<aside> 💡

I don’t generally recommend watching all of these detailed videos if you’re in hurry and instead study the slides with a pen & paper with an LLM and move on

the quality of this chapter is low since I thought it wasn’t included :)

</aside>

https://www.youtube.com/watch?v=RugWgBLbK9o&list=PLy_2fgXkPiZt3oJcHalAWy9uhQ3wd2fTV&index=7

https://www.youtube.com/watch?v=5AnduNqEV2M&list=PLy_2fgXkPiZt3oJcHalAWy9uhQ3wd2fTV&index=8

https://www.youtube.com/watch?v=21u_6aek4fg&list=PLy_2fgXkPiZt3oJcHalAWy9uhQ3wd2fTV&index=9

https://www.youtube.com/watch?v=baJp5VLjLMk&list=PLy_2fgXkPiZt3oJcHalAWy9uhQ3wd2fTV&index=10

CHAPTER 2: INTRODUCTION TO NUMBER THEORY

2.1 Divisibility and the Division Algorithm

Divisibility

We say b divides a if there is an integer m such that:

$$ a = mb $$

Notation:

$$ b \mid a $$

Meaning: a can be divided by b with no remainder.

Example:

$$ 5 \mid 30 $$

because:

$$ 30 = 6(5) $$

So b is a divisor of a.

Important properties