Matrix multiplication (part 1)

[lunarsheep121]

Thank you for the video. Good show.

[Trouter92]

What is with people saying things like "you sir," i think i saw it in family guy. Are you trying to be funny or cute?

[Cesariono]

@Trouter92 It's just a show of respect.

[belshazzar1983]

Thank you SO much for this video. It was easy to understand!

[EJR914]

Mr. Khan, I love your videos. What software do you use create the video where it appears you are writing on a board. I'm very interested in that. Its really cool, I'd love to use it myself.

Thank you for the time you took to answer my question, Mr. Khan. Keep up the great videos!

[Cesariono]

@EJR914 This is just me but I think he just uses a tablet and, well, Paint.

If he's not using Paint then oh well. This can still be done with Paint regardless.

[108everest]

srbija- matrice

[miclo051]

first time i looked up matrix and i got this xD

[Juanguiii13]

you can undo easily by pressing Crtl + Z

[xDieNoob]

We meet again 240p...

[missquprison]

Who sees the number one instead of two in 00:33 ?

[missquprison]

I don't good at English. I really don't know what are you talking about (but you add letters to this video) and i understood Everything ! Thanks a lot !

[MassaSamar]

What vile creature would dislike this?!

[warnerweb]

which program do you use to create your videos? Thanks

[SuperPhg]

I used to bee good at maths but then I took an arrow to the knee

[Matthijsdekroon]

-16 + 6 = 10??

[Do0odiie]

@Matthijsdekroon no it's -10

[SpicyTaco362]

im only in algebra 1 and i am interested in calculus and math like this am i normal ?

[theantiantichrist]

10 factorial?

[frantzzzze]

Thank you soooo much!!!

[DroopyDog17]

matrix cud never run on this crap, just say`n

[soulreaperichig0]

my math teacher is an awsome one but i never paid attention or attended college so u r my teacher :D

[TEEHSOO]

thank you very much , i have an exam tomorrow and you helped me allot with your videos ..

[Nickozz1337]

what would happen if you ..... i cant explain it....... ummm if set up a column vector with 1 and 7 in matrix A and multiplied it by row vector 10 and -8 in matrix B, then continued the process, would you still come up with [-16,130,10,-66]?

[MsKilla76]

u da man

[extrasonic]

This guys is best math teacher I have found! He explains stuff for 10 minutes so nicely, that I can't understand from 10 pages of shitbook texts.

[skullthepower13]

if there wasnt the cookie monster ur my hero

[skullthepower13]

thank you i cant belive anyone could dislike this

you explain this better than 80 lunch dtentions with my math teacher this is seriously facinating and im not even a big fan of math :):):)

[GoombaMushroom]

I love your use of colour!

[claxemomis5]

You sir, are the god of explanation. i got an A on my test because of you .please keep doing what you do

[BLaZeDRas]

amazingly well explained. thanks!

[MrSurfsAlot]

fking lOVE YOU Sal

[TheShiniestStar]

Sir, i was in math high level last year but switched to standard level because it required a lot of practice. my standard level math teacher did not teach me any of the material for the exam and i had to learn them all by myself. i watched your videos for a week and got a 90% in my math exam. :) thank you soooo muuuuucchhhh

[TheLoveformankind]

watching

[ChinoPR001]

Dude thnx alot, my teacher ladie told us to find out how to do this on youtube, I've been hur 4 like half an hour trying to find a good one and yours came, THANKS...

[Juddanator16]

My Teacher sucks! Thank god for you

[i650cutie]

Thank you so much!! My teach didn't really explain this well, and only gave us one example, but you really extended your teaching on the subject!!!

[MickoWongWong]

Thank you so much!

[Maize2Rage]

This 13 minutes makes more sense then 2 weeks of class

[chosengendkl]

-16+6=-10 not 10

[Conspirator19]

I must say, he is one of the very few teachers that inspire me to be a teacher

Thank you so much for your help Sal, you make EVERYTHING make sense that NONE of my math teachers could truly do

[rimzhimshajid]

Thanks for this video! I finally get this!!

[EquinoxParadox91]

I multiplied The Matrix by The Matrix Reloaded. The result was spectacular.

[soccerplaya226]

4:40

me- "FIX IT! GWARHRHAHR!"

[JoshFitzTunes]

Needed this for my MAthematical Economics exam, got really stuck as my lecturer was foreign and I had no idea what he was on about. Thank you so much!!! You're so good at explaining it!

[TheLegendaryFusion]

I get it now. THANK YOU.

[minjee34]

i really have a bad understanding for this those .,, but i really do my best to get it ,, :(

[Leonitusworm]

wait... is this MS paint? lawl

[raheem2327]

thanks now i can get ahead

[iani1051989]

thank you dude...!!!!

[destroyerxx6]

Thanks bruz.

[snottybb]

Thank you sir, and the six people who dislike this obviously dropped out of school.

[lananhdo12]

i was confused beyond understanding the first time i saw this video because the 2 looks like a 1 and the -8 looks like a 9

[FaslifiedHero]

You sir just explained Matrix Multiplication better than 6 hours in my math class along with many hours of studying a book ever did. Thank you sir, glad (Daily Show or Colbert Report) introduced me to you.

[tehmadcap]

"If my maths is correct" I lol'd. It would wanna be, this is my university education

[Stephane4JC]

Who can help me find such a software to write numbers and do maths ?

[TheZzzzzzz999]

Thank for your videos. They are unquestionably extremely aidful to myself, and perhaps the various folks who have seen this video. Your video is indeed going to help me tomorrow marning when i'm taking my final exam. Muchas grasias amigo!!!

[shaneymane15]

linear algebra is a pain in the ass

[therealbirdman10]

how on earth could someone dislike your video. I truly do not understand what could be bad about this

[BeatsDr]

Thank you so much for this channel! In all seriousness you teach these subjects better than my teachers at high school can.

[Thxuxer]

I have completed several math classes, but as always if you don't use it you loose it. I love this channel to keep me familiar with my mathmatic skills. Great Idea!

[MrKamran425]

your two looks likes 1 -.-.

Thanks a lot. rele helped me <3

[Ghaiyst]

damnit! im in ap calculus and this is really confusing and for some reason i dont remember how to do it that well. im nervous for the future. 

[nameless527]

but why do you multiply row and column? why not row and row?

[Zander101084]

you're awesome sal 

[theshocktart]

missed the class where this was taught and I was just struggling with some hw... then I watched this vid and realized how straight forward this was- thanks! I didn't even finish the vid but it all made sense- Thanks much!

[pulsebreathing]

I finally got matrices and it made me so happy.Years ago, I tried and was clueless in a vast horde of students with an arrogant prof. I am so thrilled!! I am going all the way to the end to vindicate myself.

[pulsebreathing]

I finally got matrices and it made me so happy. I gave up years ago and could not advance in math, but now I understand. Thank you.

[nintendo768]

Can you say "Negative" instead of "minus" when talking about integers? it is just like saying "I made a porn"

[catbe123]

-16 + 6 is not 10 ot is -10

[thefarheensauce]

@catbe123 he corrected it in the annotations

[Mr8thsamurai]

i get the strangest feeling that I have thought about this before, even though i have never learned about matrices before. . . .

[eachneverydaynosleep]

wow why can't school be like this

U need time and be able to pause in order to learn

U need to be able to take what ever time u need to learn it and some are slower than others.

[guyx5000]

ur saving my life bro

[dillonjbritt]

you have tutorials for everything dont you

[tanmyman777]

hey thanks a bunch man!

[howtodoapoo]

you'd be such a good hypnotizer

[gtf600]

thumbs if meekakitty brought you here???

[GAWproductions]

I came to this video wondering what the hell matrices were... it turns out that I already know how to do this. I guess America's educational system isn't THAT bad...

[1CelloGirl1]

Thanks heaps for the video, i was away for the whole chapter on matrices so i pretty much just learnt from you! very helpful

[tanel56]

3x6+4x8=51 not 50! noobs!!!!!

[s2000gpw]

@tanel56 no it rly is 50 lol

[Mr8thsamurai]

@tanel56 TROLLY LOLLY

[fbyrupo789]

if only he was my teacher.

[Otacon9944]

This really helped me man, thanks :)

[corvette4554]

thanks man

i like matrix

they are long but easy

[MisterAlexUk]

I wouldn't be able to continue my degree without you.

[vivrey666]

ooooppsy you made a mistake in adding -16 and 6...it's not 10 but -10...

still...you rock!

[pistatic]

whoops I thought there is a agent smith - neo fight

[Amo0dix]

in 4:38 there is a mistake.. -16+6 =-10 not 10 :)

[TheCapslockCritic]

This is great, I'm understanding matrices like never before! A for the quarter, here I come :)

[kashour123]

your an amazing math teacher

[Twinsfan36]

Thanks dude you are so much better than my math teacher!

[Abdullahkm360]

amazing man i didnt understand this in class and im like how am i gonna do this and i thougth about you and im like i have the best teacher MASHA ALLAH online so why not go to him and bam this is a peice of cake

[shikori7]

You are awesome man, I am definitely acing that end of term

[caseystarr]

man you are awesome...im doing an online introduction to linear algebra and its sooo hard and confusing, i just wrote a midterm did really bad then someone suggested you tubing linear algebra, i did i found you and now im in heaven i will no longet have to find a tutour in this tiny little town im living in!!!!! Thank you soooo much technology is amazing!!!!

[enjoyablesounds]

thanks for the videos bro i love you

[FallofDarkness55]

i love the green shading that you use to solve matrices.

[jimmytube717]

3:37 confusing, yeah, just a bit.

[RonBurgundy161]

Holy crap I noticed something. If you multiply the numbers diagonally for both of the matrices at the end, they equal the same number. For example, 23 + 46 = 19 + 50 and 31 + 34 = 43 + 22. Dunno if this has any relevance or not, but hey.

[amaka56]

"I know this is confusing and i feel bad for you right now."

Sal, you are so compassionate, patient, and understanding.

people like you are what make people like me yearn to keep learning and trying.

thank you so much for not only your time, but your educational insights and assistance .

[simsjiujitsu18]

I need help on a problem that looks like

5[-2 -6] 3 1

[Michalbasavraham]

@simsjiujitsu18

That's scalar multiplication.... search it. I think Khan covered it. 

[TheJaykaybay]

Hey umm...... What program are you using for this?

[gamegeta]

good for beginning,thank.

[wwefan2073]

thanks



[xlightable]

Good, this looks pretty simple, now I know how to multiply matrices but have no idea what's the practical use of it or what’s a matrix, lol

[footieholic9]

Sal, you are a beautiful, beautiful man! My high school math teacher couldn't get through to me in more than an hour what you did in less than a quarter! If I can ace my GCE this June, I will love you forever and ever!

[djprinciamerikes]

this makes me leran good im happy and last year i was in 3 now im in 4 and i want to leran bc when when im going to 4 i have to leran more and i dont want to file 4 i want to be smart not stupid

[BLACKRULES1210]

thanks for making this tutorial my teacher made us do this n search it up on utube n ddint teach us how to do this

[qwertyfshag]

shukran akhee

[joannadanna1]

Great video. Just starting with matrices and this was a snap to pick up based on your tutoring. Thanks much!

[Guerilla333]

great video thanks

[virginialikesyou]

DOT PRODUCTTT!!!!!!!!!!!!!!!

[Picuky]

The number of up-right corner should be -2.

Why?--->-8+ (-3x-2)=-2

[Opspin]

@Picuky it's not -8 it's 2*-8=-16 so that calculation is correct, I think you mistake his 2 for a 1

[Picuky]

@Opspin

You are correct!....I thought first number (up-left number of first matrix) were a "1", not a "2". In the video, that number seems like a 1 :S

[ccploneda1]

i love your methods of teaching..you are awesome.i have watched ur vids for about a year now..almost every month lol..thank u

[da5id6301]

The ability to concentrate on your voice aurally and the notation and calculations visually, with colors and, most importantly, to stop and think or rewind and review makes it impossible not to "get." However I get the feeling that there is a missing symmetry. Something must commute. I trust you will reveal it.

[bluewinx15]

Thanks salman that is really help me out ...!!!

[nothingnex]

imba sia if u used paint

[Schturmvogel]

Thank you very much, very very helpful,

Little Q if i may, what program is that?,

(can't believe its good ol' Paint????)

[aduitdfeklfhl]

i cant watch any of your videos....wat to do??

[thenamekatieistaken]

you;re my math teacher.

[TurboX2]

thanks

[natetitus52]

Thank you so much! This video was very helpful.

[ragusajr]

This would be a good way to pick Lotto numbers!

[julezbloom7]

thank you! this helped a lot!

[Ischnitzelyou]

i love the color coordination, very helpful

[Kenji2]

You're awesome! I spent 45mins trying to learn this from my book, gave up, watched this and learned how to solve my problems after watching the first 3mins of this video!

[EvanJuggle]

very nice instructions!

[EvanJuggle]

thank it really helps!

[yujinwu]

I haven't learnt matrix at school yet. this is great prep.

[bearsfan547]

Great video, thank you very much.

[Korzlin]

Beautiful man. I have always wondered what a Matrix was, it was really nice watching the introduction to matrices and this video. I'm going to continue watching the other vids.

[5185988519]

I don't think that you're a beautiful man, but thank you anyway for this video and all others you posted.  You guys are the best (for math)!

[HowAboutSomeTruth1]

What an odd thing to say.

[cervantespr]

why did you call it "the first row vector" were you can call those entries whatever you like? More abstract dont you think?

[MAURICIOBRAZZILL]

thank you, thank you, thank you ! youre great !!

[chriskill08]

i noticed that even though the values in the rows and columns of the matrices change with which matrix you multiply first, the sum of the values in the matrices is still the same....is that a coincidence and does it even really matter?

[eisenhower4312]

i love you thank you so much

im gonna pass tommorrows quiz

[megaelliott]

I have just realised something, when you add the two integers in row 1 colloum 1 and row 2 collumn 2 of BA it is equal to the integers in the same spaces of AB, and also when you add the integers of row 2 collumn 1 and row 1 collumn 2 of BA the answer is equivalent to the sum of integers in the same spaces for AB. This also means that the total sum in all spaces for BA equals AB.

[Jakers2009]

Very good... maths is about noticing patterns like you have done... notice that matricies are not associative but are commutative i.e AB not = BA but A+B = B+A...

[reinhja]

your my hero.

[simplyalif]

Thanks soooooo much. God bless your soul.

[aerolord]

Thank you for this well done video! The way you teaches is way better than my lecturer

[matincool]

This is sweeeeet...thanks a lot man!

[Kavemaster]

you rock thank you

[Ageto68]

you saved me from failing a math final :) amazing....thanks for the !

[kamyarghofrani]

it should be

(2.10 + (-3 . 12))

(there should be a braket

[itsanders]

Um no it doesn't really matter/make a difference.

[kamyarghofrani]

yes, thats the rules

[IsometricCube]

thank you, community service like this is well appreciated.

[hjkfadv]

when you switch the matrix they come out diffent.if you then add up the 4 numbers they come out to the same number. does this happen all the time

19 + 22 + 43 + 50 = 134

23 + 34 + 31 + 46 = 134

if so dose this mean that they some how are the same

[grimshawr]

they will always add up to be the same thing, but in linear algebra the order matters.

[sloppyjoes7]

Can you add a notation that the top right number is NEGATIVE 10?

[g4xtr]

-at 04:38

[khanacademy]

thanks. I added the notation.

[snapple16]

" i know its hard , i feel bad for u right now " hahaha

[pointmade25]

Check this out. if you add matrix A.B, it is equal to the addition of matrix B.A. Check it out.

[airhead2580]

this video is verrry helpful! thank you!

[hodness]

very helpful