Introduction:

The factorial of a number is a mathematical function denoted by an exclamation mark (!) following a number. It represents the product of all positive integers up to that number.



Understanding Factorial:



The factorial of a number n (written as n!) is the product of all positive integers from 1 to n.

It is only defined for non-negative integers.

Formula for Calculating Factorial:



The factorial of a number n is calculated using the formula: n! = n × (n-1) × (n-2) × ... × 1.

The factorial of 0 is defined as 1 (0! = 1).

Example of Factorial:



The factorial of 5 (5!) is calculated as:

5! = 5 × 4 × 3 × 2 × 1 = 120.

Key Points to Remember:



Factorials grow very rapidly with larger values of n.

Factorials are used in permutations, combinations, and other calculations in probability and statistics.