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

Does this series converge

  1. Oct 17, 2007 #1

    I want to calculate the sum of this series, but it seems not to converge.
    Can anyone help me

    Thank you.
  2. jcsd
  3. Oct 17, 2007 #2

    matt grime

    User Avatar
    Science Advisor
    Homework Helper

    It does converge, the sum is

    [tex]\sum_{n=1}^{\infty} \frac{1}{n!2^n}[/tex]

    which is a well known series (what Taylor series do you know?).
  4. Oct 17, 2007 #3
    Thank you, yes it does converge. Could you please tell me how to calculate the sum.
    I should revise some old maths books.
  5. Oct 17, 2007 #4


    User Avatar
    Science Advisor
    Homework Helper

    He did tell you how to calculate the sum:
  6. Oct 19, 2007 #5
    I found it myself. The Taylor expansion of e^x at 1/2. Thanks.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook