Proof that the Totient Function is Multiplicative

Coprime numbers mod n: https://youtu.be/SslPWR2N5jA Chinese remainder theorem: https://www.youtube.com/playlist?list=PL22w63XsKjqyg3TEfDGsWoMQgWMUMjYhl Surjection and bijection: https://youtu.be/kt5eABzTVGQ Explanation of why Euler's totient function of a product of coprime numbers is equal to the product of the totients of those relatively prime numbers. Understanding the relationship between those two totients is awesome! Modular Arithmetic playlist: https://www.youtube.com/playlist?list=PLug5ZIRrShJHPX-OyMNLLCQfKXchdZKpE Subscribe to see more new math videos! Music: OcularNebula - The Lopez