Basis of a subspace | Vectors and spaces | Linear Algebra | Khan Academy

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  • Опубліковано 8 жов 2009
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    Understanding the definition of a basis of a subspace
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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.
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КОМЕНТАРІ • 209

  • @Deuterium52
    @Deuterium52 8 років тому +332

    You are such a phenomenal teacher sal. You explain things more clearly than most college professors. Linear algebra is considered abstract to us undergrads, which it is, but you illustrate things so clearly. It reminds one that mathematics is rooted in logical reasoning and natural deduction. The way you explain things, everything is logical. So thank you very much for these videos.

    • @GameIsMyOxygen
      @GameIsMyOxygen 7 років тому +3

      Totally agree,he is one of the best teachers. Whenever i am confused about something,and if he has a video on it (which most of the time he has),by the end of the video it feels too easy. xD

    • @Abdul_Rehman6162
      @Abdul_Rehman6162 6 років тому +1

      The best method of explanation.
      I cleared my Vector Space Concepts

    • @fermidirac8904
      @fermidirac8904 5 років тому

      math is not logical what are you saying

  • @khanacademy
    @khanacademy  15 років тому +112

    Most everyday jobs really don't require you to know what these things are. If you enter any scientific/academic field, the ideas of basis and subspace show up a lot. I've also had to use these ideas when I worked at a hedge fund (when we discuss "factors" that can explain movement of a portfolio--the factors are the basis vectors and the universe of potential portfolio performances is the subspace that it should span)

  • @elecengrmka
    @elecengrmka 12 років тому +16

    I could not understand anything in 6 classes of linear algebra in the university but few hours watching your clips have made everything crystal clear. May Allah bless you!

  • @RiarArt
    @RiarArt 12 років тому +63

    OMG i learned 10 times more in 19 min watching this video than in last 2 weeks of Linear Algebra classes at University xD

    • @nikitakundu2444
      @nikitakundu2444 3 роки тому +1

      Couldn't agree more!!! I'm a 2nd time grad student and finally getting a grip on this topic!!

  • @danielgonzalezisaiev9643
    @danielgonzalezisaiev9643 11 років тому +16

    Dear Mr. Khanman,
    Thanks to you, I have realized that when I grow up I want to be LINEARLY INDEPENDENT!

  • @Indianbutler
    @Indianbutler 8 років тому +11

    Thank you Sal:)! If only professors could explain and teach as you do. Again thank you so much for all the video

  • @abhinavkumarsingh6319
    @abhinavkumarsingh6319 7 років тому +38

    Thanks a ton from the bottom of my heart to make such amazing and outstanding videos.

  • @MexterO123
    @MexterO123 13 років тому +2

    I have an exam on wednesday, and with your help. I am confident in answering whatever my teacher gives in the Exam. This is was the first math class I actually was sort of lost in, and you have shown me the light. From now on your my teacher for higher level math.

  • @mikohayle
    @mikohayle 13 років тому +6

    No one has explained this concept better than you! Thank you for all of your videos!

  • @MaroLuva
    @MaroLuva 10 років тому

    That is the clearest definition of a basis I have heard in ANY college course I've had (including a whole semester of topology after linear algebra)

  • @mdib2001
    @mdib2001 4 роки тому +19

    Everyone: His teaching is phenomenal.
    Me: He always takes good colors. ✌😎

  • @agentoranges
    @agentoranges 7 років тому +2

    incredible. I took linear algebra last year and failed it hard. This time around, your explanations constantly make lightbulbs pop up in my mind.

  • @jeniferjanet4809
    @jeniferjanet4809 9 років тому +36

    You the real MVP

  • @alastairzotos
    @alastairzotos 14 років тому +1

    You make math fun, because it feels good when everything just clicks in my head.
    Seriously, you actually make it easy.

  • @mdrakibhossain2433
    @mdrakibhossain2433 2 роки тому

    You did a great job man.Fully understand the concept just in a few minutes which i didn’t in the whole last few years.

  • @fuahuahuatime5196
    @fuahuahuatime5196 10 років тому

    For real... I love how this guy teaches. Thank you so much.

  • @TravisLRoss
    @TravisLRoss 14 років тому

    Sal, just wanted to say thanks. I have been using these videos for understanding how to do singular value decomposition in my graduate level cognitive science course. This sort of stuff appears when modeling how the brain might process information retrieval and how search engine algorithms work. It is definitely not my favorite section of the class, because LA is conceptually hard if you have never seen it before. I am going to recommend these be included in our syllabus for future students.

  • @STgauss3268
    @STgauss3268 2 роки тому +1

    This is treasure man, why in the world have I missed your lectures all this time?

  • @zoomboy6676
    @zoomboy6676 2 роки тому

    All I can say is THANK YOU!!!!!!!!! You are the best prof for explaining linear algebra. Period

  • @ruidechen
    @ruidechen 8 років тому

    Based khan academy! Finally understand this, not the abstract definition but actual examples and explanations :) If I only found you before my mid terms :(

  • @rdzdrd0
    @rdzdrd0 10 років тому +3

    Khan saves the day again!

  • @allthingsacoustic
    @allthingsacoustic 13 років тому

    Thank you for this video!! You just clarified a topic for me that had me completely lost.

  • @sudupati
    @sudupati 14 років тому

    Absolutely brilliant Sir. no more words to describe...

  • @ArchilonValdir
    @ArchilonValdir 9 років тому

    Thanks for this! I really needed a refresher!

  • @3hz3zv4eey6v
    @3hz3zv4eey6v 12 років тому

    This is better than my professor, textbook, and classmates combined. Thank you.

  • @strwbrryshrtcke
    @strwbrryshrtcke 14 років тому

    Thank you soooo much, this helped alot! You made it so easy to understand too

  • @fspopshovit
    @fspopshovit 11 років тому

    Thanks for these video's, they helped me a whole bunch! Too bad I found them so late, my exam is in 2 days! Keep up the good work though

  • @bjarktron
    @bjarktron 11 років тому

    I think my professor tries to make this as complicated as humanly possible with his explanations... thanks for the simplicity!

  • @Ayplus
    @Ayplus 13 років тому +2

    @norwayte . I think these r vital in higher level physics, engineering and vector calculus. I dont think anyone uses these 'day to day' unless u teach it @ a university but in advanced science fields when dealing with many variables and dimensions its necessary.

  • @omerbirinci1691
    @omerbirinci1691 5 років тому

    Thank you. Very clear explanation about relation between span and basis.

  • @Danfranschwan2
    @Danfranschwan2 13 років тому

    you´re so an awesome teacher .... incredible

  • @tuoyazhuo8063
    @tuoyazhuo8063 6 років тому +1

    The video explains the subject matter very well. However, when solving for the vector equation @7:20 (or when determining if the equation has a trivial solution), I think it is better to use augmented matrix instead of plain equations...

  • @jonathansweet2230
    @jonathansweet2230 4 роки тому +1

    Thank you for helping me figure things out!

  • @keziah9798
    @keziah9798 3 роки тому

    hi, i just wanna say thank you for the video, it helps me understand better than my professor and my textbook

  • @nasifhossain3441
    @nasifhossain3441 3 роки тому

    The best video for understanding what the basis is!

  • @yarashamali8061
    @yarashamali8061 8 років тому +15

    his voice

  • @smhassanr
    @smhassanr 13 років тому

    i appreciate this so much, thank you khanacademy

  • @rochranomajeccavea
    @rochranomajeccavea 11 років тому +2

    Thanks! i am absent for a week i our linear algebra class. :) So! thanks a lot! GODBLESS

  • @azrnzala
    @azrnzala 10 років тому

    great video to jog my memory :) thanks.

  • @initrunlevel0
    @initrunlevel0 12 років тому

    thanks mr. khan, i am ready for linear algebra quiz tomorrow :)

  • @dawagyel
    @dawagyel 12 років тому

    thank you so much... u have always been life saver for me.. u are really the best

  • @Rovshenification
    @Rovshenification 8 років тому

    I'm a lazy to research something about Basis or anything about that but I think if I will watch your all lessons I will be lazy as always because everything is about linear algebra is in your channel. This is enough for me to do not any research about anything. Just click your channel and enjoy :D Thanks a lot!

  • @tis_i_sana
    @tis_i_sana 2 роки тому +1

    Just a note: at 06:55 when he checks if they span R2 and then if they are linearly independant; this part is a little excessive. We can achieve the same thing by only checking if they are linearly independant and if they are then they must span R2

  • @Cliff86
    @Cliff86 10 років тому +8

    You should've mentioned that the basis of R^n will always only contain n vectors

    • @Sporky0000
      @Sporky0000 9 років тому +1

      Thank you for mentioning this! I was wondering if the minimum number of vectors that forms a basis was 2, but now I see it depend on the dimension.

  • @greenapplefever
    @greenapplefever 14 років тому

    These are great videos. Excellent job.

  • @linleybaruch738
    @linleybaruch738 3 роки тому +3

    I've got this in my finals tomorrow, and need to re-learn the whole topic because it's been a few years since I've last done it..
    Thanks for this :)

  • @norwayte
    @norwayte 15 років тому

    Thanks. That's what i wanted to hear. - Sounds like analogies of ideas. Even better - patterns of ideas which fit in every subject of human life. In this case... take something of something bigger, make assumptions about it, act with these assumptions and maybe you get a result that you can use for.. for instance to bring in more light in this "something bigger". Or anything else. Ideas are ideas are ideas. In this case they are mathematical...
    Keep on going.

  • @mrbriadis
    @mrbriadis 3 роки тому

    what tools do you use to create this videos? How do you make sure we can track your 'pencil' ? I'd love to use this for my online teaching. Thanks for sharing these videos btw! learned a lot from them

  • @mentld
    @mentld 12 років тому

    Thank you! This helps me so much :) The videos themselves are great but would it be possible for the episodes to be number-ordered or could quotes and such be linked to previous episodes? UA-cam doesnt show videos in correct order.. Anyways thanks so much and sorry for my english :D

  • @josephdamen620
    @josephdamen620 6 років тому +1

    You the man Khan

  • @elektronic
    @elektronic 15 років тому

    saved my life man, thanks a bunch.

  • @ullasrathodiitk5041
    @ullasrathodiitk5041 10 років тому +1

    its really great...

  • @MrMaarij
    @MrMaarij 11 років тому

    God bless you good sir...God bless you...

  • @Silhouette93
    @Silhouette93 14 років тому +1

    What your doing is setting up simultaneous equations then solving them. Earlier we were using matrices to solve simultaneous equations. Can one use matrices and the determinant to see whether these are linearly independent?

  • @SuperStar-ql5cs
    @SuperStar-ql5cs 4 роки тому

    The lecturer is of Bangladeshi origin just like one of the co-founders of You Tube. That is one of the reasons why he is so good.

  • @JetKMendoza
    @JetKMendoza 12 років тому

    Legend bro, keep up the awesome work! I think you should come teach at my university haha
    Definitely subscribed!

  • @lhyx1990
    @lhyx1990 13 років тому

    Every computer science student who wanna make awesome 3d games should definitely check this out. Best Linear Algebra tutorial ever!!!

  • @hardtunesbigvibes
    @hardtunesbigvibes 14 років тому

    thanks.great explaination

  • @evachao4890
    @evachao4890 2 роки тому

    基(basis)定義:
    1. 可張成 subspace S 的向量
    2. 線性獨立
    作用: 可以用 basis 中向量的線性組合表示 subspace 中的任意向量
    (是生成次空間的最小向量集)
    PS: subspace 的 basis 不是唯一

  • @GeekBoy03
    @GeekBoy03 12 років тому

    I wish there are links to previous and next video in a series

  • @elenaorins5284
    @elenaorins5284 5 років тому

    Because I cannot find a video, is there a video on extending a basis?
    Thanks a lot for the video by the way! My college hates using matrices

  • @Maibes
    @Maibes 13 років тому

    this guy rocks my world

  • @denett01
    @denett01 11 років тому +1

    There is a linear algebra playlist with all the videos in order on his channel. This video is number 20.

  • @debasishkalita3962
    @debasishkalita3962 7 років тому

    you are great sir, when you say about the last video,can you provide the link as well sir?

  • @oluwatoba11
    @oluwatoba11 13 років тому +2

    "In a Basis, you have no redundancy!"

  • @pubududarshana4883
    @pubududarshana4883 Рік тому

    Thank You. You are great.

  • @irombebekanandameetei925
    @irombebekanandameetei925 5 років тому

    Definitely i love ur videos sir.

  • @DocMaple8
    @DocMaple8 14 років тому

    You, sir, are a godsend. And I'm not even religious. Thank you

  • @hadisyed1
    @hadisyed1 11 років тому

    I would gladly donate whatever amount you require to get the best tablet out there. So that you may continue to enrich our lives with your undeniable gift of teaching the most abstract and unwieldy concepts in the simplest manner.

  • @statushood
    @statushood 14 років тому

    great video!! thank you!

  • @KhoaNguyen-jn1vr
    @KhoaNguyen-jn1vr 11 місяців тому

    thanks for your lecture a lot

  • @hongly1318
    @hongly1318 11 років тому

    omg...you've saved my life.........!!

  • @crumcon
    @crumcon 15 років тому

    you know alot about math Khan

  • @JosephHarner
    @JosephHarner 11 років тому

    That would be entirely to effective, logical, and cost-efficient for any university to consider implementing.

  • @denebgarza
    @denebgarza 13 років тому

    @khanacademy for work, or not for work. I'd still learn this. It's interesting.

  • @janitarjanitar
    @janitarjanitar 14 років тому

    your the man Sal.

  • @Helping.aspirant
    @Helping.aspirant 5 років тому

    Thanks bery much

  • @kanishka475
    @kanishka475 10 років тому

    Thanks a lot.

  • @s4ms4r4
    @s4ms4r4 12 років тому

    Shame our world doesn't financially reward people who do such amazing work. Imagine, if he went to Goldmansachs making complex crazy market products he could make a lot more money!

  • @Incrue
    @Incrue 12 років тому

    Sal, you rock.There's a chance you make videos of electronics or mechatronics?
    Thank you very VERY much

  • @eda7210
    @eda7210 4 роки тому

    Thank you so much sir

  • @sickpee
    @sickpee 13 років тому

    Given a set of linearly dependent vectors, how would I determine which of those vectors I can "kick out" - so to speak - to get a basis for the space spanned by that set?

  • @Xlaxsauce
    @Xlaxsauce 14 років тому

    your the man Sal

  • @khalidteama2441
    @khalidteama2441 7 років тому

    Amazing.... thanks you very very much!!!!!

    • @khalidteama2441
      @khalidteama2441 7 років тому

      Everything makes perfect sense now... spent all day trying to understand my lesson until I came across this. Cant thank you enough!!

  • @onewashere
    @onewashere 12 років тому

    @TheGiglfoosm You have just described every one of my classes.

  • @dhruvbhati1347
    @dhruvbhati1347 3 роки тому +1

    Isn't it true that if we prove vectors v1 and v2 independent then it will automatically prove that they cover span R2, and vice versa? If so then we don't need to solve it 2 times

  • @damana1000
    @damana1000 10 років тому

    Thanks alot

  • @bobmuijs7401
    @bobmuijs7401 11 років тому

    You're a fraeakin' genius. I don't think I'm going to school anymore.

  • @vrchacho
    @vrchacho 13 років тому

    @norwayte Computer graphics won't have gotten anywhere without this.

  • @metalninjadragon
    @metalninjadragon 14 років тому

    These are awesome, especially for a grad student in controls (yes another one) who is suddently smacked in the face with algebra symbols he hasn't seen in 10 years.
    Why don't you mention the connection between linear independence and the determinent though?

  • @blockbusstar
    @blockbusstar 11 років тому +1

    Bill Gates give this man another million dollars !!! The ART OF EDUCATION !!!

  • @kyleblosser514
    @kyleblosser514 10 років тому

    @kingroy2377 basically, the vector is still in R^2 since it is a column vector with i and j components, thus making it two dimensional. The vector would be in R^3 if it were, for example, [2 3 1], since that has three components [i j k], rather than two components [i j], or [1 0] in this example

  • @Chriscx
    @Chriscx 10 років тому +18

    WHEN YOU SAY LAST VIDEO CAN YOU PLEASE PROVIDE A LINK TO THE LAST VIDEO!

    • @N1Kburchy
      @N1Kburchy 9 років тому +7

      If you go on their actual website it has them in order :)
      www.khanacademy.org/math/linear-algebra/vectors_and_spaces

    • @jiaqiwu4512
      @jiaqiwu4512 9 років тому +6

      if you view the playlist it also has them in order

  • @PwNStaaRR
    @PwNStaaRR 12 років тому

    Great video. Just a little confused on how to know if they are generating system of R^2 or R^3 and whether they are bases of R^2 or R^3?
    Can anyone answer please!

  • @MitzpatrickFitzsimmons
    @MitzpatrickFitzsimmons 12 років тому

    isnt it then possible to define subsets of vector coords to infinity to and or of the the eleventy-seventh?

  • @aniketpanda9302
    @aniketpanda9302 4 роки тому

    Sir can you please make a video on finite basis and infinite basis with examples(especially polynomials).

  • @kristkir
    @kristkir 12 років тому

    Great video, I feel like they should get rid of the useless lecturers and just play these videos in my algebra class.

  • @kam1am
    @kam1am 10 років тому

    This is awesome, I'd be screwed w/o this video

  • @catalinamaria9253
    @catalinamaria9253 11 років тому

    This Mr just saved my butt

  • @FileMaker_Consultant
    @FileMaker_Consultant 14 років тому

    Got a question. If you have a 3x4 matrix and after row-reducing there are 3 pivot columns, leaving behind one free variable. Will it be a basis for R3?