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Math Help - Infinite Series

  1. #1
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    Infinite Series

    lim cos[pie]n/2
    n-[inf]

    does converges? If it does what is the limit?
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    Quote Originally Posted by homerb View Post
    lim cos[pie]n/2
    n-[inf]

    does converges? If it does what is the limit?
    Are you doing \lim_{n\to\infty}\cos\frac{\pi n}2?

    What is the cosine of a multiple of \frac\pi2? Look at the unit circle: if n is odd, you get 0, and for even n the value alternates between 1 and -1.

    Is the sequence approaching a single finite value?
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  3. #3
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    Yes it goes to infinite
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    Quote Originally Posted by homerb View Post
    Yes it goes to infinite
    Huh? I said finite value. And anyway, would you mind explaining how the cosine function, which has a range of [-1,1], can reach infinity?
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