# Alternating Series

1. Feb 1, 2010

### seanhbailey

1. The problem statement, all variables and given/known data
What is $$\sum_{n=1}^{\infty} (-1)^n/n$$

2. Relevant equations

3. The attempt at a solution
I know that the alternating series $$\sum_{n=1}^{\infty} (-1)^{n-1}/n$$ converges to ln(2), but I am not sure how to find this series.
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. Feb 1, 2010

### Bohrok

(-1)n-1 = (-1)n(-1)-1 = -1*(-1)n
then you can take the constant -1 outside the sum.