How to find the inverse of a 3 by 3 matrix (3 methods you need to know)

Learn how to find the inverse of a 3 by 3 matrix for your linear algebra class!

0:00 hello!
0:44 [A|I] ~ [I|A^-1)
11:10 A^-1 = 1/det(A)*adjugate(A)
19:35 shorter version of the 2nd way

@blackpenredpen

[aleksgornik]

Gaussian elimination sucks, it’s a bit trial and error and if you take the wrong route you go into a black whole and can’t go out of it

[ProfOmarMath]

It's fun that you're embracing linear algebra

[talentedtobi]

The last method is Gold.

Thanks so much.

[parasgovind]

You have the best timing!!! I literally learned this topic a few days back and always complained about how long it takes! Your third method is awesome! Thank you!

[youkaihenge]

When you drew that big matrix for C that face you made was hilarious knowing we all are suffering from the inverse hahaha

[farkasmaganyos]

I really appreciated the 3rd version! Many thanks for that!

[jordimayorgisbert]

I have no idea about the pretty 3rd method !!! Thank you 🙏!!

I’ll give it to my students next monday !! Very nice !! (Like the D.I. Integrate method 😉)

[MA-bmjz]

Another method would be from the characteristic polynomial, by writting A^(-1) as a linear combination of A and A^2

[geosalatast]

There's a guy with a goat beard who holds a pokeball, has the Picasso painting The Scream and is talking about matrices... Pure Excellence!
Greets from Greece!

[dookey]

I just finished this topic in school, finding the inverse of 3x3 is such a pain for me because I always make stupid arithmetic blunders. Just got to be careful

[jeffayako]

i love the last one u make it look really easy i will try writting a CPP code to compute the inverse using that algorithm

[tomatrix]

Peyam - Funniest math teacher. Bprp - Coolest math teacher.

[TobyBW]

Watching this while doing my linear algebra homework on inverse matrices

[AlfredPros]

That last trick is so cool! I wish my lecturer taught me about it!

[GreAseMonKey]

the last method is the life saver!!! :))

[croz]

I have an Algebra exam next week, really appreciate these videos you are uploading.
Greetings from Chile!

[francine]

thank you so much sir, you made it look easier! I just want to ask a question, regarding the 3rd way 24:30, can I use it still when solving for determinants with 4 x4 or more matrix?

[egillandersson]

The first way is the more "theorically understandable", but the third way is the coolest to perform. Once you have computed the adjugate, you can also ignore the last raw and column and use the centre to compute de determinant (if not previously done). So, an "all in one" method !

[KN-ttxu]

That 3rd method is actually very useful, thank you for showing that

[DarthJeremy]

please note i do not think the last method applies to matrices greater than 3 x 3