# Summation identities

1. Sep 5, 2009

### killerfish

Hi guys,

sry if i asked a silly qns. Is the below equivalent is true???

2. Sep 5, 2009

### jgens

No, that's not correct. Using your limits of summation you should have:

$$\sum_{i = 0}^{n-1} i = \frac{n(n-1)}{2}$$