Question

How do you find the sum of the infinite geometric series given `12-18+24-...`?

Answer 1

We use the formula `s_oo =a/(1 - r)` to find the sum of an infinite geometric series. Note that `|r| < 1` for the sum to be finite.

The common ratio, `r`, is given by `r = t_2/t_1 = -18/12 = -3/2`

However, since `|-3/2| > 1`, this series is divergent and hence the sum cannot be found.

Hopefully this helps!