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Math Help - Series Problem

  1. #1
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    Series Problem

    How do you find the sum of sum from n=0 to infinity of (n(-2)^n)/(2^n).

    Do I use alternating series test and geometric series?
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  2. #2
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    Re: Series Problem

    Quote Originally Posted by Preston019 View Post
    How do you find the sum of sum from n=0 to infinity of (n(-2)^n)/(2^n).
    Do I use alternating series test and geometric series?
    Note that (-2)^n=(-1)^n2^n so n\frac{(-2)^n}{2^n}=(-1)^nn
    So what?
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  3. #3
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    Re: Series Problem

    Quote Originally Posted by Plato View Post
    Note that (-2)^n=(-1)^n2^n so n\frac{(-2)^n}{2^n}=(-1)^nn
    So what?
    It's divergent, right?
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  4. #4
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    Re: Series Problem

    Yes, any series with terms that do not go to 0 is divergent.
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