# How do you find the sum of the infinite geometric series 1/3+1/9+1/27+1/81+...?

##### 1 Answer

Dec 9, 2015

#### Explanation:

Formula for sum of infinite geometric series is

We have a geometric series :

First we know

Second: Identify

Substitute into the formula

#= (1/3) /(2/3) #

#=(1/3)*(3/2)#

#Soo= 1/2#