- #1

- 170

- 2

## Homework Statement

Determine whether the serie is convergent or divergent , if it is convergent find its sum.

Ʃ

^{∞}

_{n=1}(1 + 2

^{n})/ 3

^{n}

## Homework Equations

Ʃa(r)

^{n-1}= a / (1-r) r < 1 is converging or if r > 1 diverging

## The Attempt at a Solution

Well I can see its a geometric series so i did Ʃ (1/3)^n + (2/3)^n and r < 1 therefore its convergent but I can't figure out the a. I thought it would be one but the answer key says 1/3 and 2/3 as the a for both series