Example of Group: GL(2, R) (1 of 3)

EDIT: At 5:30, it should be ad-bc, not det(ad-bc).
Abstract Algebra: Let G = GL(2,R) be the set of real 2x2 invertible matrices. In this first part, we show that G is a group. Using the identity det(AB)=det(A)det(B), we give an indication of how to extend to nxn invertible matrices.

[@AamirHLone]

Thanks sir! Respect.

[@chloemccarthy2297]

"Google, is the GL(n,R) group a group under multiplication?"
"GL is def a group of nxn matrices with real numbers"
"TH-cam, is GL(n,R) group a group under multiplication?"
"Yes indeed it is! Here is a mathmetician to prove it :)"

[@HarryHumpo]

This video is fantastic

[@MathDoctorBob]

Could you say more? It looks correct to me, but I might be missing something.

[@MessiahPsychoanalyst]

Sir,
On the left side, the last line, it seems a typo, det(ad-bc); at 5:32?

[@thenewdimension9832]

❤❤❤❤

[@MathDoctorBob]

Ah! Thanks! Annotated.

[@MessiahPsychoanalyst]

Sir,
(ad-bc) is a scalar. Then det(ad-bc) seems a typo to me. Carefully listening to your lecture, though clears for students what you mean.

[@jhowyvega144]

what book have this problem?

[@MathDoctorBob]

This is pretty standard for advanced linear algebra, or abstract algebra with linear algebra. Artin's Algebra likely has it.

[@the_blackchild]

Why dont u try using numbers cause i can see the direction but it's not quite clear..

[@MathDoctorBob]

Are you asking me to re-shoot a 10 year old video? I usually just find an expert to explain the part I don't get.

[@SPDE1]

Watch this lecture after lecture 10.

[@irfanmirza2748]

is there anyone to answer a quetion

[@MathDoctorBob]

You should just ask it. Best place to go is /r/learnmath on reddit for homework questions.