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Homework Help: Series homework problem help

  1. May 12, 2009 #1
    1. The problem statement, all variables and given/known data
    Using Comparison test and LCT, determine whether it is convergent or divergent:

    (summation n=1 to infinity) sqrt(n+2)/(2n^2+n+1)

    2. Relevant equations

    3. The attempt at a solution
    i compared it with sqrt(x)/2n^2 which is 1/2n^(3/2)
    and then the answer showed something weird...they had to plug in a number (e.g. 1) which reversed the inequality sign... to sqrt(n+2)/(2n^2+n+1) is larger than 1/2n^(3/2)...does anyone know why?
  2. jcsd
  3. May 12, 2009 #2


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    Science Advisor
    Homework Helper

    Re: Series

    Then pick a different comparison. You want to make the numerator larger and the denominator smaller if you think it converges. Be creative! How about comparing with sqrt(n+n)/(2n^2)?
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