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Homework Help: The sequence b(n)= npicos(npi) coverges or diverges?

  1. Sep 15, 2010 #1
    The sequence b(n)= npicos(npi) coverges or diverges? if it converges what is the limit?

    My Work

    When n is even cosnpi= o and b(n)=o (therefore when n is oven it converges)
    but
    when n is odd cosnpi=-1 and b(n)= - infinity( thereofre when n is even it diverges)

    is this correct?
     
    Last edited: Sep 15, 2010
  2. jcsd
  3. Sep 15, 2010 #2
    cos(npi) is never zero. I think you are thing about sin(npi).

    cos(npi) simply osscillates between 1 and -1.
     
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