A Friendly Introduction to Abstract Algebra / Group theory (lesson 1): SYMMETRY GROUPS

You can download problem set 1 here:

00:00 Introduction and overview
02:10 What are symmetries of a triangle?
07:23 D_3 and the composition of symmetries
12:55 Properties of composition in D_3
21:05 D_3 is a noncommutative group
25:36 Please comment
26:42 Do the exercises!

image of Abel from

[hervehascoet]

extremely well done : being very precautions about explaining the concepts so well : thank you . I do think you should have used a bigger paper triangle with some brighter and a bit bigger blobs of colours . Thanks a gain and keep on teaching us please . H.H (Capetown )

[johnmalin]

I think I was already 2 years into my math undergrad and had finished Linear Algebra 1 + 2 before I started to think about what groups have to do with symmetries :) And I feel like I'm still learning something from this video. For me personally, math can also be fun just thinking about the abstract rules directly, but it is really nice to see how it all comes together :)

[rwharrington]

I’ve been hoping to find a good introductory series on Abstract Algebra. Great timing.

[tsnp]

This is fantastic, please keep posting videos!!!

[Rael]

Nice job. I recently had a university course in abstract algebra and your video reinforced concepts that are still rather new to me. I like the problem sets.

[mnqobimsizi]

Every YouTube video must be like this ❤❤

[casaroli]

Thank you.
I will follow the series as a course!

[paulcohen]

I'm a bit confused. Is the set a collection of objects or operations (various spins and rotations) and if so, then why do you need an operation along with the set?

[codework-vber]

Blink & Slow Motion joke made me laugh so hard.

[dieterwagner]

Why are there only 2 ways to rotate? Could you not also rotate in the other direction? (+&-)

[eduardopereira]

There is one basic operation, namely division, which is not associative...

[jamesfortune]

It would be better not to call the identity element id. The letter i has such strong meaning that it could be potentially confusing.