Question

Prove 0 factorial = 1

Answer 1

This may not be a correct proof.

1C1  = 1! / 0 ! x 1!

1 = 1 / 0! x 1

0!  = 1

Answer 2

Proof:
n!=n*(n-1)!
(n-1)!=n!/n
(1-1)!=1!/1
Therefore 0!=1