zexen_lowe on 24 September 2008
| tombi123 said: Something similar: 0! = 1 |
That's because 1 is the multiplicative identity (i.e. any number multiplied by 1 is the same number), thus multypling no numbers at all has to give the identity (much like adding no numbers results in 0, the additive identity). Since the factorial is defined starting at one, 0! multiplies no numbers, thus resulting in 1
