Geometric series. Find the sum of the series. Powers.

AI Thread Summary
The discussion focuses on finding the sum of a geometric series defined by the terms 3, 3^(4/3), 3^(5/3), and so on. The initial term (a) is identified as 3, but the common ratio (r) was initially unclear. Participants clarify that the common ratio can be determined by dividing successive terms, leading to a better understanding of the series. Once the common ratio is established, the standard formula for summing the series can be applied. The conversation concludes with the participant expressing gratitude for the assistance received in solving the problem.
NotaPhysicist
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Homework Statement



Find the sum of 9 terms of the series 3 + 3^(4/3) + 3^(5/3) + ...

Homework Equations



I'm just learning sequences and series and senior high school level. I'm finding it hard to apply a, ar, ar^(n-1), ... to this.

a = 3.

I don't know how to find common ratio. I'm confused. Once I know r I can apply the standard formula for summing the series.

The Attempt at a Solution




Any help will be greatly appreciated.
 
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NotaPhysicist said:

Homework Statement



Find the sum of 9 terms of the series 3 + 3^(4/3) + 3^(5/3) + ...

Homework Equations



I'm just learning sequences and series and senior high school level. I'm finding it hard to apply a, ar, ar^(n-1), ... to this.

a = 3.

I don't know how to find common ratio. I'm confused. Once I know r I can apply the standard formula for summing the series.

The Attempt at a Solution


Homework Statement


Homework Equations


The Attempt at a Solution



Any help will be greatly appreciated.

In geometric series, the following term is obtained by multiplying the previous term by the common ratio r. Which, in turn, means that, you can obtain r by dividing the following term by the previous term; like this:

r = \frac{a_2}{a_1} = \frac{a_3}{a_2} = ... = \frac{a_n}{a_{n - 1}}

So, can you calculate the common ratio in the problem above?
 
Yes! I got it now. Thanks for your help!
 

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