Basis and Dimension

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  • Опубліковано 23 кві 2019
  • 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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КОМЕНТАРІ • 151

  • @ChocolateMilkCultLeader
    @ChocolateMilkCultLeader 4 роки тому +497

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      @barrettjamie1642 2 роки тому +3

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    • @finnegandylan800
      @finnegandylan800 2 роки тому

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      @barrettjamie1642 2 роки тому

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    • @barrettjamie1642
      @barrettjamie1642 2 роки тому +4

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    • @finnegandylan800
      @finnegandylan800 2 роки тому +2

      @Barrett Jamie Happy to help :)

  • @quantumleap7964
    @quantumleap7964 Рік тому +13

    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

  • @christycaroline3697
    @christycaroline3697 3 роки тому +55

    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.

  • @perspicacity89
    @perspicacity89 Рік тому +5

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  • @user-pe1we2jp3j
    @user-pe1we2jp3j 3 роки тому +5

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  • @mmbpaja2190
    @mmbpaja2190 3 роки тому +6

    Thank you for explaining this topic so clearly. 💕

  • @margaretnmaju1982
    @margaretnmaju1982 Рік тому +2

    Professor Dave has really helped me and still helping me

  • @michaelpisciarino5348
    @michaelpisciarino5348 5 років тому +212

    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

  • @michaeltheisen
    @michaeltheisen 2 роки тому +3

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

  • @erikross-rnnow5517
    @erikross-rnnow5517 2 роки тому +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! :))

  • @immortalspiritualbeing7037
    @immortalspiritualbeing7037 Рік тому +3

    very clear explanation and examples,thank you !

  • @jingyiwang5113
    @jingyiwang5113 Рік тому +1

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

  • @hemanthkotagiri8865
    @hemanthkotagiri8865 5 років тому +21

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

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  5 років тому +33

      tell your friends and help me get there!

    • @hemanthkotagiri8865
      @hemanthkotagiri8865 5 років тому +8

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

    • @davidmulit8167
      @davidmulit8167 3 роки тому +12

      @@ProfessorDaveExplains This aged well.

    • @sandeepjabez
      @sandeepjabez 2 роки тому +2

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

    • @LexusKing-iz3up
      @LexusKing-iz3up Місяць тому +1

      3 now lol

  • @nikitabhatt5246
    @nikitabhatt5246 3 роки тому +1

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

  • @sekharp3305
    @sekharp3305 2 роки тому +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.

  • @sushmareddy5129
    @sushmareddy5129 3 роки тому

    Very easy to understand..Thanks for the video🙏

  • @christinenalwoga6008
    @christinenalwoga6008 3 роки тому

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

  • @tidalfriction5301
    @tidalfriction5301 3 роки тому

    This was incredible and clear bro!!!

  • @md_hyena
    @md_hyena 5 років тому +3

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

  • @b.cmagwaza6365
    @b.cmagwaza6365 4 роки тому +50

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

    • @Chad-be3jm
      @Chad-be3jm 4 місяці тому +3

      how are you doing now bud ?

    • @creedbratton4950
      @creedbratton4950 2 місяці тому

      I wanna know too ​@@Chad-be3jm

  • @nihaalsinghbhogal4837
    @nihaalsinghbhogal4837 2 роки тому

    Thanks Professor Dave! ❤

  • @meghanakrishna6190
    @meghanakrishna6190 Рік тому

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

  • @anandbhamashetti9730
    @anandbhamashetti9730 Місяць тому

    Great video. Very clear. With gratitude from india

  • @tenex0630
    @tenex0630 5 років тому +1

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

  • @leonardoguzman7854
    @leonardoguzman7854 Рік тому +1

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

  • @dter706
    @dter706 3 роки тому +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 роки тому +2

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

  • @danah81
    @danah81 8 місяців тому

    YOU ARE SAVING MINE AND MY ROMMAMTES FUTURES THX

  • @parasuramang1860
    @parasuramang1860 5 років тому +5

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

  • @ilong4rennes
    @ilong4rennes Рік тому

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

  • @Abdulrahman-hb6fy
    @Abdulrahman-hb6fy 2 місяці тому +1

    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

  • @farukakan8465
    @farukakan8465 3 роки тому

    Good expression , thanks 🇹🇷

  • @subhrasarkar3155
    @subhrasarkar3155 4 роки тому +1

    Thanks

  • @amitmishra-fe6yi
    @amitmishra-fe6yi 3 роки тому

    Really very good contain 🙏🏽

  • @anthonyfaddul3582
    @anthonyfaddul3582 6 місяців тому +1

    this guy is actually the goat

  • @olgachervonyuk4993
    @olgachervonyuk4993 11 місяців тому

    Wonderful theme

  • @kmishy
    @kmishy 3 роки тому

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

  • @fredhasopinions
    @fredhasopinions 3 роки тому

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

  • @bryananthonyangouw4045
    @bryananthonyangouw4045 2 роки тому

    so good
    thank you

  • @thesoccer10ful
    @thesoccer10ful 3 роки тому +4

    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 роки тому +1

      that was what i was thinking too :)

  • @tamizhazhagan-jaishreekris2199
    @tamizhazhagan-jaishreekris2199 5 років тому +1

    Superb 😃😃

  • @Soyokaze-if7kp
    @Soyokaze-if7kp 25 днів тому

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

  • @bernab
    @bernab 4 роки тому +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?

  • @flamesage6796
    @flamesage6796 Рік тому

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

  • @Mark-nh2vh
    @Mark-nh2vh 6 місяців тому +1

    Dave single handedly educated half a million people in 10 minutes

  • @user-tl6ry9kv8d
    @user-tl6ry9kv8d 5 років тому +1

    Thx

  • @ditya3548
    @ditya3548 2 роки тому

    thanks a lot!

  • @user-ih7iq6bw5o
    @user-ih7iq6bw5o 2 роки тому

    You are a godsend

  • @aleksanderaksenov1363
    @aleksanderaksenov1363 3 роки тому

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

  • @dddhhj8709
    @dddhhj8709 2 роки тому

    superb ....

  • @advancedappliedandpuremath
    @advancedappliedandpuremath Місяць тому

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

  • @samueltoluwani8405
    @samueltoluwani8405 3 роки тому +1

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

  • @iced751
    @iced751 2 роки тому +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 Рік тому

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

  • @ummehabiba7430
    @ummehabiba7430 3 роки тому

    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?

  • @yourmathtutor5130
    @yourmathtutor5130 3 роки тому +1

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

  • @anshedits2167
    @anshedits2167 8 місяців тому

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

  • @rahulsreedharan1922
    @rahulsreedharan1922 3 роки тому

    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 роки тому +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 роки тому +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)

  • @Starkeweg
    @Starkeweg Рік тому

    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

  • @mikakk2330
    @mikakk2330 4 роки тому +50

    why do professors make everything seem harder...?

    • @muhammadzaid308
      @muhammadzaid308 3 роки тому +1

      I wish I knew....

    • @joeysmith5767
      @joeysmith5767 3 роки тому +12

      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 роки тому +5

      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 роки тому +1

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

    • @swavekbu4959
      @swavekbu4959 2 роки тому +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.

  • @jellyfrancis
    @jellyfrancis 2 роки тому

    How to apply curl to higher dimensional vector field

  • @BlueLily-kx7mz
    @BlueLily-kx7mz Рік тому

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

  • @95yahel
    @95yahel 2 роки тому +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 роки тому +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.

  • @terekafaw9463
    @terekafaw9463 Рік тому

    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

  • @warfyaa6143
    @warfyaa6143 5 років тому +1

    cool haircut and nice video .

  • @swagatggautam6630
    @swagatggautam6630 Рік тому +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 Рік тому

      I thought the same thing, but idk

  • @kontiimanalatit8987
    @kontiimanalatit8987 10 місяців тому

    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 10 місяців тому

      I agree with this.

    • @nark4837
      @nark4837 6 місяців тому

      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

  • @tamannashaikh2712
    @tamannashaikh2712 3 місяці тому

    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 3 місяці тому

      works either way, i think

    • @karthi6548
      @karthi6548 3 місяці тому

      because all we aim is to reduce the variables

  • @theojunming
    @theojunming Рік тому

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

  • @AS-ds4in
    @AS-ds4in 2 роки тому

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

    • @AS-ds4in
      @AS-ds4in Рік тому +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

  • @codeworld420
    @codeworld420 Рік тому

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

  • @RohitKumar-zp6ci
    @RohitKumar-zp6ci Рік тому

    Can anyone provide me solution of last 2 questions?

  • @Christian-mn8dh
    @Christian-mn8dh Рік тому

    4:54

  • @azammozaffarikhah26
    @azammozaffarikhah26 Рік тому

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

  • @kotikunja7583
    @kotikunja7583 3 роки тому

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

  • @tomatrix7525
    @tomatrix7525 2 роки тому +1

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

  • @momenabubasha7060
    @momenabubasha7060 Рік тому

    why is the first one not a basis in the comprehension

  • @ToanPham-wr7xe
    @ToanPham-wr7xe 5 місяців тому

    😮

  • @ultimateboss5161
    @ultimateboss5161 Місяць тому

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

  • @topiado2073
    @topiado2073 4 роки тому +1

    Sir ua so handsome

  • @maxingout6124
    @maxingout6124 Рік тому

    He unlocked the 4th dimension 👀

  • @zilunhe8191
    @zilunhe8191 Рік тому

    Save my life

  • @jestinaluvanda-jm4tc
    @jestinaluvanda-jm4tc Рік тому

    Move words passing through a video when you are explaining

  • @rossfriedman6570
    @rossfriedman6570 8 місяців тому

    Sahh dude

  • @ethiopiandishtechnotian
    @ethiopiandishtechnotian 2 роки тому

    Pls help me?

  • @patrick-zb6fx
    @patrick-zb6fx 2 роки тому

    thank you linear algebra jesus.

  • @OP-yw3ws
    @OP-yw3ws 2 роки тому

    why aren't u my college professor 😭

  • @GoogleUser-nx3wp
    @GoogleUser-nx3wp 2 роки тому

    What happend to your hair prof ?

  • @justthenamekevin
    @justthenamekevin 2 роки тому

    in french: span is engendré!!!

  • @is6815
    @is6815 5 років тому +1

    1st to comment!

  • @FootLettuce
    @FootLettuce 3 роки тому

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

  • @siddharthkumar4440
    @siddharthkumar4440 11 місяців тому

    I miss the jesus version 😂😂

  • @lakshaysharma2116
    @lakshaysharma2116 Рік тому

    There is god and he is an American

  • @honestdudeguru
    @honestdudeguru 2 роки тому

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

  • @cho.gath789
    @cho.gath789 4 роки тому +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 роки тому +43

      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 3 роки тому +17

      The pacing is all good to me

    • @farhatfatima1168
      @farhatfatima1168 2 роки тому

      @@ProfessorDaveExplains yes you are right sir