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Homework Help: Convergent or divergent?

  1. Apr 2, 2009 #1
    convergent or divergent??

    1. The problem statement, all variables and given/known data

    i took a calc 2 quiz today and had a question on one of the. it's too late to correct what i did, but it's never too late to learn it for the final haha

    here is the problem
    they want us to find the sum of the series (below) from 1 to infinity (i dont know how to code it so will try my best to represent it)

    E (-1)^n * n/(3n +1)

    i need to find if it is conv or div.
    i jumped straight to test of divergence which states that if the limit of the the function as it approaces infinity of (An) "function" does not approach 0 then it div. i know limit of the
    n/3n+1 is 1/3 so i said that the function diverges but did not know what the (-1)^n did. would that change it any? or was i right?
  2. jcsd
  3. Apr 2, 2009 #2


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    Science Advisor

    Re: convergent or divergent??

    Then look at that test again. Does it say what sign the numbers must be? If I recall correctly, it does not so the (-1)n does not matter.
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