Theory of numbers: Congruences: Euler's theorem
Channel: Richard E Borcherds
Date: 2021-01-31

This lecture is part of an online undergraduate course on the theory of numbers.

We prove Euler's theorem, a generalization of Fermat's theorem to non-prime moduli, by using Lagrange's theorem and group theory. 

As an application of Fermat's theorem we show there are infinitely many primes with last digit 1. 




For the other lectures in the course see https://www.youtube.com/playlist?list=PL8yHsr3EFj52Qf7lc3HHvHRdIysxEcj1H