The fact that 0! == 1 is a logical extension of the definition of factorial: n! == n * (n - 1)!.

So 0! == 0 * (-1)!, 1 == 0*(-1)!

What is the value of (-1)! that when multiplied by 0 gives 1?

In reply to Re: Re: What is zero divided by zero anyway? by John M. Dlugosz
in thread What is zero divided by zero anyway? by BrowserUk

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