Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Summing a series on an interval of convergence

  1. May 4, 2010 #1
    1. The problem statement, all variables and given/known data
    Find the interval of convergence of the series and, within this interval, the sum of the series as a function of x.
    2. Relevant equations
    3. The attempt at a solution
    Finding the interval is easy, using the ratio test it reduces down to

    However, I have no idea how to do the second part. Any help?
    Last edited: May 4, 2010
  2. jcsd
  3. May 4, 2010 #2
    1- You should check the end points to decide the interval.
    2- For the sum, I think you know something called "geomtric series", right?
  4. May 4, 2010 #3
    Duh! Thanks.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook