but how can we find r? It seems like somebody said to divide one term in the series by the one before. But doing so doesn't come out to

Here is the formula for :

What would go in the numerator and denominator, in this case?

Anyhow since then the geometric series does NOT diverge

But here is another question. Now, we have to find the sum. Is it possible that, after this point, the series could diverge?

- The infinite series converges. But what does this have to do with the sum?