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

##### 1 Answer

Feb 22, 2016

The formula for sum of an infinite geometric series is

#### Explanation:

We must first find the common ratio, r, which can be found by using the formula

a is the first term, 1.

The sum is

Hopefully this helps!