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!

Missing terms of a geometric seqeunce

  1. Jun 5, 2012 #1
    1. The problem statement, all variables and given/known data
    Write the first 5 terms of the geometric sequence
    3, __ , 32x+1, __, __

    2. Relevant equations
    tn=arn-1


    3. The attempt at a solution
    tn=arn-1
    32x+1=3r3-1
    r2=32x+1 / 3
    r=√32x+1 / √3

    I'm stuck
     
  2. jcsd
  3. Jun 6, 2012 #2
    Before taking the square root, try to simplyfy the right side. What is [itex]\frac{3^{2x+1}}{3^{1}}[/itex]?
     
  4. Jun 6, 2012 #3
    Hint:

    If [itex]a,b,c[/itex] are three consecutive terms of a geometric sequence, [itex]b^2 = ac[/itex].
     
  5. Jun 7, 2012 #4
    Ohh I see. 32x+1 / 31 = 32x. And the square root of that is 3x.
    Thank you
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook