# For which numbers is this convergence?

1. Jan 22, 2008

### venke

Hi,

I need to know for which nubers of x the serie is convergence.

Is this possible whith d'Alombert? I have tried, but with no result.

Greets,
venke

2. Jan 22, 2008

### mathman

Your series is an infinite geometric series with a=x/(x+1). This series converges for |a|<1. You should be able to find what is the range of x for convergence.