0!

Hey /sci/ I usually don't lurk here but I have a question for you guys.


I don't understand how 0! = 1
I need to write a proof using "n" as a variable and without using zero in the actual proof but I'm completely stumped.

Can someone please explain this to me??

The answer lies in the principle of n!=n*(n-1)!.

Because of the identity 1!=1 combined with the above identity,

you get

1!=1*(1-1)!
1/1=(1-1)!
1=(0)!    <--- This being the resulting identity.

Hope this helps.