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Homework Help: How is sin(npi/2) = (-1)^((n-1)/2) for odd n?

  1. Sep 19, 2009 #1
    I know the MacLaurin series for sin(x) but can't figure out how this reduces to the above (if it does).
  2. jcsd
  3. Sep 19, 2009 #2
    sin(npi/2) is going to be equal to -1 or 1, depending on the value of n, right? So the formula seems plausible. You could prove it through induction.
    Last edited: Sep 19, 2009
  4. Sep 19, 2009 #3
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