Matrix multiplication (part 1)

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  • เผยแพร่เมื่อ 5 ก.พ. 2025
  • Multiplying two 2x2 matrices.
    Practice this yourself on Khan Academy right now: www.khanacadem...

ความคิดเห็น • 443

  • @VoidBiscuit
    @VoidBiscuit 8 ปีที่แล้ว +578

    I was so sad, then you were like "I know this is confusing and I feel bad for you". Thank you so much :)

    • @brokenking5044
      @brokenking5044 6 ปีที่แล้ว +8

      Im just screaming "BUT WHY???" every 30 seconds. Feels gud

    • @fredhair
      @fredhair 6 ปีที่แล้ว +8

      @@brokenking5044 If you ever need to do anything to do with 3D graphics you'll be so glad matrices exist!

  • @Thehero394
    @Thehero394 9 ปีที่แล้ว +147

    BEST TEACHER IN THE WORLD!

    • @ledabasile112
      @ledabasile112 9 ปีที่แล้ว

      Thehero394 I agree completely!!!

    • @zuesr3277
      @zuesr3277 9 ปีที่แล้ว

      I agree.

    • @jimkeller3868
      @jimkeller3868 8 ปีที่แล้ว +1

      Yes and no. I prefer providing context first rather than later. Like...what is this used for?
      As an analogy, doing it the way he does, is building a building that you have no idea what it will look like when it is done. You are simply following instructions towards the final product. Conversely, I like knowing up front what a building will look like when it's done. Why am I placing this block here? What is it's purpose? He is just manipulating numbers without any purposeful context. But yes..he does that well.

    • @justlikedirt9634
      @justlikedirt9634 8 ปีที่แล้ว +8

      He's the teacher of the world

    • @cocoa020
      @cocoa020 8 ปีที่แล้ว +7

      most maths taught in maths class are taught theoretically. Application comes in your science classes. He is a good math teacher.

  • @azzabethleigh8638
    @azzabethleigh8638 8 ปีที่แล้ว +180

    I laugh because this guy has been helping me get through my math classes as long as I can remember lol

    • @rawaaalnatour1744
      @rawaaalnatour1744 5 ปีที่แล้ว

      onboard with bvlgari before you leave you today XD

  • @Gdicchkclctslyydassysltleaeyls
    @Gdicchkclctslyydassysltleaeyls 12 ปีที่แล้ว +37

    Khan Academy has taught me more in 30 minutes than an entire quarter of college ever has! Well done!

    • @dendi1076
      @dendi1076 ปีที่แล้ว +1

      yup those senile profs only interested in taking college fees and doing research should be fired

    • @lemondrop8203
      @lemondrop8203 ปีที่แล้ว

      More like you can't listen in colledge

    • @Gdicchkclctslyydassysltleaeyls
      @Gdicchkclctslyydassysltleaeyls ปีที่แล้ว

      ​@@lemondrop8203Oh shut up🙃

    • @yhavry
      @yhavry ปีที่แล้ว +1

      @@lemondrop8203 that why you're here?

    • @lemondrop8203
      @lemondrop8203 ปีที่แล้ว

      @@yhavry Erm.. maybe

  • @DrayzerBeats
    @DrayzerBeats 7 ปีที่แล้ว +49

    I watched at 1.25 speed 2 hours before my maths test. Thank you for existing.

  • @graphitehooman
    @graphitehooman 8 ปีที่แล้ว +294

    in the product table it will be (-10)

    • @jonesy5121
      @jonesy5121 6 ปีที่แล้ว +9

      THAT'S WHAT I THOUGHT but I really hope he just made a typo!!

    • @shawnybless
      @shawnybless 5 ปีที่แล้ว +6

      @@jonesy5121 nope his answer was legit he made the same mistake in the addition video as well

    • @jonesy5121
      @jonesy5121 5 ปีที่แล้ว

      @@shawnybless rip my life I have a methods sac today ughh

    • @ailtommoto1226
      @ailtommoto1226 5 ปีที่แล้ว +1

      Jonesy Lol I have one tomorrow on chapter 7

    • @treyannajarrett8024
      @treyannajarrett8024 4 ปีที่แล้ว

      Ikr😂

  • @myadouglas4083
    @myadouglas4083 8 ปีที่แล้ว +17

    the part when he said i feel bad for you i lauged but i enjoy it and now i finally getting to understand it thanks to you khan academy.

  • @Raggy1998
    @Raggy1998 11 ปีที่แล้ว +16

    YOU ARE THE BEST TEACHER EVER!!!!!!!!

  • @faizalimuhammadzoda4731
    @faizalimuhammadzoda4731 7 ปีที่แล้ว +4

    I guess you realize how many lives you are saving every single day (or every time the video is watched and understood). Thank you so much. Jazakallahu khayran.

  • @Lasaro7499
    @Lasaro7499 9 ปีที่แล้ว +12

    Thanks for the crystal clear explanation. I failed this class twice but I think with these vids I'll pass. I just see a tiny mistake on arithmetic. On 4:39 it should be negative 10.

  • @mazen843
    @mazen843 10 ปีที่แล้ว +100

    i lost it when he said i feel bad for u hahaha

  • @Oto2k11
    @Oto2k11 7 ปีที่แล้ว +3

    let me tell you i missed a class in my mathematical economics class on this and you explained it so well. you guys have really helped me during my university career from level 100 to my final year in 400 level and am in nigeria you dont know how much you guys have done for me thank you thank you

  • @HermesvV
    @HermesvV 12 ปีที่แล้ว +5

    I haven't watched your videos in a while and I think I almost forgot just how spectacular of a teacher you are compared to others.

  • @Damian-sh8hu
    @Damian-sh8hu 7 ปีที่แล้ว +14

    I love this channel, going to school is useless while you can watch these videos at home...

    • @sizhuqu5425
      @sizhuqu5425 6 ปีที่แล้ว

      at least we earned some credits ...orz

  • @Divine-Love
    @Divine-Love 9 ปีที่แล้ว +153

    LOL It was hilarious when he said "I feel bad for you".

    • @siddhant3852
      @siddhant3852 7 ปีที่แล้ว +2

      when he said so?

    • @klairehoang667
      @klairehoang667 5 ปีที่แล้ว +1

      siddhant pandey 3:39

    • @adi_yerabati
      @adi_yerabati 6 หลายเดือนก่อน +1

      Now I understand what he meant 16 years later 😭

  • @theshocktart
    @theshocktart 14 ปีที่แล้ว +1

    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!

  • @Aljedubru
    @Aljedubru 10 ปีที่แล้ว

    after watching a few of your videos, I can safely say I'm not sick-to-my-stomach nervous for my algebra exam in 5 hours. you life saving man you...

  • @Conspirator19
    @Conspirator19 13 ปีที่แล้ว +2

    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

  • @JoshFitzTunes
    @JoshFitzTunes 13 ปีที่แล้ว +1

    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!

  • @rollock
    @rollock 12 ปีที่แล้ว

    The fact you use paint, and what looks like a graphics tablet, means I could follow your tutorial with ease. Thank you so much!

  • @dianawestrup7416
    @dianawestrup7416 9 ปีที่แล้ว +11

    Thoroughly explained! Great teacher, thanks very much!

  • @FalsifiedHero
    @FalsifiedHero 13 ปีที่แล้ว +2

    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.

  • @caseystarr
    @caseystarr 14 ปีที่แล้ว

    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!!!!

  • @lucawatkins1772
    @lucawatkins1772 2 ปีที่แล้ว

    khan academy is my saviour, the depth of the explanations are way beyond any professors I've had! Makes me feel like I can take time to understand the material

  • @FatmaMohamed-ck2jz
    @FatmaMohamed-ck2jz 6 ปีที่แล้ว

    I sarcastically said that if i actually understand any of this I would happily give out money to everyone in the world....now I owe each and every one of you! Thank you math teacher guru🙏🙏🙇

  • @jacyleblanc3641
    @jacyleblanc3641 9 ปีที่แล้ว +9

    Tanks man you save my tomorow exam 3

  • @JMfrac
    @JMfrac 13 ปีที่แล้ว +1

    I just finished coding a matrix multiplier from this lecture. Thanks!

  • @zuesr3277
    @zuesr3277 9 ปีที่แล้ว +4

    Because of you I get interest in the learning.

  • @missquprison
    @missquprison 13 ปีที่แล้ว

    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 !

  • @glueee2621
    @glueee2621 8 ปีที่แล้ว +125

    Aliens come down to Earth, they end up waging war with humans over how we operate with matrices.

    • @cat-132
      @cat-132 7 ปีที่แล้ว +1

      Swedish coder agreed

  • @claxemomis5
    @claxemomis5 13 ปีที่แล้ว

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

  • @TheZzzzzzz999
    @TheZzzzzzz999 13 ปีที่แล้ว

    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!!!

  • @jeanotho
    @jeanotho 16 ปีที่แล้ว +2

    first comment, congratulation everybody :D

  • @kenjiroumiyamoto1432
    @kenjiroumiyamoto1432 9 ปีที่แล้ว +11

    Thank you professor! This helped a lot!

  • @fherblog
    @fherblog 7 ปีที่แล้ว

    Very Clear!! excellent! i understand you more than i understand my math teacher even speaking another language!, regards from argentina!

  • @ahmadkfarhat
    @ahmadkfarhat 9 ปีที่แล้ว +76

    -16 +6 is not 10, it's -10

  • @Theroots81
    @Theroots81 12 ปีที่แล้ว

    3 minuets in and you explain it better than a 2 hour lecture

  • @khanacademy
    @khanacademy  16 ปีที่แล้ว +1

    thanks. I added the notation.

    • @Elemenop345
      @Elemenop345 6 ปีที่แล้ว +1

      Khan Academy *annotation
      - Greetings from 2018

  • @nibo1980y
    @nibo1980y 13 ปีที่แล้ว +5

    "I know this is confusing and I feel bad for you right now"
    lol
    thanks sal!

  • @oscarchavez8605
    @oscarchavez8605 11 ปีที่แล้ว

    Your videos have been saving my butt in math all year, thanks for explaining
    the material so well.

  • @mexmas93
    @mexmas93 13 ปีที่แล้ว

    my god man..u make it easier to understand wooow thanks alot..way better than my big belly math teacher

  • @yujinwu
    @yujinwu 15 ปีที่แล้ว

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

  • @pr12812
    @pr12812 9 ปีที่แล้ว +5

    شكرآ على هذا المجهود.. عمل جيد حين ترجمت الى اللغة العربيه@@

  • @TEEHSOO
    @TEEHSOO 13 ปีที่แล้ว

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

  • @soulreaperichig0
    @soulreaperichig0 13 ปีที่แล้ว

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

  • @div_yam2304
    @div_yam2304 4 ปีที่แล้ว

    u r a legend....love from india!

  • @gtrslayer1
    @gtrslayer1 7 ปีที่แล้ว

    Sal... you've saved my *** so many times. I thank you from the bottom of my heart and soul.

  • @woowididit
    @woowididit 9 ปีที่แล้ว +65

    Please don't stop using colours !!!!!!

  • @i650cutie
    @i650cutie 13 ปีที่แล้ว

    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!!!

  • @dufo4766
    @dufo4766 7 ปีที่แล้ว

    You guys are all right! He is a wonderful teacher!

  • @mehedihassanimon6027
    @mehedihassanimon6027 9 ปีที่แล้ว

    Best teacher so far 💔

  • @mehedihassanimon6027
    @mehedihassanimon6027 9 ปีที่แล้ว

    Best teacher so far 💖

  • @stephjones55
    @stephjones55 11 ปีที่แล้ว

    Thanks for explaining it much better than my math teacher!

  • @BeatsDr
    @BeatsDr 13 ปีที่แล้ว +1

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

  • @AJRaj24
    @AJRaj24 9 ปีที่แล้ว +3

    Thank you greatly. You are the best.

  • @da5id6301
    @da5id6301 15 ปีที่แล้ว

    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.

  • @Sokobansolver
    @Sokobansolver ปีที่แล้ว

    Khan Academy: Here, practice this particular type of problem a few times.
    Brilliant: Here's a tweaked, harder version of the previous problem that you had to read the explanation for, or a different problem altogether!

  • @tanatswanhau.1042
    @tanatswanhau.1042 4 ปีที่แล้ว

    You have really helped me a lot😢thank you so much

  • @tymothylim6550
    @tymothylim6550 3 ปีที่แล้ว

    Thank you very much for this video! It really helped to have an example to show how the multiplication works and also why the order in the multiplication matters.

  • @alexgarcia8365
    @alexgarcia8365 6 ปีที่แล้ว +1

    5:01 you should of kept writting the problems before you started solving it will help people understand what to put into the equation

  • @luyangzhong72
    @luyangzhong72 9 ปีที่แล้ว

    Omg.....I feel bad for you 😂😂😂😂he is like the most thoughtful teacher in the world ……hahaha

  • @mapinfoz
    @mapinfoz 7 ปีที่แล้ว

    Great. Thanks again. Now here's a question. Why, when I was in college, didn't the teacher describe it just like this?! Everyone would have understood!
    At least we have khan now

  • @TheCapslockCritic
    @TheCapslockCritic 14 ปีที่แล้ว

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

  • @spartankingnoble
    @spartankingnoble 10 ปีที่แล้ว +10

    Teach me master.

  • @simplyalif
    @simplyalif 15 ปีที่แล้ว

    Thanks soooooo much. God bless your soul.

  • @TheRAVI147
    @TheRAVI147 7 ปีที่แล้ว

    Best channel for me.....

  • @curtpiazza1688
    @curtpiazza1688 ปีที่แล้ว

    Thank you for clarifying this topic! ❤

  • @revincentiii
    @revincentiii 10 ปีที่แล้ว

    He was very thorough. I liked the use of terms row vector x column vector or dot product. He also pointed out that the order makes a difference. You will not receive the same result when you change order.

  • @mohanadmohamed6460
    @mohanadmohamed6460 7 ปีที่แล้ว

    I am a genius :D
    When i added up the answers of the two last examples i got the same answer
    Eg: 23+34+31+46=134
    19+22+43+50=134
    I AM THE NEW SAL :D

  • @1CelloGirl1
    @1CelloGirl1 14 ปีที่แล้ว

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

  • @snottybb
    @snottybb 13 ปีที่แล้ว

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

  • @Konvicted17
    @Konvicted17 9 ปีที่แล้ว

    You are great Mr. Khan

  • @shizarizvi3343
    @shizarizvi3343 6 ปีที่แล้ว

    This guy made my life easier😍

  • @wilsonnguyen8041
    @wilsonnguyen8041 8 ปีที่แล้ว

    'One could define it that way, but that's not the way it is in the real world. And the way in the real world is unfortunately, is more complex." -Khan Academy If only i knew this sooner :(

  • @treyannajarrett8024
    @treyannajarrett8024 4 ปีที่แล้ว

    This is very helpful😫❤

  • @yarpen26
    @yarpen26 6 ปีที่แล้ว

    The matrix multiplication pattern is so counterintuitive, I seriously doubt I'll be able to remember it in the future without looking it up first. It's always gonna be like "Wait, was it the first figure in the first row of matrix A times the second figure in the first row of matrix B or was it a column...?"

  • @Jakers2009
    @Jakers2009 15 ปีที่แล้ว

    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...

  • @gabegutierrez18
    @gabegutierrez18 4 ปีที่แล้ว

    Here I am... in Elementary Differential Equations, just now learning how to use matrices in order to help me solve systems of equations!

    • @cappy8314
      @cappy8314 4 ปีที่แล้ว

      You can do it

  • @5185988519
    @5185988519 15 ปีที่แล้ว

    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)!

  • @Max11551
    @Max11551 16 ปีที่แล้ว

    Really cool you created a Linear Algebra playlist.
    You seem to be running out of space pretty often though, ever considered capturing the screen at a higher resolution?

  • @jadatan1019
    @jadatan1019 12 ปีที่แล้ว

    Omg this is amazing! Im learning this just because its fun!

  • @sontapaa11jokulainen94
    @sontapaa11jokulainen94 6 ปีที่แล้ว

    Great teaching.

  • @guyx5000
    @guyx5000 14 ปีที่แล้ว

    ur saving my life bro

  • @Jaaae00
    @Jaaae00 7 ปีที่แล้ว

    This helped me make sure I wasn't doing it wrong

  • @ThomasGardner12321
    @ThomasGardner12321 12 ปีที่แล้ว

    thanks man this is great for my gcse further maths!!! :)

  • @EngineeringtheFuture
    @EngineeringtheFuture 8 ปีที่แล้ว

    Love your videos Sal! Thank you!

  • @airhead2580
    @airhead2580 16 ปีที่แล้ว

    this video is verrry helpful! thank you!

  • @anumintsky
    @anumintsky 7 ปีที่แล้ว

    Good and very easy technique...

  • @pocallaghan9
    @pocallaghan9 12 ปีที่แล้ว

    Thanks so much, I love maths but matrices was an area I was really afraid of now you have shown we light at the end of the tunnel, thanks this will help very much so in my exams this week!

  • @SergeantNugget
    @SergeantNugget 12 ปีที่แล้ว

    This is really helpful with OpenGL 4.2.

  • @rimzhimshajid
    @rimzhimshajid 13 ปีที่แล้ว

    Thanks for this video! I finally get this!!

  • @pocallaghan9
    @pocallaghan9 12 ปีที่แล้ว

    Im actually getting my results on Wednesday. It takes a long time to pend because I did the Irish Leaving Certificate of exams in 7 subjects including maths. Thanks to you areas like matrices and complex numbers are no sticky areas for me, I also managed to apply for mathematical sciences for uni. What you mean Major?
    Thanks again Khan

  • @elanalancia6746
    @elanalancia6746 8 ปีที่แล้ว

    Helped a lot thanks 😀

  • @omegam9766
    @omegam9766 9 ปีที่แล้ว +9

    ohhh man this is great but your just like Bob Ross from channel 13 I'm going straight to a cat nap. I'll be back lol

  • @johnjames4662
    @johnjames4662 11 ปีที่แล้ว

    Khan rules!!!

  • @malikdayyani6702
    @malikdayyani6702 11 ปีที่แล้ว +44

    I thought that was a 1..... -____-

    • @Brayan-hr9of
      @Brayan-hr9of 7 ปีที่แล้ว +1

      Malik Dayyani same!!!

  • @EquinoxParadox91
    @EquinoxParadox91 13 ปีที่แล้ว

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

  • @tapiwanashekainga1714
    @tapiwanashekainga1714 6 ปีที่แล้ว

    This was so helpful .... Thanks

  • @companymen42
    @companymen42 12 ปีที่แล้ว

    your two looked like a 1 and I was like, "WHERE ARE YOU GETTING 2 FROM" lol this helped alot

  • @LLaPThor
    @LLaPThor 11 ปีที่แล้ว

    Thanks for this, great video. I had to backtrack at the start because the 1st Row, 1st Column matrix looked a lot like a 1 to me and 2 was repeated a lot. Great way to revise matrices though.