What are Factorials?

This video tutorial explores the concept of factorials, a mathematical operation used in various fields such as combinatorics, probability, and calculus. It explains the notation and definition of factorials, provides examples to demonstrate how to calculate them, and discusses their recursive nature. The video also introduces the factorial formula and offers practice questions to reinforce understanding.

What is the factorial of 5?

• 25

• 120

• 15

• 5

How can 5 factorial be expressed using 4 factorial?

• 5 * 4!

• 5 / 4!

• 5 + 4!

• 5 - 4!

What is the factorial of 3?

• 12

• 9

• 6

• 3

If n = 6, how is 6 factorial calculated?

• 6 * 5 * 4

• 6 * 5 * 4 * 3 * 2 * 1

• 6 + 5 + 4 + 3 + 2 + 1

• 6 - 5 - 4 - 3 - 2 - 1

What is the value of 4 factorial?

• 12

• 16

• 24

• 20