Question

How do you find the sum of the infinite geometric series 1.02 + 2.04 + 4.08 + 8.16 +…?

Answer 1

You don't.

Explanation:

You can only find the sum of an infinite geometric series if the ratio between each term is between -1 and 1. Or, with more rigor,

`-1 < r < 1`

In that case the formula for the sum would be

`(a_0 - a_nr)/(1-r)`

Where `a_0` is the first term and `a_n` is the nth term.

If `r` is between -1 and 1, then `a_n` will be so small you can disconsider it and find the infinite sum.