1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    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!

Any way to figure out what this finite geometric series sums to?

  1. Feb 23, 2012 #1
    I would like to find a nice formula for [itex]\sum_{k=0}^{n - 1}ar^{4k}[/itex]. I know that [itex]\sum_{k=0}^{n - 1}ar^{k} = a\frac{1 - r^n}{1 - r}[/itex] and was wondering if there was some sort of analogue.
     
  2. jcsd
  3. Feb 23, 2012 #2

    micromass

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor
    2016 Award

    Use the formula with [itex]r^4[/itex] instead of r.
     
  4. Feb 23, 2012 #3
    Thank you micromass for your help. Wow that was really simple.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Any way to figure out what this finite geometric series sums to?
  1. Sum of geometric series (Replies: 10)

Loading...