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Homework Help: Sequence and series

  1. Dec 9, 2011 #1
    1. The problem statement, all variables and given/known data
    find the sum of the series to 'n' terms
    (1^3 / 1 ) + (1^3 + 2^3 / 1+2 ) + (1^3 + 2^3 + 3^3 / 1+2+3 ) +......


    2. Relevant equations

    sigma n^2 = n(n+1)(2n+1) / 6
    sigma n = n(n+1) / 2


    3. The attempt at a solution
    numerator = 1^3 + 2^3 + ....... n^3
    denominator = 1+2+3+.......n
    .....
    my answer comes out to be n(n+1) / 2 , but i think thats wrong...
    please lead me
     
  2. jcsd
  3. Dec 9, 2011 #2
    That is the last term you are calculating. And anyway, the question says Sum of cubes (not squares) in numerator. If you evaluate first few terms, you get 1+3+6+10+15+......
    I think you can work this out.
     
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