Basis and Dimension

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  • Опубликовано: 13 окт 2024
  • Now we know about vector spaces, so it's time to learn how to form something called a basis for that vector space. This is a set of linearly independent vectors that can be used as building blocks to make any other vector in the space. Let's take a closer look at this, as well as the dimension of a vector space, and what that means.
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Комментарии • 158

  • @quantumleap7964
    @quantumleap7964 Год назад +17

    wow, these last couple of videos of the playlist help make a complete comprehensive overview of the ideas need to learn tensor algebra and tensor calculus. This is a must watch for any General Relativity student

  • @michaelpisciarino5348
    @michaelpisciarino5348 5 лет назад +217

    0:27 A Basis
    1:31 Check Linear Combination
    2:26 Span
    2:52 Satisfying Linear Independence
    3:21 A more complicated example (R 2x2)
    3:54 Span check
    4:23 Distribute the Scalars. Add up the new matrix.
    4:45 Make sure a solution exists
    5:43 Check Linear Independence
    6:57 Row Echelon Form:
    - No Free Variables
    - All Scalars must be = 0
    7:34 Both conditions verified ✔️
    Basis With N Elements= Dimension N
    9:05 Check Comprehension

  • @ChocolateMilkCultLeader
    @ChocolateMilkCultLeader 4 года назад +548

    One day, I'll pay all the great tutors on RUclips back.

    • @barrettjamie1642
      @barrettjamie1642 3 года назад +3

      i know Im randomly asking but does anyone know a method to log back into an Instagram account..?
      I stupidly lost my account password. I appreciate any help you can offer me.

    • @finnegandylan800
      @finnegandylan800 3 года назад

      @Barrett Jamie Instablaster :)

    • @barrettjamie1642
      @barrettjamie1642 3 года назад

      @Finnegan Dylan i really appreciate your reply. I found the site through google and I'm trying it out atm.
      Looks like it's gonna take a while so I will reply here later with my results.

    • @barrettjamie1642
      @barrettjamie1642 3 года назад +4

      @Finnegan Dylan It worked and I finally got access to my account again. I am so happy!
      Thanks so much you saved my ass !

    • @finnegandylan800
      @finnegandylan800 3 года назад +2

      @Barrett Jamie Happy to help :)

  • @christycaroline3697
    @christycaroline3697 3 года назад +59

    The way you explain is wonderful. I'm glad I found you. I was breaking my head with these concepts, now it's all clear. Thanks a million for making it EASY. :) God bless.

  • @thomasezequielfisher9161
    @thomasezequielfisher9161 2 месяца назад +1

    Your videos are great, very easy to understand, clear voice and good visuals . The only recommendation that I'd give you is to show the process of the comprehension check problems. Keep up the good work

  • @Abdulrahman-hb6fy
    @Abdulrahman-hb6fy 6 месяцев назад +5

    I have a sweet information
    When n (number of columns) is not equal to m (number of rows) then the set is always not a basis (if the question ask if a specific set of vectors is a basis or not)
    but when n = m, then you have two possibilities depending on the det(A), in other words:
    det(A) is equal to 0 ==> the set is not a basis
    det(A) isn't equal to 0 ==> the set is a basis

  • @hemanthkotagiri8865
    @hemanthkotagiri8865 5 лет назад +22

    I love your content. Why don't you have a million subs yet man!?

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  5 лет назад +34

      tell your friends and help me get there!

    • @hemanthkotagiri8865
      @hemanthkotagiri8865 5 лет назад +9

      @@ProfessorDaveExplains I'm already on it, Dave.

    • @davidmulit8167
      @davidmulit8167 3 года назад +11

      @@ProfessorDaveExplains This aged well.

    • @sandeepjabez
      @sandeepjabez 2 года назад +2

      @@ProfessorDaveExplains well, look where you are!!
      btw, is there a way I can get hold of your presentation 'ppt'?

    • @LexusKing-iz3up
      @LexusKing-iz3up 4 месяца назад +1

      3 now lol

  • @margaretnmaju1982
    @margaretnmaju1982 Год назад +2

    Professor Dave has really helped me and still helping me

  • @perspicacity89
    @perspicacity89 2 года назад +5

    Wow! Thank you so much! Your videos are so simple, easy to understand, and concise! Thank you!

  • @AbigailAranovich
    @AbigailAranovich 3 года назад +5

    Wow u are an awesome tutor. I easily learned the topics in 1 hour instead of 24 hours of nonsense thank u so much😊😊😊😊

  • @mmbpaja2190
    @mmbpaja2190 3 года назад +6

    Thank you for explaining this topic so clearly. 💕

  • @dter706
    @dter706 3 года назад +3

    The reduced row echelon form isn't finished yet at 7:22, you can still do R3+R4, R2-R4 and after that R1-R3 which doesn't require you to solve the remaining set of equations.

    • @johanjimenez1249
      @johanjimenez1249 3 года назад +2

      You don't need to since you can see c4 is equal to zero which would then make the rest zero.

  • @erikross-rnnow5517
    @erikross-rnnow5517 2 года назад +8

    Basis vectors/Matrices seemed so far out of reach even after trying to understand them for a couple of weeks but after this video, which make them seem easy, I think I finally understand them. Thanks Dave! :))

  • @michaeltheisen
    @michaeltheisen 2 года назад +3

    Thank you for explaining this so straight forward and to the point.

  • @immortalspiritualbeing7037
    @immortalspiritualbeing7037 2 года назад +3

    very clear explanation and examples,thank you !

  • @parasuramang1860
    @parasuramang1860 5 лет назад +5

    Please send reference books, websites that you use... That would be helpful.

  • @anandbhamashetti9730
    @anandbhamashetti9730 5 месяцев назад

    Great video. Very clear. With gratitude from india

  • @b.cmagwaza6365
    @b.cmagwaza6365 5 лет назад +56

    you saved my life, linear algebra wanted me not to graduate

    • @Chad-be3jm
      @Chad-be3jm 7 месяцев назад +4

      how are you doing now bud ?

    • @creedbratton4950
      @creedbratton4950 5 месяцев назад

      I wanna know too ​@@Chad-be3jm

  • @sekharp3305
    @sekharp3305 2 года назад +1

    Thanks a lot for sharing your knowledge. Your explanation is good. It would have been better if you have included explanation of the question and answers also.

  • @anthonyfaddul3582
    @anthonyfaddul3582 10 месяцев назад +1

    this guy is actually the goat

  • @jingyiwang5113
    @jingyiwang5113 Год назад +1

    Your video is amazing! I finally understand this point. Thank you so much!

  • @nikitabhatt5246
    @nikitabhatt5246 4 года назад +1

    YOU ARE AMAZING! YOU NEED TO HAVE MORE SUBS!!

  • @thesoccer10ful
    @thesoccer10ful 3 года назад +6

    5:05 since you’re taking the determinate of the square matrix and it’s a none zero number, isn’t also linearly independent too?

    • @gayathrik8194
      @gayathrik8194 3 года назад +1

      that was what i was thinking too :)

    • @user-ih7iq6bw5o
      @user-ih7iq6bw5o Месяц назад

      Yes. A nonzero determinant of the matrix of column vectors immediately indicates a basis.
      www.yorksj.ac.uk/media/content-assets/study-skills/maths-and-statistics/linear-algebra/Finding-a-Basis-Quickguide.pdf

  • @Mark-nh2vh
    @Mark-nh2vh 9 месяцев назад +1

    Dave single handedly educated half a million people in 10 minutes

  • @bernab
    @bernab 5 лет назад +3

    I think the first 3 vectors is because for a R2, one need only 2 vectors for creating a base for R2. Plus, 3,2 could be 2 times the 1,0. Right?

    • @CHEESYhairyGASH
      @CHEESYhairyGASH 2 года назад

      Yeah, the could be built using 2 x + 1 x

  • @leonardoguzman7854
    @leonardoguzman7854 Год назад +1

    I literally understood something that my professor has been explaining for two weeks in just 10 minutes. Thanks!

  • @danah81
    @danah81 11 месяцев назад

    YOU ARE SAVING MINE AND MY ROMMAMTES FUTURES THX

  • @Soyokaze-if7kp
    @Soyokaze-if7kp 4 месяца назад

    I already gave a like as soon as I saw the intro

  • @md_hyena
    @md_hyena 5 лет назад +3

    Thank You! Can't wait for a video about a uniform space and tensors; I repent, I never truly understood them.

  • @ilong4rennes
    @ilong4rennes Год назад

    tysm!!!!!! you saved my life!!

  • @terekafaw9463
    @terekafaw9463 Год назад

    1. The dimension of the matrix is
    2. In the matrix , the entry in the third row and second column is _____.
    3. For what values of and , the two matrices are equal?______
    4. Write a diagonal matrix of order two, such that the entries on the diagonal zero._______
    5. Given the following matrices and , then compute
    a) b) c) d) e) f)
    6. Find the products of a row matrix and the column matrix ; that is and YX.
    7. A manufacturer produces three products: A, B, and C, which he can sell in two markets. Annual sales volume is indicted as follows.
    Product A B C
    Market I 10,000 units 2,000 units 80,000 units
    Market II 6,000 units 20,000 units 8,000 units
    a) If unit sales of A, B, and C are 2.50 Birr, 1.25 Birr, and 1.50 Birr, respectively, find the total revenue as a product of matrices in each market.
    b) If unit sales of A, B, and C are 1.80 Birr, 1.20 Birr, and 0.80 Birr, respectively, find the gross profit as a product of matrices in each market
    pleas do you make this

  • @christinenalwoga6008
    @christinenalwoga6008 3 года назад

    I never imagined that I would ever understand linear algebra. Thanks bro

  • @happyfrogkhmel
    @happyfrogkhmel Год назад

    Wonderful theme

  • @gaurishagrawal9404
    @gaurishagrawal9404 27 дней назад

    at 4:11, how does it span the vector space? What if I want the vector [1 2; 2 0]. How would you get that using the given vectors?

  • @sushmareddy5129
    @sushmareddy5129 4 года назад

    Very easy to understand..Thanks for the video🙏

  • @subhrasarkar3155
    @subhrasarkar3155 4 года назад +1

    Thanks

  • @meghanakrishna6190
    @meghanakrishna6190 Год назад

    these r so helpful and great !! helping me survive thru college 😄😁

  • @aleksanderaksenov1363
    @aleksanderaksenov1363 3 года назад

    but the main question is-why the canonical basis is indexed by natural numbers?And can we describe canonaical basis in terms of matrices?

  • @fredhasopinions
    @fredhasopinions 3 года назад

    sir, you're a hero, jesus christ you have no idea how doomed i'd be without this video right now

  • @rahulsreedharan1922
    @rahulsreedharan1922 4 года назад

    If they are linearly independent, it means there are no linear combinations among the vectors. So, how can a basis have two conditions where (1) they are linearly independent and (2) they span the vector space V (by a linear combination of the vectors), don't the conditions contradict each other? Please clarify, and let me know if I'm missing something here.

    • @sahilkhurana6941
      @sahilkhurana6941 3 года назад +1

      Dude ! Linearly independent does not mean that they will have no linear combination its actually satisfies that they can have linear combination coz we check that the vectors are not dependant so that we can have all the possible linear combination!

    • @RahulSharma-oc2qd
      @RahulSharma-oc2qd 3 года назад +2

      Linear combination and linear dependent is two different things. Whether given two vector elements within the vector space are linearly dependent or not has to do nothing with the linear combination. Any set of vector elements can be written as linear combination (with respect to their coefficients)

  • @swagatggautam6630
    @swagatggautam6630 Год назад +1

    For R 2X2 matix, can't we just say that the matices are linearly independent as their determinant is not equal to zero.
    We created the matrix 4X4 which is a square matrix and its determinant is 1, so it satisfies that they are linearly independent.!!!

    • @Anton-vy5dt
      @Anton-vy5dt Год назад

      I thought the same thing, but idk

  • @iced751
    @iced751 2 года назад +1

    At 5:26 how is the determinant 1? Cause multiplying the 4 brackets above from the formula (ad-bc) gets: 0, 0, 1, then the last one is 0-1 which is -1

    • @egeyesilyurt3701
      @egeyesilyurt3701 Год назад

      doesnt matter regardless, if the det isnt equal to 0 we can proceed

  • @nihaalsinghbhogal4837
    @nihaalsinghbhogal4837 2 года назад

    Thanks Professor Dave! ❤

  • @tidalfriction5301
    @tidalfriction5301 3 года назад

    This was incredible and clear bro!!!

  • @tenex0630
    @tenex0630 5 лет назад +1

    Thanks for teaching me Newton's Laws!
    ~We love your work

  • @95yahel
    @95yahel 2 года назад +1

    How can you have more than a dimension of 3 in a 3D space? Wouldnt any more vectors are just repetitive and therefore be linearly dependent?

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  2 года назад +2

      Mathematics isn't limited to the three spatial dimensions we are familiar with, it can utilize many more. We just are incapable of visualizing it.

  • @samueltoluwani8405
    @samueltoluwani8405 3 года назад +1

    For the first question in the comprehension part, 0 is the determinant, so that should be linearly dependent right?

    • @eduardomoreira7624
      @eduardomoreira7624 3 года назад

      Independent

    • @eduardomoreira7624
      @eduardomoreira7624 3 года назад

      |A|=0 =linearly independent

    • @user-ih7iq6bw5o
      @user-ih7iq6bw5o Месяц назад

      @@eduardomoreira7624 This is not true. A determinant of 0 means that the columns of the matrix are linearly dependent.

  • @advancedappliedandpuremath
    @advancedappliedandpuremath 4 месяца назад

    Sir can we find the null space of set of vectors from M2x2 like we do for vectors in R^n

  • @farukakan8465
    @farukakan8465 3 года назад

    Good expression , thanks 🇹🇷

  • @bryananthonyangouw4045
    @bryananthonyangouw4045 3 года назад

    so good
    thank you

  • @mikakk2330
    @mikakk2330 4 года назад +55

    why do professors make everything seem harder...?

    • @muhammadzaid308
      @muhammadzaid308 3 года назад +1

      I wish I knew....

    • @joeysmith5767
      @joeysmith5767 3 года назад +13

      They feel like they have to fill up the lecture time that was assigned and they end up stretching the material out in a complex way to fill the time

    • @gemy6188
      @gemy6188 3 года назад +6

      It's about Talent and the different criteria, some have the knowledge but they haven't the capability to deliver this knowledge.

    • @kmishy
      @kmishy 3 года назад +1

      @@gemy6188 In India we could also talk about lack of knowledge and poor delivery skills

    • @swavekbu4959
      @swavekbu4959 3 года назад +3

      Two reasons: 1. They don't know how to teach and don't have a firm grasp of the subject themselves. 2. They want to confuse you so that fewer people have mastery of the knowledge. The less you know, the more they know, and people with big egos want to have "specialized" knowledge that is not accessible to others. Write a book nobody understands, and claim yourself a genius.

  • @flamesage6796
    @flamesage6796 Год назад

    Do free variables effect whether or not the basi can be linearly independent?

  • @ummehabiba7430
    @ummehabiba7430 3 года назад

    Linear independent vectors means we cant take linear combination of them...on the other hand span is all the linear combination of those vectors. Basis is the vectors will be linearly independent + they will span. I am confused...how these 2 can be true at the same time?

  • @Richard___554o
    @Richard___554o 3 месяца назад

    Hello, I have some delightful news that will brighten your day!

  • @kmishy
    @kmishy 3 года назад

    Can we expect a subspace who span vector space but vectors (elements ) in that subspace are linearly dependent?

  • @yourmathtutor5130
    @yourmathtutor5130 3 года назад +1

    What if such cases when determinant is zero yet it has infinitely many solutions?

  • @kontiimanalatit8987
    @kontiimanalatit8987 Год назад

    Doesn't the det of matrix being 1 (not 0) means its elements are linearly independent (so we don't need to form row echelon form)

    • @Yuu.riishii
      @Yuu.riishii Год назад

      I agree with this.

    • @nark4837
      @nark4837 10 месяцев назад

      also, can you confirm that there is no point in ever checking both conditions for basis, i.e., condition 1: spanning, condition 2: linearly independent?
      if you know it spans and number of vectors > number of dimensions, it can't be a basis.
      if you know it spans and number of vectors = number of dimensions, it MUST be a basis.
      if you know number of vectors < number of dimensions, it can't span?
      you might as well just manually look, saves you work

  • @dddhhj8709
    @dddhhj8709 2 года назад

    superb ....

  • @tamizhazhagan-jaishreekris2199
    @tamizhazhagan-jaishreekris2199 5 лет назад +1

    Superb 😃😃

  • @y18-s8j
    @y18-s8j 5 лет назад +1

    Thx

  • @ditya3548
    @ditya3548 3 года назад

    thanks a lot!

  • @ShaunOReilly-h3u
    @ShaunOReilly-h3u 12 дней назад +1

    really great video prof.Dave! #bakasenpai

  • @srikanthv-sw4zn
    @srikanthv-sw4zn 2 месяца назад

    why didnt u use the other possible diagonal as the last element at 3:52

  • @amitmishra-fe6yi
    @amitmishra-fe6yi 3 года назад

    Really very good contain 🙏🏽

  • @kotikunja7583
    @kotikunja7583 3 года назад

    Professor, vector space with the only vector "zero vector" has dimension 1. 8:23

  • @jellyfrancis
    @jellyfrancis 2 года назад

    How to apply curl to higher dimensional vector field

  • @Starkeweg
    @Starkeweg Год назад

    what if instead of all leading ones we had a leading 2 in some position. thats okay right ?. since its not Reduced row echelon form

  • @anshedits2167
    @anshedits2167 Год назад

    2 v + 3 w.. In this v and w are vectors and these are basis as well?

  • @BlueLily-kx7mz
    @BlueLily-kx7mz Год назад

    But Im not getting the determinant value as 1 in example 2 while checking for spaning 5.23 ...
    Can somebody please help.... please...

  • @tamannashaikh2712
    @tamannashaikh2712 6 месяцев назад

    Can somebody please help me? In the previous video where we had to check whether a matrix is linear independent or not by row operation, we didn't get all 1's in the main diagonal. But in this video why do I have to get all one's in the main diagonal?

    • @karthi6548
      @karthi6548 6 месяцев назад

      works either way, i think

    • @karthi6548
      @karthi6548 6 месяцев назад

      because all we aim is to reduce the variables

  • @theojunming
    @theojunming 2 года назад

    Isnt the set of vectors rank 4 ? How can a rank 4 span R2

  • @codeworld420
    @codeworld420 Год назад

    in the comprehension, how the first one is not linearly independent ?

  • @warfyaa6143
    @warfyaa6143 5 лет назад +1

    cool haircut and nice video .

  • @tomatrix7525
    @tomatrix7525 2 года назад +1

    This is a godsend. Ya boy thought he was fucked for midterm

  • @AS-ds4in
    @AS-ds4in 2 года назад

    6:36
    how can we multiply R3 by -1
    wont it change the equation??

    • @AS-ds4in
      @AS-ds4in Год назад +2

      Found this comment 6 months later and now i know the answer
      if we multiply both sides of an equation it will still remain the same equation and is valid
      here the other side of the equation(right of =) is 0 and 0 multiplied by anything gives 0 so we dont include it

  • @azammozaffarikhah26
    @azammozaffarikhah26 Год назад

    thank you, can you give me a vector space with infinite dimensions?

  • @momenabubasha7060
    @momenabubasha7060 2 года назад

    why is the first one not a basis in the comprehension

  • @ultimateboss5161
    @ultimateboss5161 5 месяцев назад

    Your explanation is good but you didnt explain the type of questions in the check comprehension

  • @maxingout6124
    @maxingout6124 Год назад

    He unlocked the 4th dimension 👀

  • @Christian-mn8dh
    @Christian-mn8dh 2 года назад

    4:54

  • @RohitKumar-zp6ci
    @RohitKumar-zp6ci Год назад

    Can anyone provide me solution of last 2 questions?

  • @jestinaluvanda-jm4tc
    @jestinaluvanda-jm4tc Год назад

    Move words passing through a video when you are explaining

  • @patrick-zb6fx
    @patrick-zb6fx 2 года назад

    thank you linear algebra jesus.

  • @zilunhe8191
    @zilunhe8191 Год назад

    Save my life

  • @ToanPham-wr7xe
    @ToanPham-wr7xe 8 месяцев назад

    😮

  • @OP-yw3ws
    @OP-yw3ws 2 года назад

    why aren't u my college professor 😭

  • @rossfriedman6570
    @rossfriedman6570 Год назад

    Sahh dude

  • @FootLettuce
    @FootLettuce 3 года назад

    Stop watching anime brother.
    We must fight the MPLA.
    (Matrices Projections Linear Algebra)

  • @GoogleUser-nx3wp
    @GoogleUser-nx3wp 2 года назад

    What happend to your hair prof ?

  • @topiado2073
    @topiado2073 4 года назад +1

    Sir ua so handsome

  • @ethiopiandishtechnotian
    @ethiopiandishtechnotian 3 года назад

    Pls help me?

  • @justthenamekevin
    @justthenamekevin 2 года назад

    in french: span is engendré!!!

  • @sojulia1990
    @sojulia1990 5 лет назад +1

    1st to comment!

  • @siddharthkumar4440
    @siddharthkumar4440 Год назад

    I miss the jesus version 😂😂

  • @lakshaysharma2116
    @lakshaysharma2116 2 года назад

    There is god and he is an American

  • @honestdudeguru
    @honestdudeguru 3 года назад

    I am disappointed...I sent you an email two weeks ago. No response from you yet.

  • @cho.gath789
    @cho.gath789 4 года назад +1

    Dude... Every 5 seconds you pause for like 3 seconds.... then we all get to hear you take a deep breath and talk for 5 more seconds, then pause again. You need to just relax and talk like you are in a conversation.

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  4 года назад +42

      No. The pacing is deliberate for those who need time to process what's on the screen. Teaching math is not a conversation.

    • @aryanks2167
      @aryanks2167 4 года назад +17

      The pacing is all good to me

    • @farhatfatima1168
      @farhatfatima1168 2 года назад

      @@ProfessorDaveExplains yes you are right sir