# summation notation

• October 1st 2009, 06:22 AM
LovesMeTrike
summation notation
How would I go about writing $1/2-1/3+1/4-1/5+1/6$ in summation notation?
• October 1st 2009, 06:24 AM
pomp
Quote:

Originally Posted by LovesMeTrike
How would I go about writing $1/2-1/3+1/4-1/5+1/6$ in summation notation?

$\sum_{n=2}^6 \frac{(-1)^n}{n}$

The $(-1)^n$ term gives the alternating signs.