What is factorial?

Question

only difenition of it I have to know

Answer 1

The factorial of n (n!) is defined as follows: n! = n * (n-1) * (n-2) * ... * 1

for example:

4! = 4 * 3 * 2 * 1 = 24
5! = 5 * 4 * 3 * 2 * 1 = 120

also:

0! = 1

Answer 2

Sachindlabua is coreect. In addition I should say, negative numbers dont have a factorial. And the factorial of 0 os 1.