Introduction to number theory lecture 23. Primitive roots.

[@richerzd]

I really like the teaching style here of motivating the proofs by analyzing small values and finding patterns! This makes the proof feel less magical like they appear out of thin air, and more natural like they can actually be found by a human.

[@benjamindavid7371]

Another proof of the result at 22:36 is to note that we can write the residue classes mod n as the product ab uniquely, where b is coprime to n. Hence for a fixed a there are exactly phi(n / a) choices of b, so \sigma_{a | n} phi(n / a) = \sigma_{a | n} phi(a) = n.

[@sachalucienmoserferreira2233]

Thanks for sharing your knowledgment with us. Hugs from Brazil!

[@robertgonzalez8859]

good lord, why are textbooks and other videos so opaque about this material? thank you for uploading this!

[@lempuujjj2877]

I THANK GOD FOR THE EXISTENCE OF PROFF RICHARD E BORCHERDS

[@mathismind]

Thanks!

[@migarsormrapophis2755]

yeeeeeeeeeeeeeeeeeeee

[@ethanjahan780]

You again, mysterious yeee man

[@migarsormrapophis2755]

@@ethanjahan780 yeeeee