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Using L'hopital's rule in exponential function

  1. Feb 29, 2012 #1
    Is that any way to find a finite value which is not equal to zero using L'hopital's rule in


    i kept getting 0/0 after differentiation

    Thank you
  2. jcsd
  3. Feb 29, 2012 #2


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    So your problem is
    [tex]\lim_{z\to -ia}\frac{e^{-A/(z+ ia)}}{(z+ia)^2}[/tex]
    Instead, write the exponential as a Laurent series around -ia. It should be clear that you will have a "1" as the constant term and so the limit will not exist. This function has a pole of order 2 at z= -ia.
    Last edited by a moderator: Mar 1, 2012
  4. Mar 1, 2012 #3
    Thank you very much HallsofIvy....i got what u meant..
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