Help! on 0!

[anthropos]

I was reading my Maths textbook for fun when I came across the chapter on combinations and permutations. The textbook states that the number of permutations of n different objects is

 

n! = n(n-1) (n-2) x...x 3 x 2 x 1

 

Then how should we define 0! so that the above result would stilll hold?? I checked 0! = 1. Hmm... can somebody enlighten me how this works?

[RyanJ]

I was reading my Maths textbook for fun when I came across the chapter on combinations and permutations. The textbook states that the number of permutations of n different objects is

 

n! = n(n-1) (n-2) x...x 3 x 2 x 1

 

Then how should we define 0! so that the above result would stilll hold?? I checked 0! = 1. Hmm... can somebody enlighten me how this works?

 

Maybe this can help

 

Cheers,

 

Ryan Jones