1. Limited time only! Sign up for a free 30min personal 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!

Homework Help: Sum of a geometric series

  1. Dec 14, 2011 #1
    1. The problem statement, all variables and given/known data
    I already counted [tex]V_{0}=-1[/tex]

    and [tex]q=\frac{1}{3}[/tex]

    given: [tex]V_{n}=1-\frac{2}{U_{n}}[/tex]





    2. Relevant equations

    count: [tex]\sum_{k=0}^{n}V_{k}[/tex]


    3. The attempt at a solution


    i counted the sum and i got : [tex]((\frac{1}{3})^{n+1}-1)(\frac{2}{3})[/tex]

    is that correct?
     
  2. jcsd
  3. Dec 14, 2011 #2

    Simon Bridge

    User Avatar
    Science Advisor
    Homework Helper

    What is Un ... don't make us make assumptions.
     
  4. Dec 15, 2011 #3
    I got it anyway. It's


    [tex]S=-\frac{3}{2}(1-(\frac{1}{3})^{n+1})[/tex]
     
  5. Dec 15, 2011 #4

    Simon Bridge

    User Avatar
    Science Advisor
    Homework Helper

    Well done.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook