In the most important stage of high school, it is very important to learn math well. The following is the factorial formula of a compulsory knowledge point of senior two mathematics that I brought to you. I hope it helps you.

Factorial formula of mathematics knowledge points in senior two.

For example, if the required number is 4, the factorial formula is 1? 2? 3? 4, the product is 24, 24 is the factorial of 4. For example, if the required number is 6, the factorial formula is 1? 2? 36, the product is 720, and 720 is the factorial of 6. For example, if the required number is n, the factorial formula is 1? 2? 3n, let the product be x, and x is the factorial of n.

N factorial representation of any natural number greater than 1;

n！ = 1? 2? 3n

or

n！ =n？ (n- 1)！

Double factorial of n:

When n is an odd number, it means the product of all odd numbers not greater than n.

Such as: 7! ! = 1? 3? 5? seven

When n is an even number, it means the product of all even numbers not greater than n (except 0).

Such as: 8! ! =2? 4? 6? eight

Factorial representation of integer n less than 0:

(-n)！ = 1 / (n+ 1)！

The factorials from 0 to 20 are listed below:

0! = 1, notice that the factorial of 0 exists.

1! = 1,

2! =2,

3! =6,

4! =24,

5! = 120,

6! =720,

7! =5,040,

8! =40,320

9! =362,880

10! =3,628,800

1 1! =39,9 16,800

12! =479,00 1,600

13! =6,227,020,800

14! =87, 178,29 1,200

15! = 1,307,674,368,000

16! =20,922,789,888,000

17! =355,687,428,096,000

18! =6,402,373,705,728,000

19! = 12 1,645, 100,408,832,000

20! =2,432,902,008, 176,640,000

In addition, mathematicians define 0! = 1, so 0! = 1!