Results 1 to 2 of 2

Math Help - confussing infinite series problem

  1. #1
    Newbie
    Joined
    Apr 2009
    Posts
    3

    Post confussing infinite series problem

    Hi.

    The problem is giving me a hard time basically because i just can't seem to figure out how to solve for it.

    The problem is \sum(-1)^n\int1/2^x

    the limits on sigma are n=1 to infinity and for the integral its n and n+1
    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 [s]arah View Post
    Hi.

    The problem is giving me a hard time basically because i just can't seem to figure out how to solve for it.

    The problem is \sum(-1)^n\int1/2^x

    the limits on sigma are n=1 to infinity and for the integral its n and n+1
    As in \sum_{n = 0}^\infty (-1)^n \int_n^{n + 1}\frac 1{2^x}??

    Where are you getting stuck? just do the integral, you get

    \sum_{n = 0}^\infty (-1)^{n+1} \frac 1{2^x \ln 2} \bigg|_n^{n + 1}

    now, plug in the limits of integration, factor out the ln(2), and you can split the sum into two geometric series
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Infinite series problem?
    Posted in the Calculus Forum
    Replies: 1
    Last Post: April 18th 2011, 04:33 AM
  2. infinite series problem
    Posted in the Calculus Forum
    Replies: 12
    Last Post: April 1st 2010, 07:33 PM
  3. Infinite Series Problem
    Posted in the Calculus Forum
    Replies: 4
    Last Post: March 16th 2010, 07:00 PM
  4. Infinite series problem
    Posted in the Calculus Forum
    Replies: 3
    Last Post: March 2nd 2010, 09:02 AM
  5. Infinite Series Problem
    Posted in the Calculus Forum
    Replies: 6
    Last Post: April 5th 2008, 12:39 PM

Search Tags


/mathhelpforum @mathhelpforum