Results 1 to 2 of 2

Math Help - Solving indefinite series

  1. #1
    Junior Member
    Joined
    Nov 2009
    Posts
    29

    Solving indefinite series

    I dont know how to solve this series with limit of partial sum.

    \sum_{n=1}^{\infty}\frac{1}{(3n-2)(3n+1)}

    Thanx for any help
    Follow Math Help Forum on Facebook and Google+

  2. #2
    is up to his old tricks again! Jhevon's Avatar
    Joined
    Feb 2007
    From
    New York, USA
    Posts
    11,663
    Thanks
    3
    Quote Originally Posted by PJani View Post
    I dont know how to solve this series with limit of partial sum.

    \sum_{n=1}^{\infty}\frac{1}{(3n-2)(3n+1)}

    Thanx for any help
    Hint: this is a telescoping sum

    Note that \frac 1{(3n - 2)(3n + 1)} = \frac 13 \cdot \frac {3n + 1 - (3n - 2)}{(3n - 2)(3n + 1)} = \frac 13 \left( \frac 1{3n - 2} - \frac 1 {3n + 1} \right)

    (instead of using algebraic manipulation as i did above, you can use partial fractions)
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Need help solving indefinite integral...
    Posted in the Calculus Forum
    Replies: 0
    Last Post: July 19th 2011, 11:45 AM
  2. solving an indefinite integral
    Posted in the Calculus Forum
    Replies: 3
    Last Post: May 23rd 2011, 03:27 AM
  3. Replies: 3
    Last Post: April 5th 2009, 11:29 AM
  4. Replies: 3
    Last Post: April 5th 2009, 11:14 AM
  5. Solving This Indefinite Integral
    Posted in the Calculus Forum
    Replies: 1
    Last Post: April 5th 2009, 10:11 AM

Search Tags


/mathhelpforum @mathhelpforum