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Math Help - convergent-divergent question

  1. #1
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    convergent-divergent question

    here is the problem:
    an = cos(2/n^2)
    Do I divide top and bottom by n^2 to get cos(0) = 1 ?
    then it converges but I don't feel confident because I am not sure how to do this one, there is no example in the book to compare to.
    Thank you,
    Keith
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  2. #2
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    Quote Originally Posted by keith View Post
    an = cos(2/n^2)
    Do I divide top and bottom by n^2 to get cos(0) = 1 ?
    Do you know that \frac{2}{{n^2 }} \to 0?
    If so, then you know that cos(0)=1.
    That is simply all there is to it.
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  3. #3
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    Just remember what Plato did works here because cosine is a continous function.
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  4. #4
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    Quote Originally Posted by Plato View Post
    Do you know that \frac{2}{{n^2 }} \to 0?
    If so, then you know that cos(0)=1.
    That is simply all there is to it.







    Thank you, it just seemed too simple an answer, I just thought it was wrong.
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