Inverse of a 2x2 matrix | Matrices | Precalculus | Khan Academy

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Example of calculating the inverse of a 2x2 matrix
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[@danielchickering4579]

He explains it better in two minutes than math teachers do in an hour

[@talonkellen3043]

instablaster...

[@jeremiahekott5658]

The pain man, in just two minutes I understand what for a whole week i could not understand 😞

[@PenandPaperScience]

Online education to the rescue!

[@Osamoele]

Nope, very nearsighted and quite wrong statement in many cases. I had many teachers quite as good as him, and yet I understood better on internet. What changes relative to classes here is mostly context and unrelated to the teached itself, let me explain : it's just that in class you have a whole day of concentration on other topics behind you, which may not be the case here, there may be perturbations, which is not the case here, the teacher cannot re-record if he notice he wasn't didactic enough or went unclear because of some student asking question that are too much ahead relative to the rest of the class, you cannot play backward a part to view it several time to understand it better, you cannot skip if you aready know aqnd it is boring, and finally you are not here by choice, which is the case for this video.

[@PenandPaperScience]

@@Osamoele That's well said; I guess you also need to have some luck with what teacher you get in front of you. Anyway, I think both complement each other perfectly!

[@Dafefoe44]

Lord Bless you!!!! My teacher made this so much more complicated than it needed to be. WOOT!!

[@ultraiq]

Dafefoe44 true.. I’m 8th grader in algebra 2, and my teacher is so bad.

[@111_ALI]

Same here bro

[@SmIle-eq3be]

OMG fr I feel so smart now. Why do teachers gotta make things way more complicated than they actually are

[@nagavamsiy1461]

This doesn't work all the time, to example 2,1 in 1st row and 1,1 in 2nd row comes out to be some answer but the real ans is 0,-1 in 1st row and -1,2 in the 2nd row. If I am wrong , help me out with this!! Can anyone help me

[@kf5058]

Mine too

[@firebird1993]

It may be useful to mention here that the determinate must NOT be equal to 0 in order for a 2x2 matrix to be invertible. This is because in the formula used to find the inverse of a 2x2 matrix, you must compute 1/determinate, and a denominator cannot be equal to 0, therefore the inverse cannot be found. So in short, if the determinate = 0, the matrix does not have an inverse.

[@linusbao8650]

thx

[@chaoticinflation5766]

god bless ur soul

[@jvdv4940]

what if the determinant is 1 ??? We'll get 1/1...

[@andriestebogomarebane9753]

@@jvdv4940 yes we will get 1/1

[@ubaidshah1910]

Jean-Vincent DEVIGNE thats fine

[@angel.6110]

You're enthusiastic voice is me in any social situation.

[@airi8674]

I have a test on matrices tomorrow so I'm binge watching all the videos about matrices on your channel lol- these explanations are really straight forward and even though I sit in class for 45 mins hearing a teacher explain this, I don't understand anything. but watching this video makes everything so much clearer

[@bags7220]

never study nite b4

[@SniperzInvictus]

Amen

[@olay4520]

@@bags7220 nah thats what we do around here

[@puddleduck1405]

same broooo. mine is on vectors, matrices and further calculus. Im so screwed lol

[@hunter_bs463]

Same haha

[@justincren8259]

I came here after trying to learn from online school and learned the info much better. Thank you, thank you thank you!

[@mikeduck5412]

But my in school they teach us that when u switch the first diagonals and take the negative of the second diagonal that’s the inverse of “A” instead of adj of “A” ... am confused 🤔

[@alanperez4629]

Thanks a ton Sal! This is a much easier process than my professor makes it to get this result! Hopefully she won't disqualify this procedure when I use it on my exam tomorrow!

[@SniperzInvictus]

This guy deserves a raise. He has saved me numerous times

[@AlbertoGonzalez-qz9kw]

Thank you. My online class made this much more confusing that it had to be. You made my day.

[@alanwalter9382]

I know it's been years but still thank you a lot for sharing this. I am in ninth and doing self study for the upcoming board exams and your videos are helping me a lot. Hope I get good Marks.

[@user-ol7sl3qw2l]

9th and board exams upcoming which country dude?

[@mishkatfarah5632]

How was your exam bruhh

[@disasterXstrikes]

THANK YOU SO MUCH!!!! ~Sincerely, a Linear Algebra student.

[@kyng_authentic550]

Nice thank u so much §

[@crazytoker15]

you LITERALLY explained it better in 2 min than my teacher in 4 sessions -_-

[@sh4pp31]

I spent 30 minutes trying to understand from the book and this guy taught me in 2 minutes bruh

[@michaeltheisen]

As always, thank you for explaining something so succinctly.

[@downtownline7839]

Appreciated! Much more faster and easier solution than my books

[@TheWinnieston]

Thanks so much! But why oh why would I need the inverse of a matrix and why is it so hard to get?

[@jellevanderdrift1302]

Watch 3blue1browns video about it

[@cobywhitw5748]

"shame this is an algebra 2 class and you can only learn the mechanics of it" bruh im in Controls and i need this

[@starqian6334]

But what's the point of this i don't get why we need to learn it

[@SkylarkTorch]

You sound so enthusiastic about this process.

[@Rockyprincesses1]

MY TEACHER TAKES AN HOUR AND A HALF TO EXPLAIN THIS AND YOU DID THIS IN 2 MINUTES? OMG THANK YOU

[@jamesriri1810]

Very useful and straight to the point.

[@headyshotta5777]

Made this so simple to understand. thank you!!!!!!

[@atulyadav1387]

Thanks my teacher made it so complicate involve many steps you made it easy.

[@syedsadiqhussainshah3602]

Thank you, thank you, thank you, thank you, thank you, this is why whenever I am stuck I open Khan acedmy... Thank you again you made it so easy for me.

[@based_dragon_0110]

1:59 In other words, switch the numbers switch the signs

[@skyysechec4431]

' and we are done ' :') . I loved it thanks.

[@DharejaAcademy]

Good approach and colorful way guided well. But I think you must mention general formula how to get adjoint of 2-by-2 matrix for viewers. How ever good job.

[@ekeneumeh]

short and simple, thank you

[@tylerdavis2920]

My teacher did another method and I think this is easier to find the inverse

[@JamesBrodski]

Great video! Thank you so much for making it.

[@hamnahassan5530]

Thank you from the core of my heart GOD BLESS U 💜

[@ajibolaekunola]

This is a very good explanation

[@sefakolichaba7905]

The explanation its more than the way lectures can do

[@nathandobbs7540]

I know this video's old, but thank you!

[@takiahmed5575]

I have exam in 50 mins. Last minute saver 😊

[@mathbosses6493]

The way the video was introduced 🤣🤣 thank you though, useful content

[@annakapiye2788]

U are the best teacher ever

[@xornedge8204]

Helped a lot. Thanks. I just went to check the website and i don't know how to make fractions. Is there a function?

[@xdgaming952]

great revision, thanks

[@Noon-ln5jk]

Thank you sir! You made this easy

[@mrkahlon2264]

Thanks sir but me problems sign de so kida solve ho sake va

[@abodi9972]

our proffesor today skipppppp thhaaaat !!!! Thank u boss

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I JUST LOVE YOU. THANK YOUUUU SOOOOO MUCH

[@JimmyVuTran]

These updates are always awesome

[@mariamg.w8938]

this is actually simple my teacher makes it complicated

[@111_ALI]

Thank-you so much man love from India

[@serabelesekonyela7604]

Best teacher ever

[@cookiee669]

I understood it so well. I love youuu

[@AnimeFan-dl4qd]

Is there a video where he explains what a matrix, determinante is?

[@jessicafriedman6763]

i am not kidding you, my math teacher put a problem up on the board as we walked inti class and told us to solve it (we had just finished the last chapter/took a test the day before so this was all new). gave us a minute to 'figure it out', asked one student for the answer, and said all right next part. DIDNT EXPLAIN IT AT ALL.

[@nadiasj2501]

excellent explanation .

[@ID_Station]

Thank you, I am taking Linear Algebra and I feel like my teach does instead of explains.

[@saeedsalem728]

Quick and nice 👍🏾

[@silenceisbrilliant]

Broo so awesome thank you so much 🙏

[@vincentmira5942]

what if the 2ndary diagonal has both negative signs?

[@user-ip2cz7vj7x]

Straight forward tutorial

[@sohaibafzal7569]

Nice really helped a lot

[@muhibali205]

I think there is a last step which u left. I mean in books, in end of ques. It is written A-1=I. what does that mean??

[@adrianvillafuerte2623]

so always multiple the second diagonal by -1?

[@nghitran7615]

This video is so helpful

[@nadboyz8564]

A millions thanks for this

[@reema.9117]

THANK YOU THANK YOUUUUUUUUUU 🧡🧡🧡☹️☹️☹️ GOD BLESS YOU

[@khalingyabesh]

15 noowember tak vedieo delet chaiyeee. Anyways thank you brother.

[@lifewithdylan]

amen

[@biswajitdutta4456]

thank you so much for this

[@ludvigsoderberg129]

Great help

[@tahmidadib4018]

Khan Academy u guys r amazing but there is a problem...U guys have to increase your voice level so that we can hear it without headphones...One who agrees can press the like button or send reply in order that Khan academy sees that it is not only my problem...Thanks

[@someguy1688]

Tahmid Adib wear headphones

[@headyshotta5777]

ok khan academy with the 720p. i see you!!

[@rohanharikr]

What about 3X3 matrix and above?

[@MurunGD]

Thanks dude!

[@Lama-jx2ej]

If the def(a) gave us a zero then the s; does not exist right?

[@rahulmad2359]

What is the difference between a singular and a non-singular matrix

[@ultragamer4465]

How can I inverse a (a b) matrix?

[@Cookingwithkawish]

Nice

[@applepeel1662]

Does this work with fractions too? Cause it doesn't seem so

[@ax8621]

why someone disliking this? this video is useful😭

[@arif4003]

so helpful

[@Coolnushi]

This was good

[@amanuelkahsu9103]

2:45 cool

[@edwinosei2764]

I love u guys God bless you

[@drag0nheart786]

how would i go about solving this : A = 2 -1 find the 2x2 matrix B such that AB= 4 1 0 3 0 -3

[@imtonk1]

B= 2 -1 0 -1

[@fluffy_creature2613]

I have no idea what this is

[@user-jg9jw6pz3d]

thank you

[@sillystranger3721]

thnx man!

[@leonscott6929]

I thought it would've been harder

[@hemalathae923]

Awesome vid

[@pako2029]

Thank you 🙏

[@nagavamsiy1461]

This doesn't work all the time, to example 2,1 in 1st row and 1,1 in 2nd row comes out to be some answer but the real ans is 0,-1 in 1st row and -1,2 in the 2nd row. If I am wrong , help me out with this!!

[@phoebed13]

Thankss

[@rubyrubyneyruby]

يسعد دينك يزلمه

[@liamlaran8691]

THANK YOUUUUUU🎉❤

[@danielgeorge2661]

You are awesome

[@KAZTRO_JOD]

Thank you❤️

[@irshadali6626]

very good this vedeo sir

[@Yoyoboy7]

ur a legenddd

[@nn9253]

How can I suit (prove =i)

[@Mohamedhassan-ep5ek]

Waaaaaw thank you so much sir

[@baldeagle6113]

Why do teachers make it hard like legit it’s as simple as that and they make it seem like you need an Iq of about 200 to do it

[@languageartsgrade]

Thanks, Sal!

[@efath-bz8hv]

Life saver

[@attractiveallroundergirl6127]

❤ thank you