Factorials (Jump to: Lecture | Video )

5!

Above, we have factorial 5. It is the same as writing:

5 * 4 * 3 * 2 * 1 = 120

Here are a few more examples:

3! = 3 * 2 * 1 = 6

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

-2! = No Solution