for the first one, multiplying by the conjugate of the numerator is what you need to do.
  6. Jun 20, 2011 #5
    Thanks guys, got them.

    Ignore my comment above this.
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