1. PF Contest - Win "Conquering the Physics GRE" book! Click Here to Enter
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Finding the sum of 2^n / n!

  1. Aug 5, 2007 #1
    I need to find the sum of 2^n/n! from n=2 to infinity, i know that it converges to e^x but how do i find the sum?
  2. jcsd
  3. Aug 5, 2007 #2
    It is e^2.
    Since x^n/n! sums to e^x substitute x=2 to get answer.
  4. Aug 5, 2007 #3
    Thanks, it was so simple -.-
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook