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Homework Help: Series error

  1. Nov 13, 2008 #1
    How many terms of the series do we need to add in order to find the sum to the indicated accuracy?

    The alternating series from n=1 to infinity of ((-1)^(n+1))/(n^2)
    |error| less than 0.0399

    i got it down to 1/n^2 is less than 0.0399 but i can't figure out if n = 5 or n=6... please help:(
    Last edited: Nov 13, 2008
  2. jcsd
  3. Nov 13, 2008 #2


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    Science Advisor

    If you want 1/n2< 0.0399, then you want 1/0.0399= 25.0626< n2 While it is close hat is NOT true for n= 5.
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