Orthogonal complements | Alternate coordinate systems (bases) | Linear Algebra | Khan Academy

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  • Опубликовано: 15 сен 2024
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    Orthogonal Complements as subspaces.
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Комментарии • 57

  • @MadsWest
    @MadsWest 3 года назад +8

    Sal is the king of explaining maths to everybody in my book. Can't imagine how many individuals he has helped this way. Really nice with repetition of what elements in the transposed matrix are dotted with what elements in the vector. I know this is very elementary, but for some reasong I find it hard to recall every time I'm calculating this manually and in terms of understanding what is actually happening behind the scene.

  • @twonulator
    @twonulator 7 лет назад +85

    For those complaining that these videos contain too many proof style lectures, it is because they are intended for university level instruction where proofs are required comprehension.

    • @rubanpillay
      @rubanpillay 7 лет назад +5

      twonulator true. I got this topic in a test tomorrow and it alone has 19 proofs

    • @tiabarber4312
      @tiabarber4312 7 лет назад +6

      twonulator proofs help, but examples help the proofs "stick"

    • @iLoveTurtlesHaha
      @iLoveTurtlesHaha 6 лет назад +2

      Also, they need not pay attention to those parts, if all they want is to do it, they can just take away those parts. Geez, people are so dumb sometimes.

    • @edwalkcow8214
      @edwalkcow8214 6 лет назад +15

      with that being said, if we need proof style lectures, it already existed in the lecture notes. but we didn't understand the lecture, thats why we are here, we are looking for alternatives.

  • @AsadAli-rd2mk
    @AsadAli-rd2mk 4 года назад +10

    This channel is way ahead of the current time

  • @artema5535
    @artema5535 9 лет назад +21

    don't know why all people you keep blaming on sal's lecture. I thought this lec made a lot of sense to me and he did his job well. He does not prepare his lectures but does straight on the fly from his mind . so please respect that and do not say: " "uhmm write it like... lemme write it like"""... typical nonsense ignorance. If you don't like it, then skip it. There are tons of similar videos on this topic on youtube to watch.

    • @rafiy7150
      @rafiy7150 3 года назад

      agreed I still remember in my uni basic physics course the lecturer made me memorize all the formulas, then I decided to learn in khan academy and I dont really have to memorize anymore they just stick in my head because I know the analogy where they all come from

  • @nils123007
    @nils123007 3 года назад +1

    This video is nine Years old. Yet, it's more comprehensive and easier to understand than most lectures out there...

  • @CoolDude911
    @CoolDude911 12 лет назад +5

    The 0 vector being in the set needs to be shown just to show the set is non-empty the first two properties hold for the empty set.

  • @Barba_007
    @Barba_007 4 года назад +3

    quick recap : null space of (A) is the orthogonal complement of the subspace spanned by row elements of A (or subspace of colum elements of A transposed)... thank me later

  • @ibnsweeney
    @ibnsweeney 10 лет назад +34

    why dont you do an example?

  • @VishyKc
    @VishyKc 12 лет назад +4

    It's linear algebra. I study this in Croatia at the college right now and it is pretty awesome.
    Go to college of mathematics, you'll learn super interesting things. Programming is cool too ;)

  • @davidk7212
    @davidk7212 5 лет назад +1

    If you're searching RUclips specifically for how to compute/solve such things with no interest in the theory or the "proofy" aspects of it, you're wasting your time. You shouldn't even be taking whatever course you're taking because all you're going to "learn" is how to inefficiently do what Mathematica can do, and you'll forget it within a few months anyway. Even if this is just for some prerequisite you need, you need it for a reason and should take it seriously.

  • @wsmao1154
    @wsmao1154 7 лет назад

    it's very clear to understand why we have this property ! it's help and thanks for doing this ! really appreciate it !

  • @danishfella
    @danishfella 14 лет назад +2

    V perp, not for perpetrator, but for PERPENDICULAR!

  • @AvivAtias
    @AvivAtias 13 лет назад +1

    @comecra85 In fact, as much as I know (weird terminology...) "these things", meaning the whole formalization and exploration of the algebra of the 1 and 2 dimensional mathematical objects: vectors & matrices consisting Linear Algebra, are the building blocks for "other things" investigated by natural sciences, which doubtlessly help to solve a wide variety of real life problems (consider the microwave). Anyway, whether you believe it or not, some people (like me) actually enjoy these inquiries.

  • @thelastcipher9135
    @thelastcipher9135 8 лет назад +2

    one tip. always have a pen and paper beside to use and rewatch over and over til everything sinks in - don't give up

  • @BrotherOfHercules
    @BrotherOfHercules Год назад

    You are the best teacher in the world.

  • @terence321
    @terence321 Год назад

    This is an excellent explanation and proof

  • @gianlucacastro5281
    @gianlucacastro5281 3 года назад

    Sal once again bringing the knowledge we need

  • @jonathanjordan21
    @jonathanjordan21 2 года назад

    9:45
    I think it shouldnt be a transpose since its a dot product.
    vector X order is m x 1

  • @sohjunwen5490
    @sohjunwen5490 11 лет назад +1

    THANK YOU SAL!

  • @HoloUniverse
    @HoloUniverse 14 лет назад +1

    Thank you!

  • @mahlejas
    @mahlejas 14 лет назад +1

    it is not so important but at 10:26 Rn sould be that Rm.
    FYI.
    Thanks for your videos they are so helpful.

  • @user-wr6ek9fx1x
    @user-wr6ek9fx1x 6 лет назад +2

    10:14 that should be row-m?

  • @天也-w9x
    @天也-w9x 2 года назад

    linear algebra is very difficult

  • @grimmovers
    @grimmovers 14 лет назад

    thnx

  • @hcsquad7357
    @hcsquad7357 2 года назад +1

    Can I download the board?

  • @TheBetterGamer
    @TheBetterGamer 13 лет назад

    Hey did you know you can have 4 orthogonal lines?
    It's possible. Go ahead, think about it for a bit.

    • @SpotlessWanderer
      @SpotlessWanderer 4 года назад

      x=y=z, x=-y=z, -x=y=z and -x=-y=z ? For example..

  • @astinmartindriver
    @astinmartindriver 10 лет назад +5

    Too proofy.

  • @Barba_007
    @Barba_007 4 года назад

    same notation for row and col spaces dude, you can easily get lost here

  • @kanamei9170
    @kanamei9170 7 лет назад

    Both Chinese subtitles are wrong. please fix it.

    • @FungwaaTongwan
      @FungwaaTongwan 4 года назад

      still wrong now 复制粘贴什么玩意QAQ

  • @sirfalcon1
    @sirfalcon1 10 лет назад +11

    Way too proofy. I just need to know how to find the orthogonal complement. Do an example or something.

    • @landonbarnett4865
      @landonbarnett4865 8 лет назад +8

      +Lord Falcon It appears to be aimed at university level, since proof is important when trying to truly understand something. If you just need examples, look for lower level videos...

    • @DarknessIsThePath
      @DarknessIsThePath 7 лет назад +7

      Except proofs barely mean shit on exams.

    • @tordurhansen333
      @tordurhansen333 7 лет назад +1

      Depends on the exam. We prove loads of stuff where I'm attenting, even in exams.

    • @landonbarnett4865
      @landonbarnett4865 7 лет назад +1

      Tordur Hansen I agree, here in Italy 50% of the exam is oral in which only theory and proofs are asked.

    • @jonaskatona7136
      @jonaskatona7136 7 лет назад

      Proofs are essential (and usually required) in more advanced math courses. Even in the first linear algebra course at my university, on both of our ten-question midterms, two or three of the questions were proofs. In the second, more advanced one, it's ~80% proofs.

  • @keremkurban8156
    @keremkurban8156 8 лет назад +1

    Even though being 22 mins of video, its only equivalent to less than 11 minutes since everyting is repeated more than twice. Annoying!! But thx for effort

  • @Soymilllk
    @Soymilllk 15 лет назад +1

    i dont like the new writing style! i miss the cool old pixelated numbers and diagrams!

  • @erithug
    @erithug 12 лет назад

    very lame joke he said!

  • @Krazyerd
    @Krazyerd 10 лет назад +2

    Getting seriously annoyed by the "uhhm lemme write it like.. lemme write it like...". Literally took up 5 minutes of the video.

  • @cha81153
    @cha81153 10 лет назад +4

    BORING!

  • @hossamarafa705
    @hossamarafa705 5 лет назад

    what a waste of time