Question

Proof that
0! = 1!

No copied answer

Answer 1

n! is defined as the product of all positive integers from 1 to n, then:

1! = 1×1 = 1

2! = 1×2 = 2

3! = 1×2×3 = 6

4! = 1×2×3×4 = 24

n! = 1×2×3×(n-2)×(n-1)*n

and so on.

Logically, n! can also be expressed n*(n-1)! .

Therefore, at n=1, using n! = n*(n-1)!

1! = 1*0!

which simplifies to 1 = 0!