Introduction to linear independence | Vectors and spaces | Linear Algebra | Khan Academy

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  • Опубліковано 8 жов 2009
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    Introduction to linear dependence and independence
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    Linear Algebra on Khan Academy: Have you ever wondered what the difference is between speed and velocity? Ever try to visualize in four dimensions or six or seven? Linear algebra describes things in two dimensions, but many of the concepts can be extended into three, four or more. Linear algebra implies two dimensional reasoning, however, the concepts covered in linear algebra provide the basis for multi-dimensional representations of mathematical reasoning. Matrices, vectors, vector spaces, transformations, eigenvectors/values all help us to visualize and understand multi dimensional concepts. This is an advanced course normally taken by science or engineering majors after taking at least two semesters of calculus (although calculus really isn't a prereq) so don't confuse this with regular high school algebra.
    About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content.
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КОМЕНТАРІ • 149

  • @RJA10001
    @RJA10001 7 років тому +571

    you've helped me in grade 8 math, which was 6 years ago. Here I am in 2nd year university, and you're still helping me, but now I'm getting a math minor. =D

    • @godson200
      @godson200 3 роки тому +8

      You just reminded me of when I was in 8.

    • @SokumenTop
      @SokumenTop 2 роки тому +1

      Same here 5 years after you

    • @AshokKumar-ix4nf
      @AshokKumar-ix4nf 2 роки тому +5

      @@SokumenTop now i will comment in 2026 😂

    • @naman4067
      @naman4067 2 роки тому

      I will comment on 2027

    • @aykuttosun4607
      @aykuttosun4607 Рік тому +4

      Greeting 🙂How was it? Are you happy yo get a math minor after 6 years later?

  • @RobynHode8
    @RobynHode8 10 років тому +135

    Sal Khan is invaluable to mankind.

  • @Knot2goodAtIt
    @Knot2goodAtIt 9 років тому +116

    This guy is such a beast.... so many people would have failed their classes without him lol

  • @vonStalhein2
    @vonStalhein2 8 років тому +33

    Albert Einstein said(in relation to what genius means), "It should be possible to explain the laws of physics to a barmaid." Sal is a living example of that.

  • @khanacademy
    @khanacademy  15 років тому +50

    It is usually introduced in 10th or 11th grade in Algebra II or Pre-calculus.

  • @xxemilyannexx21
    @xxemilyannexx21 12 років тому +3

    You are a godsend! I have spent all year learning about matrices and eignevalues and linear algebra and partial derivatives and not understood. i have spent 3 days watching your videos and it is clear now! thank you soooo much!

  • @mohinikaur9463
    @mohinikaur9463 8 років тому +2

    I really prefer long videos where an in-depth analysis of the topic is done. 15-20 minutes is good to take. Thanks for great stuff!

  • @eman5300
    @eman5300 3 роки тому +8

    Sal my bro you are the king never met you but you one of my dearest mentors 💯 helped me through education and both life 😭😂 keep this dream alive once I graduate imma try to join your team and keep your approach to education alive

  • @wingbaby28
    @wingbaby28 7 років тому +3

    Thank you for making these great videos!! I am taking linear algebra, and the way my professor explains those concepts is very hard to understand. I feel way better after watching your videos.

  • @yeonhyungjun674
    @yeonhyungjun674 2 роки тому +5

    You are like life saver of my intellectual journey.
    I got into physics 3 months ago, and I learn all sorts of calculus with you and khan academy, and now I am learning linear algebra.
    first I tried to study this new subject with books, then I got frustrated cus I didn't understand any of explanation and proof in the book.
    but now after watching this lecture, what's in the book started to make sense!!!

  • @MohaMMaDiN55
    @MohaMMaDiN55 5 років тому +4

    Where ever I go to a scientific youtube channel, I will never find someone who is more satisfying than you.
    Your channel is the best according to my experience of watching so many scientific vids on youtube.

  • @iamabean
    @iamabean 9 років тому +44

    Khan , Thank you so much for all the videos. After watching your videos,I just realize how stupid I was when I spent my time reading the god damn linear algebra textbook. Your explanation is very concise but very informative

    • @KabooM1067
      @KabooM1067 8 років тому +15

      Math textbooks are the worst at teaching math I swear to god I. Never benefited from them except the exercises. ._.

    • @twonulator
      @twonulator 7 років тому +10

      James Stewart Calculus and Saxon Algebra series are the only books worth a damn. The rest can be committed to the flames.

    • @vivienne_lavida
      @vivienne_lavida 7 років тому +5

      Yes, James Stewart is the best calculus book out there.

    • @saviourmukuka2833
      @saviourmukuka2833 5 років тому

      Kkkkkk just like me 😝😂

  • @ProTawN
    @ProTawN 9 років тому +18

    This guy can explain all of this so much better than my Professor....
    thank you so much!

    • @Peter_1986
      @Peter_1986 8 років тому +4

      +ProTawN
      *Typical professor:*
      "Today we are going to introduce New Concept. :-|"
      "This New Concept is defined by the general formula written on the board. :-|"
      "Okay, so here is one example. :-|"
      *Khan:*
      "Hello. 8-) ♪"
      "Let's talk about New Concept in this video."
      "So let's say I had... I don't like this color... oh well, anyway, it will do the job. 8-)".

  • @onlyAerik
    @onlyAerik 14 років тому

    I especially appreciate some of this vector-centric teaching, and especially the matrices. I just got to a point in one of my electricity textbooks where I'm defining instantaneous values of waveforms as vectors, and they went through it fast and weird.

  • @KingIDMF
    @KingIDMF 12 років тому +3

    I have a linear algebra midterm tomorrow, you're my saviour sir.

  • @aadityagupta6838
    @aadityagupta6838 2 роки тому

    O god! U listened to me 😇Being Maths hons. Graduation student i was really struggling with this algebra n these videos of yours turned out to be miracle for me.. Thanx khan academy, u really cleared my concepts...

  • @uclocnguyenvo422
    @uclocnguyenvo422 5 років тому +4

    his voice is addictive :) god level of inspiration

  • @FilipePauloMax
    @FilipePauloMax 14 років тому

    Thank you very much...something that was very abstract for me, now no matter what exercise you give me, i can THINK right and solve it not with formulas but with your explanations :) thanks a lot you should be paid for that!

  • @Waranle
    @Waranle 15 років тому

    Thank you, Thank youuuuuuuuuuuuu Sal, To start again posting these Linear Algebra. All i needed.... great.

  • @BARaaz04
    @BARaaz04 5 років тому +1

    Hey Sal, you are fantastic. You have god gifted teaching style.

  • @skaai
    @skaai 14 років тому +1

    you are awesome sir! for those of us who are up studying at 3:30am, you are a godsend! not to mention you should rename your name from khanacademy to linearalgebrafordummies! keep breaking it down for us non-mathematics dummies! plenty of us like math, but don't speak "math" natively...

  • @mohammedishfaqmostain4835
    @mohammedishfaqmostain4835 2 роки тому +1

    I can’t believe I am still talking help from this guy even in uni

  • @gazmaska7593
    @gazmaska7593 9 років тому +7

    THANKS KHAN!!! IN 6 minutes you made it clear for me waht SPAN means!!!! My teached wasn't able to do so neither the book!!! YOURE A GENIOUS

    • @pleaseenteraname1215
      @pleaseenteraname1215 5 років тому

      It's been 4 years but i think you should see 3blue1brown's video he has great math content he also used to work at khan academy

    • @nizarch22
      @nizarch22 3 роки тому

      @@pleaseenteraname1215 lol he probably graduated college and now has kids, but sure 3blue1brown is great.

  • @relentlessfella
    @relentlessfella 12 років тому

    Thanks dude... this is the best explanation of the concept so far and it was very much comprehensible =)

  • @alexgomez4525
    @alexgomez4525 7 років тому

    Thank you man, you have made me understand this, much better than my teacher

  • @kheo46
    @kheo46 3 роки тому

    brilliant video, laid out the fundamentals well

  • @skkamalshah
    @skkamalshah 6 років тому

    Half of the semester gone, I learned absolutely nothing. today, before 2nd mid linear algebra started making sense to me from ur videos. Thanx man!! Take a bow!!!

    • @iLoveTurtlesHaha
      @iLoveTurtlesHaha 6 років тому +1

      OMG, I'm in the same boat as you. I hope I don't fail L.Alg. :(

  • @ruggerobenetti8770
    @ruggerobenetti8770 5 років тому

    These videos are dope. Thank you so much

  • @sarvanray3971
    @sarvanray3971 3 роки тому

    Very to the power infinity nice video.. really u r teaching style is unique as well as best. U teach this using its practical significane and imagination and exactly is my way of learning anything and everything

  • @MrWaqasyaqoob
    @MrWaqasyaqoob 14 років тому

    you a very good teacher ,
    i like your teaching style very much .
    You are doing great work ,
    thanks

  • @fitnesschannel9070
    @fitnesschannel9070 2 роки тому

    Sal, you're a God's gift. And that's not an exaggeration. Seriously. How is your existence possible...

  • @wajyt312
    @wajyt312 11 років тому

    thanks! its much more understandable when u draw it out. unlike my lecturer...

  • @micahtonning7967
    @micahtonning7967 5 місяців тому

    Thank you for posting.

  • @peters.9371
    @peters.9371 4 роки тому

    the terminology was confusing me, until you explained it properly, thanks!

  • @davin7151
    @davin7151 7 років тому

    An alternative way of showing that any two non parallel vectors a, and b have a span of the whole cart. plane is to first pick an arbitrary point denoted x,y, then draw a vector b * inf through that point, where 'inf' = infinity. I.e. infinitely long line through the point. Then you can show that a * inf passing through origin will always intersect with b * inf passing through the point, since non parallel lines always meet.

  • @Zerpentile93
    @Zerpentile93 11 років тому

    You explain it very well :).

  • @Hercules003
    @Hercules003 4 роки тому +8

    My uni professor and GTA failed to teach me this simple thing- I thought I was stupid! In 15 minutes, I have realised I am not stupid.

  • @ReneUlloa74kg
    @ReneUlloa74kg 6 років тому

    I love you. I am in grad school at NYU for econ and you are better than the book.

  • @asif7240
    @asif7240 Рік тому

    Thank you!

  • @studysmartderps7305
    @studysmartderps7305 Рік тому

    Returning student and forgot a huge chunk of math even basic algebra😅. But still able to keep up because of youtube straight to point explanation.

  • @thenekoling
    @thenekoling 13 років тому

    thank you!

  • @RangeK1D
    @RangeK1D 11 років тому

    I am in Uni now, I see why people come here, your saving my Linear Midterm today :)

  • @MrDannyX3
    @MrDannyX3 5 років тому

    Thank you so much!

  • @mangathayarumaddukuri2709
    @mangathayarumaddukuri2709 4 роки тому

    Great explanation

  • @KydroxHD
    @KydroxHD 6 років тому +11

    0:04 乇乂ㄒ尺卂 ㄒ卄丨匚匚

  • @42muslimah
    @42muslimah 12 років тому

    aww, thanks for noticing Sal! I had noticed that videos were getting pretty long, but they're still super helpful, so I didn't wanna say anything. :)

  • @extraterrestrial16
    @extraterrestrial16 9 років тому

    Should there have been '+' and '-' signs for the R set notation to specify the directionality of the vectors (vector space) ??
    Given that the two vectors were either in the positive or negative planes..

  • @Vivekanand44
    @Vivekanand44 5 років тому

    Very useful

  • @ahmedaltalib5981
    @ahmedaltalib5981 11 років тому

    Tnx, it is now easier.

  • @imyafatha999
    @imyafatha999 9 років тому +20

    "i don't wanna do it that thick" - salman khan

  • @Xlaxsauce
    @Xlaxsauce 14 років тому

    you make much more sense then my professors.

  • @prominence1351
    @prominence1351 8 років тому +79

    "I want to get back into habit of making shorter videos"
    Next video is 2 minutes longer

  • @luayabd
    @luayabd 14 років тому

    thank you very much

  • @user-ko5il5bo6c
    @user-ko5il5bo6c 2 роки тому

    linearly dependent means that one of the vectors in the set can be represented by some combination of the other vector in the set

  • @girlonlaptop
    @girlonlaptop 13 років тому

    thanks!

  • @sherjr7406
    @sherjr7406 11 років тому

    you're amazing.

  • @hemaniprincy5226
    @hemaniprincy5226 6 років тому +1

    Hi sir. This is the first time I am watching your tutorials. They are quite interesting. But I have a doubt in the span of linearly dependent and independent set
    Linearly dependent vectors spans lie over a straight line. And linearly independent spans R2 r8..... However when we considered the set of three vectors where 1 is a linear combination of the other two.....they are linearly dependent r8.... Then how come their span is R2. The concept is clear.....but I am getting confused in identifying the linear dependent and independent vector.....

  • @Gommaq
    @Gommaq 14 років тому

    Thank you :)

  • @ChatGPT-
    @ChatGPT- Рік тому +1

    Bro explained this all when I just started going to school 😭❤️

  • @tangoforthemango
    @tangoforthemango 13 років тому

    this is awesome

  • @SahibzadaInstitute
    @SahibzadaInstitute 7 років тому

    Beat of luck my dear sir >>>>>

  • @TheJuga
    @TheJuga 13 років тому

    Thanks man the Berkeley textbooks are sort of convoluted

  • @7angels844
    @7angels844 17 днів тому

    as long as the only linear combonation for v1 and v2 that equals 0 is when c1 and c2 is 0 then v1 and v2 are linearly independant and span V

  • @Peter_1986
    @Peter_1986 8 років тому

    @gommaq Hus
    You mean "redundant", right?
    It means that something doesn't have any meaningful purpose, and that you can safely ignore it.
    For example, you only need two 2×1 vectors to specify a point in ℝ², so any extra vectors will thus be redundant, since they are not necessary at all.

  • @divvelaharsha826
    @divvelaharsha826 5 років тому

    good explanation

  • @kayrstar8965
    @kayrstar8965 3 роки тому

    Thank u

  • @miekzand
    @miekzand 10 років тому

    Amazing video's! You already helped me out with Biology, Chemistry and now with Math. Thanks :)

  • @excalibercuberdavid4681
    @excalibercuberdavid4681 3 роки тому

    Im watching this in 2021. I was 7 when you created this video.

  • @jishuenkam
    @jishuenkam 13 років тому

    @bernicedan well we do have some matrices in moderm math

  • @MegaBugBugBug
    @MegaBugBugBug 11 років тому

    Yeah that had me confused at the start as well. Go to his first video where he tells that this is just a way of representing data he could be doing it like [0,2] or like (0,2) even if its a column it is just basically the same thing. If you take [0,2] and turn it on top so that 0 is at the top it's all good. I say stick with how your teacher does it they will probably prefer it in tests. I think he just does it like this to prepare people for matrix which are later on.

  • @mlaumusic
    @mlaumusic 7 років тому

    You're awesome

  • @guscosta1
    @guscosta1 13 років тому

    you make much more sense than my professor and I dont even speak english

  • @astrophy1586
    @astrophy1586 3 роки тому

    Those who have put a thumb down are really buffoons.. No one can explain simpler than this man😍

  • @quidquopro1185
    @quidquopro1185 8 років тому +1

    The guy that do thease tutorials, does he also do Dark Souls walkthrough? The voice is identical!

  • @KodiBrehdon
    @KodiBrehdon 11 років тому

    anybody know the software, that are used for sketching (black background, etc)? thank you

  • @estidavezi5825
    @estidavezi5825 8 років тому

    Thank you it turned out to be very helpful :D

  • @fahimally3923
    @fahimally3923 3 роки тому +1

    YOU GOING TO HEAVEN AND I'LL MEET YOU THERE. THANKS

  • @maven12LA
    @maven12LA 3 роки тому

    Sal khan is GOAT

  • @EugenioMejia
    @EugenioMejia 13 років тому

    what program do you use?

  • @tedtdu
    @tedtdu 8 років тому

    What if R^5? so they can't be expressed by X,Y Coordinated graph? Will you please shed some light please.

  • @qualquan
    @qualquan 2 роки тому

    Just re-discovery of head to tail vector combination using bunch of novel terms.
    Old wine in new bottles.

  • @shengzhou6170
    @shengzhou6170 5 років тому

    Wait if the matrices written in orange are linearly independent how is it that they are able to still represent anything in R2? so what's the difference between linearly independent and dependent

  • @meinankitv4766
    @meinankitv4766 4 роки тому +4

    Give this guy my college tution fee..

  • @thetruereality2
    @thetruereality2 8 років тому

    Does this mean that any two set of vectors in a two dimensional plane can span that plane? 5:26 -6:20 Thank you for an amazing explaination

    • @joyzhou4917
      @joyzhou4917 8 років тому

      Actually, no. If a pair of vectors in a two dimensional plane are linearly dependent, then they cannot span that plane.

  • @lynsikeye3714
    @lynsikeye3714 5 років тому

    Question: Why is it relevant if they are linearly independent or not? Take the first example, even if they were independent, because there isn't a z-component of the vector, it will always only be on the R2 span.

    • @MrMereum
      @MrMereum 5 років тому

      becomes relevant later on for finding null space basis i think

  • @rnibir2769
    @rnibir2769 Рік тому

    5:00

  • @PhilNailedIt
    @PhilNailedIt 12 років тому

    Awesome video, better than 'sneezing panda.'

  • @liverpoool4lyf
    @liverpoool4lyf 12 років тому

    woow, i'm studying it now for my Computer Science degree...Thumbs up if you are to!

  • @Jack-cm5ch
    @Jack-cm5ch 6 років тому

    6:40

  • @deephknallareddy6670
    @deephknallareddy6670 8 років тому

    span the splane

  • @dfsfklsj
    @dfsfklsj 11 років тому

    Mathematics is the same anywhere in the world... It's not like languages that change dependent on country.

  • @jaytaffer9641
    @jaytaffer9641 3 роки тому +1

    My gf asks, "Is that a linearly independent vector or are you just happy to see me?"

  • @taekwonwelchify
    @taekwonwelchify 12 років тому

    DUDE.... YOUR THE SHIT. YOU JUST GOT THE NATURAL TEACHING SKILLS... LOL FOR REALS.

  • @arpithams
    @arpithams 13 років тому +2

    what abt vectors[7,2] and [2,3] are they linearly independent..

  • @caseclosed2519
    @caseclosed2519 7 місяців тому

    hey look there's a pivot column in every column when it's linearly independent. we're learning woo

  • @nidhishgautam9043
    @nidhishgautam9043 9 років тому

    Sal is the saviour of 99%. Humanity. Except for those 1% >140iq

  • @trollzeus8288
    @trollzeus8288 7 років тому +2

    how can the whole R2 plane be represented by a linear combination of just 2 vectors? the 2 vectors are essentially 2 lines no? Then how can every point in the 2 dimensional plane be represented by just 2 lines?

    • @dormoshe4237
      @dormoshe4237 7 років тому +3

      You can add a part of the vector to another part of the other vector, for example, if you have (0,1) and (1,0), by adding them n times you reach (n,n). Notice that n stands for any real number. Also, you can add one of them n times and them other m times. This way you can reach any point on the plane

    • @trollzeus8288
      @trollzeus8288 7 років тому +2

      Oh so, the 2 lines can be "scalarly multiplied" to represent any point in a plane?

    • @dormoshe4237
      @dormoshe4237 7 років тому +3

      Exactly. This is not always the case, try watching the linear dependent and independent videos

    • @trollzeus8288
      @trollzeus8288 7 років тому +2

      Dor Moshe perfect. Thank you!

    • @brucelee8318
      @brucelee8318 5 років тому

      👍

  • @highestintheroom-podcast741
    @highestintheroom-podcast741 2 роки тому

    when you said "those three guys" you remembered me 3blue1brow..

  • @amairanas8631
    @amairanas8631 3 роки тому

    007 bond!!

  • @ojasmeshram3369
    @ojasmeshram3369 6 років тому

    Aslam
    Vale
    Kum