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Homework Help: Interval of convergence.

  1. Oct 5, 2012 #1
    1. The problem statement, all variables and given/known data

    Find the radius and the interval of convergence for the series:

    Ʃ((-1)nxn)/(4nlnn) with sum n=2 to ∞.

    2. Relevant equations

    3. The attempt at a solution

    I'm testing for the left and right side of the interval. I've found that cn=1/(lnn), an=1/4, and R=1. I used the alternating series test to check the left side, ((-1)n)/(ln(n)). It passed the decreasing in magnitude and the terms to 0 test, so converges absolutely. The right side, 1/(lnn) > 1/n, so diverges to infinity by squeeze divergence. So the interval would be [-1,1). I'm pretty confident on everything except for the left and right side convergence. Is it correct?

  2. jcsd
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