Bruh algebra 2? I’m a second year physics major in university and we are just learning this now.
@thetheoreticalnerd7662
4 жыл бұрын
I am 12 years old.
@praneetpopuri6512
4 жыл бұрын
I am a freshman learning this
@gavinriley5232
4 жыл бұрын
@Elemental King I went to the lowest performing school in NH and they lost their acreditation the year after I graduated so I didn't exactly get top tier middle and high school education. But now I have work with Karl Slifer at UNH with one of his experiments down at the Jefferson Lab particle accelerator so HS quality really doesn't matter anymore.
@donnyt6792
4 жыл бұрын
I'm a freshman learning this the second week :(
@yiliangliang5694
3 жыл бұрын
@Elemental King depends where you are. In some CA schools they don't even teach matrices in Pre calculus.
@purplehazenilsp
9 жыл бұрын
Thank you! Its absurd how much better you are than my lecturers, I would be screwed without your channel.
@arianasloan6104
8 жыл бұрын
What kind of fucking evil shit is this. Still a great video but this matrices shit is like ahhhhgggh
@kainzed7383
7 жыл бұрын
this is called wizardry and sorcery, a few years ago was forbidden and those committing were burned AAALIVe
@Mahmood367
8 жыл бұрын
LMFAO prevent my brain from degrading
@Sam-lq9ln
5 жыл бұрын
He starts the video: "We will now start the video with what is my least favorite exercise in mathematics." me: turns off he laptop and goes to sleep. Haha, If the teacher doesn't like it, what am I doing.
@CaptainFluffy6644
14 жыл бұрын
"if i keep doing this my whole life it'll stop my brain from degrading" one of the many salman khan win moments
@datorsinc.9162
5 жыл бұрын
I rmb how I gave up on academics in my early years when learning matrix. Now revisiting for nostalgic reason, if I can go back I would have given up again
@manvi4103
8 жыл бұрын
my teacher gave us 4*4 and 5*5 to do -.- RIP me
@Edwin-fw4rh
7 жыл бұрын
what is wrong with your teacher.
@manvi4103
7 жыл бұрын
fr man! idek
@dimakatsomasiteng4183
6 жыл бұрын
LOL
@aminuabdullahi9329
5 жыл бұрын
Lol!
@thesilentvoice3397
5 жыл бұрын
Well it will help ur brain from degrading
@preditor467
10 жыл бұрын
all this crazy ass shit for a 3x3 matrix
@bhaskarrao5254
5 жыл бұрын
Inverting a 4×4 matrice is like living harry potters life
@socksamazingchannel
4 жыл бұрын
I have a final tomorrow and I basically learned the whole semester in 10 hours straight on youtube lol
@nhutran2000
4 жыл бұрын
I AM SO GLAD I AM NOT THE ONLY ONE
@socksamazingchannel
4 жыл бұрын
@@nhutran2000 its possible, but I didn't get the best grade overall lol..
@avi_mukesh
8 жыл бұрын
Wow... I think I'll just stick to inverting 2X2 matrices for now 😂
@khanmc8435
5 жыл бұрын
Wish i could say that to my teacher lmao
@danishmobeen7396
4 жыл бұрын
exactly this was me 3 years ago.....now I am forced to do that......lolz .....well actually I chose it myself (hahahah)
@sashataruberekera235
4 жыл бұрын
Facts.
@danamuise4117
10 жыл бұрын
is 'inverting' a matrix the same as finding the 'inverse' of a matrix?
@Alionn1
6 жыл бұрын
No
@kunyan9551
6 жыл бұрын
what?
@TheFlashness
4 жыл бұрын
I just wanna say thank you so much. I've never done linear algebra in my life before and I'm writing an exam in two weeks... I was stressing so much but with your videos, i'm understanding it all and actually doing it. You explain it so well, you make it so easy to understand. Thank you!!
@zaeny
11 жыл бұрын
What I love about Khan Academy is that, even though Sal gets millions of views on his channel, its not monetised, which could generate tons of income. I HATE waiting for ads to load if I'm trying to watch a KZitem video, esp if I'm revising and trying to get through a ton of material in one day. Thank you so much Sal, you've helped me and millions of others. You should be proud of yourself fella.
@Bouryal.Y
Жыл бұрын
you can use adblocker to avoid the ads
@horikatanifuji5038
Жыл бұрын
@@Bouryal.Y I am not sure if those really worked on KZitem 9 years ago. But yes, I myself too, use an adblocker.
@luiserivaldo3954
8 жыл бұрын
Omg... why did I find you only today? Thank you so much, you just become my Math guider, better than my professor.
@vtgaming9204
9 жыл бұрын
Det(A) = 1 - 0 + -2 He messed up the plusses and minuses with determinate but because the second part of the determinate was 0 anyway it didn't affect it. So those who are getting 3, are doing 1 + 0 - -2, but yeah the plusses and minuses go + - +, not + + -
@firefeathers4058
6 жыл бұрын
VT Gaming Yeah it would be 3
@marambenammar7183
5 жыл бұрын
No he did not mess the signs because he has already multiplied the minor determinants by + - + in the cofactor matrix
@PranabMallick.
3 жыл бұрын
Which Mathematician had come up with this idea?
@hassanouanir6107
11 жыл бұрын
nicely explained sal, it's been a long time for me doing matrices there was a slightly mistake as the result should be -1 1 2 in the first row when you were multiplying by co factors matrix could you provide me with a linear algebra text book "name" that is good since I studied all this in french I would like to look it over again in English I appreciate it, thanks for all your efforts to spread knowledge in all different fields for free to all people
@ScienceMaths2012
10 жыл бұрын
Use the matrix inverse algorithm for matrix larger than 2*2, which is much much simpler to find inverses .
@maestropasser
9 жыл бұрын
why do you only take the values from the first row? for determinate of [A]?
@eye1158
7 жыл бұрын
maestropasser you should read your books also
@gamer4lyfez325
5 жыл бұрын
@@eye1158 you should answer the question and give help instead of being a jerk
@lukewilliams5149
4 жыл бұрын
im wondering the same thing
@shashwatsinghal1241
8 жыл бұрын
one of the best channel ever. thank you sir
@Zarajpat
4 жыл бұрын
This is a very lengthy process.
@Alfonzo6000000
3 жыл бұрын
I really don't know why I bother with my professors when even twelve year old videos from Salman help me understand concepts in less than 20 minutes.
@FleyBlademode
10 жыл бұрын
lol the part he said only take 17 minutes .... Helpful though
@pkking678z
3 жыл бұрын
We had to invert a 5x5 matrix of an economic model, and do all the related operation with a 5x5 matrix for an assignment. We were given 6 days to complete. Seemed a bit unfair
@musthafaaltaf505
4 жыл бұрын
watching this in 2020 be like wth
@suzanmohanna9838
4 жыл бұрын
Right😂
@salah1x
2 жыл бұрын
My professor is giving me equations where inverting a 4x4 matrix is only a part of it 😢
@cc_snipergirl
Жыл бұрын
Feels weird that I was just learning how to use letters in place of numbers when this video was published and now I'm here studying for college level calculus. But also your videos have been just as essential to me as the videos provided with my ebook.
@racingturtle3590
4 жыл бұрын
Thanks again Sal you are the best it cn get confusing ikr 😅 buh will mke tt smehw
@angelaantonmapeso8144
10 жыл бұрын
Is the checkered board always applicable to start at a positive sign or to start it off with the sign opposite to the 1st number in the first row?
@stevenvanhulle7242
8 жыл бұрын
Maker of these videos should stop trying to write with a brick (mouse) and start using a graphical tablet instead.
@gabrieltnc1
9 жыл бұрын
I think just combining it with the 3x3 identity matrix & using gauss jordan is easier to get the inverse. Just like a 2x2, only bigger.
@davidthaler7018
5 жыл бұрын
gabrieltnc1 Gets you the same answer in less time.
@vakaman1
15 жыл бұрын
Hey Sal, thanks for the great video! :) But how do you apply this for a 4 by 4 or n by n matrix?
@djprometheus923
4 жыл бұрын
he says he's building up an appetite doing this problem lmao
@RJCMCMLXXIX
11 жыл бұрын
OMG you're a legend Sal, I just did a 3X3 plopped it into a calc, and that sweet feeling when every entry was right.
@akhmadjonovakromjon3669
6 жыл бұрын
Anyone from 2018? I LOVE MATH :-D
@rossmcdonald5600
6 жыл бұрын
2018 represent
@idontexist1184
4 жыл бұрын
I love math, just not this kind of math.
@catalyzt7162
3 жыл бұрын
@@rossmcdonald5600 2021
@furyzlm7853
Жыл бұрын
just realised this vid is 14 years old, WOW
@PicturePencil
4 жыл бұрын
I feel validated even Salman Khan hates this
@SuperShadow
9 жыл бұрын
Part 2 is an alternate way using RREF and junk. Much easier. My course didn't even touch on the methods mentioned in this video.
@randhawaa386
4 жыл бұрын
I think the determinant of 3*3 matrix is -3. I calculated it in both ways you explained in video and the answer came out to be -3.
@kyranpillay7702
9 жыл бұрын
Shouldn't the det(a) =-3 ???
@vermichou
15 жыл бұрын
Really great, well explained, simple !! I've never learnt that before and following the steps with you gets my head around matrices !!! Cheers!
@LeBadman
13 жыл бұрын
I can't believe they teach this stuff in highschool. Uni math is more like.. graph theory, base 5 numbers.. etc.
@FourOneNineOneFourOne
13 жыл бұрын
I'm amazed you didn't make a mistake =D. Got the identity matrix when multiplied those two together ^^
@ryanjackson0x
3 жыл бұрын
How do you know the steps for this? Very interested to learn the proof and history behind this.
@david0aloha
15 жыл бұрын
I didn't do any matrices in high school (though I did my gr. 11 and gr. 12 pure math classes in the same year while they were changing the curriculum around) and you're saying that they do this in many curriculae in the US? I'm doing this now in university, and I'm able to wrap my around it fairly well, but man is it tedious (and I'd imagine hard to understand if you didn't see the purpose or are unable to visualize what it represents).
@smokethatbong
15 жыл бұрын
Ok I have tried this method with 2 different matrices now and it has worked for neither. It only seems to work for yours because you are using such a simple staarting matrix. I like your videos but the examples you use are far too simple. The same with the gausian method, it is much much harder with a larger numbered matrix. Please show me how this method works for the following matrix. 2 1 -1 5 -2 1 -1 -4 3
@mrseddy14
13 жыл бұрын
If you have a graphing claculator there is a really easy way to do this........ Skip all steps...... Put your matrix in as a 3x3 and fill the number in. Then get this on your calculator screan [A] and use the x^1 button on the left of the calculator so it says................. [A]^-1.............. push enter. Answer... Easy as pie :)
@fatoubomjatta5537
6 жыл бұрын
You are such a amazing teacher.. hope one day I will meet you in person.... during lectures in class I though I will never understand but u made it so easy to comprehend.... thanks you so much sir..... maths genius
@Rejpi
15 жыл бұрын
smokethebong: Try one more time using exactly the same method, I have done your example using khan's presented method and the result is all good. (I have checked it using calculator). You had to made some errors while computing negative numbers. There are some fractions if that cheers you up :)
@ThingsThatMakeMe
11 жыл бұрын
omg thank you so much, this made learning how to swap frames from a 3x3 inverse matrix into a different frame
@tedoymisojos
13 жыл бұрын
Thank you so much! I have such a hard time studying
@ElderBerriesHamster
12 жыл бұрын
wait wait wait wai!!!!! i think you were supposed to take the transposed matrix of A before doing the Matrix of Minors? or am i waaaaaaay off? or did you take the matrix of minors using colunms the rows opposed to rows then colunms? fu@ck!!!
@fizaanTech
14 жыл бұрын
@stothek2 Swearing is for uneducated people with no other choice of words because their vocabulary is so small. If you're watching these videos, you're educating yourself. I can swear if I want to, I just choose not to, especially in this kind of setting.
@will3330
15 жыл бұрын
There is a different way of doing it by using Gaussian Elimination with the nxn matrix and the identity matrix and trying to manipulate it so that it ends up the identity matrix and then the (nxn)^-1 matrix
@the988
15 жыл бұрын
Good job ! U got it right of course, I multyplied it out and as expected it gives me the Identity matrix .nOW i UNDERSTAND WHY U DISLIKE THEM..I JUST HOPE ITS NOT GOING TO BE ON MY MIDTERM !THANX A LOT, UR GREAT !
@LiyaN122
13 жыл бұрын
Its easy because he always chooses easy numbers. Its easy to solve inverse matrix with 0 and 1.
@onmyblindside
15 жыл бұрын
I used this video to answer a quiz question and I arrived at the correct answer! thank you for posting this informative video.
@fpen3
Жыл бұрын
If you augment the Identity matrix of whatever of A is and then get the RREF of A while also performing the same row operations on the identity matrix. The identity matrix will be there inverse of A after you get A to be RREF.
@annaholm9704
2 жыл бұрын
Seems like you're just applying random algorithms just for giggles. I can memorize the method, but I have no inclination as to the purpose.
@DelphianSociety
12 жыл бұрын
So basically, if I got the terminology right, to get the adjugate of matrix A, you need to get the transpose matrix of the matrix of cofactors? lol
@lordswit6666
14 жыл бұрын
this is what my Engineer tutor told me... unlike my teacher in ateneo.. she does the row x bla bla bla which is so confusing.. thanks anyway
@jandresfg
12 жыл бұрын
Isn't it better to use the Gauss-Jordan method? having [A | I] in order to get [I | C], where C is the inverse of A. Pretty much shorter
@Ethonf90
12 жыл бұрын
One hundrdt times easier if you use the Gaußian algorithm. Then its no problem to find the inverse of 5x5 matrices or even bigger ones.
@yazmeen1998
4 жыл бұрын
didnt really like how he described taking the transpose of a matrix. really your just swapping rows for columns and columns for rows.
@cc_snipergirl
Жыл бұрын
This stuff is hard, but imo this is much easier and faster than the Gauss-Jordan version we were taught, especially since this is the way we were shown for 2x2
@LeBadman
13 жыл бұрын
Why do you use a mouse and a computer instead of plain simple paper and a pen?..
@zkuzio
15 жыл бұрын
ur a fucking legend......i spent a whole yr trying 2 figure this out....got my exam in 2 days n u finally helped me.....cheers mate.
@nivvig
14 жыл бұрын
quick question... why did you calculate the matrix of minors? why didnt you straight away calculate the det|A| and then the adj
@maymiller3639
5 жыл бұрын
What the hell bruh I be rewinding😂
@RsGhost1
12 жыл бұрын
Isn't it much easier to transform matrix A to I, and then repeat the steps you performed on matrix I to get A inverse?
@jamesusespivot
12 жыл бұрын
Khan, wake up. The matrix has... 3 rows and 3 columns, can you invert it?
@tz_reaper6628
11 ай бұрын
Our teacher barely teaches this and im a sophomore in highschool, thank you for this explanation!!
@JaLalalover
13 жыл бұрын
Uhm, how do you use this in real life? -_- I so don't want to learn this but oh well! Dear school, I love u!!!
@DarkoSupe
12 жыл бұрын
universally speaking if you have 4x4 matrix r11 r12 r13 r14 r21 r22 r23 r24 r31 r32 r33 r34 r41 r42 r43 r44 to get equivalent + or - you just use indexes of matrix elements like this: (-1)^(i+j) for every element. for example, if you use r32: (-1)^(3+2) = (-1)^5 = -1 so you put "-" to corresponding place
@haydenphillips5956
4 ай бұрын
gods truth thank god for this video this is such a long stupidly complex process
@donosothegreat
11 жыл бұрын
For matrix of minors, the element for row 1 column 3 is incorrect, right? it should be -1 instead of -2.
@djp117
12 жыл бұрын
WRONG TERMINOLOGY! The adjoint or adjugate is the complex conjugate of each element then transpose!!!!
@8dimensions854
15 жыл бұрын
"It will prevent my brain from degrating" That was funny :D Thanks again for your hard work, you're the modern kind of a superhero.
@catalyzt7162
3 жыл бұрын
wow i can't believe this comment was made 11 years ago. I feel like i'm in a time warp
@kv310
12 жыл бұрын
@dqds Then go and seek the proof so you feel better, you can find it in any linear algebra book.
@thatiswhy1
12 жыл бұрын
i am user of your site but i cant ask question der ? y? and from where can i ask ma questions?
@jimmyrussels3746
5 жыл бұрын
my man really out here saving lives
@joevaghn457
Жыл бұрын
Inverting 4x4 matrices is probably insane 😭😭
@hedonism13
14 жыл бұрын
Thou hath conquered the mighty 3x3 matrix inversion. Huzzah!
@knotnyce
12 жыл бұрын
only thing more unpleasant than inverting a 3x3 matrix is inverting a 4x4 matrix.. haha
@BrianHardoin
14 жыл бұрын
if i fucking hate matrices, but found this helpful, should i like or dislike this video?
@Rabixter
11 жыл бұрын
Matrix of minors..... matrix of minors.... matrix of minors..... matrix of minors.....
@frother
14 жыл бұрын
How do you get 4 degrees from MIT and not understand Undo?
@naturenuerologist8396
4 жыл бұрын
What is the difference between transpose of a matrix and adjoint of the matrix??
@priyandumbajpayee4398
3 жыл бұрын
Sir, why they did not use the same minor and cofactor rule for 2×2 matrix.
@mirelvtl8830
Жыл бұрын
so i can just get rid of that Gauß Algorithm for Inverse? great
@aeromatt
14 жыл бұрын
its a special case cause the matrix is symmetric he explains that in the video.
@fizaanTech
14 жыл бұрын
@bbhardoin like, and please don't use bad language. kids watch these videos.
@greysonboedeker507
Жыл бұрын
My teacher ( I’m a sophomore in high school) doesn’t teach this well at all
@badrmoubile6900
8 жыл бұрын
Why don't use The rule of Sarrus, it's much easier, not?
@Samidajani2
11 жыл бұрын
row reduction using I matrix is much easier and quicker than this method
@gsparkway324
10 жыл бұрын
Do this is all a matter of not making any careless mistakes. One teacher called this "a matter of bookkeeping".
@bla7091
14 жыл бұрын
My professor told me to do this by row operations to turn the original matrix into an Identity Matrix, repeating the same steps in an equally large Identity Matrix that would then turn into the inverse matrix. Way way harder than using determinants
@rokinumi
11 жыл бұрын
the only video which is not so much impressive of khanacademy. :/
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