Question

How do you find the sum of the infinite geometric series 3-1+1/3...?

Answer 1

From 3 to -1 to 1/3, what would the common ratio be?

Well, it seems as if we are multiplying by `-1/3` because from 3 to -1 would be `3*-1/3` and from -1 to 1/3 would be `-1*-1/3`

From here, we can just apply the infinite series formula, `1/(1-r)` because the r is between -1 and 1.

Thus, the sum is `1/(1-(-1/3))` or `1/(1+1/3)` or `1/(4/3)`

or `3/4`