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Homework Help: Behaviour of Gamma function when z = -n

  1. Dec 9, 2012 #1
    Hi there,

    I'm actually trying to understand why the behaviour of the Gamma function at z = -n is

    (-1)^n/(n!z) + O(1)

    The first term (although without the z) I recognized it as the residue of f when z= -n. But the rest, no idea. Any explanation is very appreciated.
  2. jcsd
  3. Dec 10, 2012 #2


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    Homework Helper

    Where are you getting that asymptotic expression? Why does it involve both n and z? The Gamma function diverges at the negative integers; are you looking for an expansion of the Gamma function when z is close to a negative integer?
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