Rowspace and left nullspace | Matrix transformations | Linear Algebra | Khan Academy

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  • เผยแพร่เมื่อ 26 ม.ค. 2025

ความคิดเห็น • 25

  • @GeorgeNavarro
    @GeorgeNavarro 7 ปีที่แล้ว +11

    Thank you for this. My professor never actually taught us this and is putting it on the exam I am taking in an hour

  • @kevinmm20
    @kevinmm20 15 ปีที่แล้ว +9

    What a great explaination! See, you understand this and were able to explain this perfectly. Now that I understand it, this stuff isn't that difficult. So why is it that some text books and teachers like to make it difficult!?

  • @debendragurung3033
    @debendragurung3033 7 ปีที่แล้ว +10

    17:51; so that's the actual reason for the term LEFTNULLSPACE

    • @Nishchay-fk5lr
      @Nishchay-fk5lr 11 หลายเดือนก่อน

      g strang teaches a bit hazy

  • @gustavovbarroso
    @gustavovbarroso 10 ปีที่แล้ว +3

    Much needed review, just in time. Great vid!

  • @lemyul
    @lemyul 4 ปีที่แล้ว +2

    I wish I understand the book as much as I understand watching this video.

    • @lutherhoward7637
      @lutherhoward7637 3 ปีที่แล้ว

      Because you are not concentrating when you read. Reading math and physics books takes total concentration and reading sections more than once. Then, writing the concepts in your own words. Or teach it to someone. Lincoln studied by reading out loud.

  • @mky3405
    @mky3405 8 ปีที่แล้ว

    At 14:45, does Sal mean "column space of the R transpose matrix"?
    if not, what is "column span"?
    He sometimes says "column span", and it confused me.

  • @HotPepperLala
    @HotPepperLala 13 ปีที่แล้ว +2

    As much I as thank you for this video, you really didn't need to extend this for 23 mins, especially when the first 8 minutes is just review and you could have prepared the rref(M) ahead of time. I miss your straightforward videos in the past.

  • @davidsalcido1257
    @davidsalcido1257 11 ปีที่แล้ว

    Good job teaching..!

  • @fuahuahuatime5196
    @fuahuahuatime5196 11 ปีที่แล้ว +1

    Hey I have a question. How can you find the zero vector of a basis U with respect to the standard basis E?

    • @tis_i_sana
      @tis_i_sana 2 ปีที่แล้ว

      hm interesting question

  • @Rovshenification
    @Rovshenification 9 ปีที่แล้ว

    Thank you for this video.
    But I have a one question.
    We can determine the basis by number of vectors in our Matrix, right? For ex., we have three vectors (column) in matrix, thus dimension should be 3D space, yes?

    • @Postermaestro
      @Postermaestro 8 ปีที่แล้ว

      +Rovshen A-ev
      You can determine the basis of the column space of a matrix by counting the number of pivot entries in our reduced row echelon form of the matrix. If you have 3 pivot entries in your rref-matrix, that means that you have 3 linearly independent column vectors in your matrix. Thus, the dimension of the column space of the matrix is 3, or in other terms: the rank of the matrix is 3.

  • @parnashish1910
    @parnashish1910 3 ปีที่แล้ว

    Beautiful :)

  • @sanjaykrish8719
    @sanjaykrish8719 8 ปีที่แล้ว

    U are my God..

  • @Philips85281
    @Philips85281 12 ปีที่แล้ว +1

    Why you always choose simple matrix which simplified only 1 row left????

  • @ionglacier
    @ionglacier 15 ปีที่แล้ว

    crap dammit! why can't you be my proffesor???

    • @msaleem9704
      @msaleem9704 3 หลายเดือนก่อน

      he can't

  • @dupham7900
    @dupham7900 8 ปีที่แล้ว +1

    why name the video rowspace and left null space ? and then go on to explain column space, and barely anything about rowsapce

    • @QuickishFM
      @QuickishFM 6 ปีที่แล้ว +2

      because the rowspace is just the column space of the transposed matrix of A. You just find the column space again for the transposed matrix, which is the row space for the original non-transposed matrix

  • @malharjajoo7393
    @malharjajoo7393 8 ปีที่แล้ว

    explanation is not helpful

    • @msaleem9704
      @msaleem9704 3 หลายเดือนก่อน

      whyy ?