Question

Why is 0! (Factorial of Zero) is 1 ? Prove it.

Answer 1

n!=n×(n-1)! ...... 1!=1×(1-1)! 1=1×0!...... so 1=0!.....

Answer 2

acc to formula
n!=n×(n-1)!
now put n=0
1!=1×(1-1)!

1=1×0!

⇒1=0!
hence proved