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!

Sums/Series, basic algebra ?

  1. Apr 20, 2008 #1
    [tex]\sum[/tex] (2^(2n)-(-7)^n)/(11^n)

    The book has that expression equal to
    [tex]\sum[/tex] (4/11)^n - [tex]\sum[/tex] (-7/11)^n

    I'm not seeing how the first part changes to (4/11)^n. Wouldn't it be (2^2+2^n) & not 4^n? Or is there something else I'm missing?
     
  2. jcsd
  3. Apr 20, 2008 #2

    nicksauce

    User Avatar
    Science Advisor
    Homework Helper

    Fact:
    [tex](x^y)^z = x^{yz}[/tex].
    Does that help you out?
     
  4. Apr 20, 2008 #3
    Crude, nm. 2am & math doesn't mix sometimes. ^_^
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Sums/Series, basic algebra ?
  1. Sum of Series (Replies: 10)

  2. Sum of a series (Replies: 11)

  3. Sum of a series (Replies: 15)

  4. The sum of a series (Replies: 4)

Loading...