Linear Algebra 6.5.1 Least Squares Problems

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  • Опубликовано: 17 янв 2025

Комментарии • 128

  • @aukusitinoah-yek99
    @aukusitinoah-yek99 4 года назад +63

    Thank you so much for doing this series! You really do deserve more credit. These videos have allowed me learn Linear Algebra throughout this quarantine!

  • @thezeneris
    @thezeneris 3 года назад +40

    I'm a 44 year old stay-at-home dad and a college junior. Your Linear Algebra and Discrete Math playlists have been a lifesaver. Thank you for all the good work you do and thank you for sharing it with us!

    • @wrestlingscience
      @wrestlingscience 2 года назад

      Are you studying computer science?

    • @thezeneris
      @thezeneris 2 года назад +2

      @@wrestlingscience I am a Data Science major.

    • @muhammadabdullahriazbhatti
      @muhammadabdullahriazbhatti Год назад +1

      @@thezeneris How's it going so far?

    • @thezeneris
      @thezeneris Год назад +2

      @@muhammadabdullahriazbhatti I only need 2 classes in the fall to finally get a degree. I've also had an internship and am looking forward to going back to work with my new skills. Thanks for asking and how are you?

    • @thezeneris
      @thezeneris Год назад +3

      @Akash S
      For my degree, we were required to study differential and integral calculus as well as multivariable calculus. Then there was linear algebra followed by advanced linear algebra with optimization. We also studied one semester of discrete math, probability and statistics, statistical inference, regression analysis and finally statistical and machine learning. There is also a fair amount of programming in computer science classes and data science classes and while they were not math classes, there was often math involved.

  • @jacksatcher8010
    @jacksatcher8010 Год назад +5

    Thank you so much for these videos. You have been a huge help to 31,000 people so far with many more to come. Youve certainly been one of the only reasons my grade and understanding of this course is where it is now and I can't thank you enough making this free for everyone.

  • @king069-xr3hm
    @king069-xr3hm 7 месяцев назад +5

    Thanks Kimberly! You are a great teacher I consider myself lucky to have found your RUclips channel.

  • @pietropecora1335
    @pietropecora1335 4 года назад +16

    coming in clutch hours before my final, i've been using your videos since youre discrete math videos. thank you!

    • @SawFinMath
      @SawFinMath  3 года назад +1

      Thanks for watching! Glad I could help!

  • @nickyggoodman
    @nickyggoodman Год назад +1

    Thank you! I have been coming to these videos whenever I have a hard time wrapping my head around what the book is saying. It's nice to have a replay of what we went over in lecture. Much help during my review :)).

  • @wrestlingscience
    @wrestlingscience 2 года назад +4

    You are the linear algebra youtube goat. You use simple language, pre-pare slides so we dont just sit there watching you write stuff, you show all work and speak clearly and explain reasoning without becoming too theoretical and abstract. Everything i wrote is what my professor does and makes learning from his videos so difficult. Thank you for teaching this way and for helping me

  • @brilliantstarss
    @brilliantstarss 2 года назад +3

    I just can't say how grateful I am, Kimberly! I loved your course from the beginning to the end. I loved your teaching and your subtle humor. It was such an amazing time. Thank you very much for this. I hope you can reach more people! You are the best! Keep on being amazing! Now, I'm going to your calculus and I am already confident that I will get so much knowledge!!!! Thank you so much! Stay blessed!

    • @pianodan1608
      @pianodan1608 2 года назад

      You did linear algebra before calculus ?!

  • @denaude7058
    @denaude7058 9 месяцев назад

    Thank you, Prof Brehm for explaining Linear Algebra so well. I've watched so many other youtubers, but you were the one that got through to me.
    Greetings from South Africa.

  • @angelasmith7894
    @angelasmith7894 4 года назад +8

    For the last practice problem at 16:35, I got a slightly different answer for step 4. I got -5 instead of 5. I'd show my row operations but it doesn't seem I'm able to put in a pic in comments and writing it out like I did below is too cumbersome. Hope this helps others.
    RREF:
    1 0 0 1 3
    0 1 0 -1 -5
    0 0 1 -1 -2
    0 0 0 0 0

    • @SawFinMath
      @SawFinMath  3 года назад +1

      Yes it should be -5. It's an error. Thank you for letting me know!

  • @Damdahlf
    @Damdahlf 2 года назад +5

    I usually don't leave comments on youtube videos, but I just wanted to thank you for these amazing videos. I was not a fan of how my college professor was teaching Linear Algebra, and my grades were suffering as a result. I quickly turned to youtube for help. Upon finding this playlist, I began skipping lecture and watching your videos instead. Let's just say I made the correct decision. I am currently sitting at a 93% in the class with only a final quiz, homework, and exam to go! Thank you so much!

    • @SawFinMath
      @SawFinMath  2 года назад

      Thanks so much for the kind words! Glad I could help!

  • @SebastianVargas-b6c
    @SebastianVargas-b6c 2 месяца назад

    Thank you so much, I've been looking so long for a video like this!

  • @ricardotrevizo7059
    @ricardotrevizo7059 Год назад

    You saved my college GPA! I'm definitely gonna show this playlist to all of my friends who are going to be doing linear algebra, thank you so much!

  • @throatgoat69420
    @throatgoat69420 4 месяца назад

    Hey I dont think I've ever commented on a youtube video but I feel like you really deserve it, I'm in college taking linear algebra and the lectures/textbook just over complicate everything. After watching your whole linear algebra series, I have never felt more confident taking the final today. Thank you for everything!

  • @ahmadabdullah262
    @ahmadabdullah262 3 года назад

    Thanks for the course. I recently just learned about the linear regression algorithm and its basically what you've been teaching in this last unit. Taking a vector and trying to split it in two orthogonal vectors

  • @angelasmith7894
    @angelasmith7894 4 года назад +5

    I love your videos! Just want to mention a minor error in your matrix transformation at the 6:00 min mark. In the first transformation you show that the 3rd row reduces to [0, -1, 0] when it should be [0, 1, 0]. The system is still inconsistent so the outcome is the same.
    1 1 2 1 1 2
    0 1 1 ~ 0 1 1
    1 2 2 0 1 0
    Thank you so much for your videos!

    • @SawFinMath
      @SawFinMath  3 года назад

      Thanks for letting me know!

  • @jayjani5427
    @jayjani5427 2 года назад

    You are actually amazing!! Thanks for all of your videos and help!!

  • @bloodyglitch1777
    @bloodyglitch1777 5 месяцев назад +1

    Watched every video in the playlist for my summer linear algebra class. The prerecorded college lectures were in 240p with a bad microphone. Thanks so much, you saved my butt in this class (and discrete math)

  • @shengtong6772
    @shengtong6772 4 года назад +3

    Report an error: at 16:19, the last element in the second row should be -5 rather than 5. Anyway, it's great!

    • @daniyelzhumankulov7733
      @daniyelzhumankulov7733 4 года назад +1

      The same thing. I redid it because of that.
      Confirm that it should be negative 5

    • @SawFinMath
      @SawFinMath  3 года назад

      Thanks for letting me know! Yes it should be -5.

  • @Sikoro_
    @Sikoro_ 3 года назад

    Dr. Brehm, THANK YOU so much for this video series! When I started this semester with the pandemic going on, I had no clue of what was going on in Linear Algebra since my professor made his lectures confusing and much more difficult than they needed to be. Fortunately my lectures followed the same six chapters that you covered in your course, so I was able to follow alongside with you! After studying and working hard on my HW, exams, and quizzes, taking notes from your videos, and going back when I got stuck, I'm happy to say I got an A in the course :) Again, thank you for posting this video series and I hope you continue to help many people by posting more math videos!

    • @SawFinMath
      @SawFinMath  3 года назад

      Thanks so much for taking the time to write this. So glad I was able to help!

  • @batuskovichuman6886
    @batuskovichuman6886 5 месяцев назад +1

    this is it guys.

  • @gillianmarlow404
    @gillianmarlow404 2 года назад

    Just passed my linear class with a very high A because of your videos. Thank you so much for what you do!

  • @jovantay521
    @jovantay521 Год назад

    These videos are amazing. We happen to be using the same textbook for our linear algebra course and your videos breakdown the concepts so well. tysm!

  • @kassymchurchman5511
    @kassymchurchman5511 Год назад

    this cousre in addition with series of vids “essence of linear algerbra” is really a key

  • @kaijogym
    @kaijogym Год назад

    Truly truly thank you Ms. Brehm for this playlist. You are such a great teacher. Hoping I do well on my final tomorrow!!

  • @saraf4782
    @saraf4782 2 года назад

    Thank you so much for making this series! Using it as a crash course before my exam!!

  • @Ryan-cx4ni
    @Ryan-cx4ni 2 года назад

    Thank you so much for making these videos. You helped me pass my linear algebra course!!

  • @jasperjansen1150
    @jasperjansen1150 Год назад

    I am a senior in college and needed to pass this course to set me up for a class in my final semester. Wasn't feeling confident in my abilities to score highly enough to get a good grade to earn credit. I watched all your videos and worked all the problems as you went through them within a 2 day period as I crammed for the final. I ended up not only passing the course but getting my highest exam score of the semester on the final. All thanks to you! Great series!

  • @Megajim454
    @Megajim454 3 года назад

    Thank you for all your clear explanations throughout this series!

  • @maryambibi2183
    @maryambibi2183 3 года назад

    THANK YOU SO MUCH FOR THESE VIDEOS.....trust me I learned a lot of things in linear algebra. I do have linear algebra course in my 3rd semester and was struggling with it. Thank god i got your videos. You deserve more than any likes or comments.... LOTS OF LOVE FROM A STUDENT ..

  • @DoggletPug
    @DoggletPug Год назад

    Thanks for all your hard work Prof!

  • @gabrielmena2723
    @gabrielmena2723 2 года назад

    Thank you so much for this series! You have no idea how helpful you've been for many students taking linear algebra, I'm projected to pass this course with an A thanks to you!

  • @yusufduman8737
    @yusufduman8737 2 года назад

    I don't know if she is the biggest but she is very big. Thank you Kimberly Brehm, thank you so much..

  • @Asterics.
    @Asterics. Год назад

    Thank you ms. brehm, I finished the course in 16 days, definitely need some recall to all of those. Anyway this course is so helpful for me, I finished an entire course even before the semester is even started yet.

  • @ahmedobn8866
    @ahmedobn8866 Год назад

    Words cannot describe how much I thank you. God bless you❤️

  • @Spatzable55
    @Spatzable55 2 года назад

    Thank you for taking the time to make these helpful videos!

  • @confused6526
    @confused6526 Год назад

    Thank you Prof Brehm. What a great journey!

  • @kumaravelrajan
    @kumaravelrajan 2 месяца назад

    Thanks very much for this lecture series. It was a very quick way to refresh my knowledge on Linear Algebra.

  • @youreyesarebleeding1368
    @youreyesarebleeding1368 2 года назад +2

    Well, my final exam is in 6 hours. Thanks to this series, I will have officially passed Linear Algebra

  • @thumsdown1
    @thumsdown1 3 года назад +1

    I am starting my part-time school. My teachers recommended your channel to re-visit the basics of maths. Surely, I learned a lot more in a simpler way. Thank you for this series.

    • @SawFinMath
      @SawFinMath  3 года назад +2

      That's fantastic! Where are you studying?

    • @thumsdown1
      @thumsdown1 3 года назад

      I would be studying Advanced studies of Wireless Embedded Systems.Digital Signal Processing. I have been working for 8 years. So kind of needed revisiting maths for graduation studies. Surely, the way you give a problem to solve and then go ahead with solution really feels like taking in-person tuition. Thank-you once again.

    • @thumsdown1
      @thumsdown1 3 года назад

      @@SawFinMath ucsd

  • @muhammadfardeen9194
    @muhammadfardeen9194 Год назад +1

    First of all iam going to say that i watched this whole playlist in 5 days before my linear algebra final exam and you taught that much accurate that i knew how to solve tha whole paper may Allah bless you sister ❤

    • @SawFinMath
      @SawFinMath  Год назад

      I love comments like this! So happy to help!

  • @SquidyMeg
    @SquidyMeg Год назад

    Thank you for this I know im 4 years late but im still thankful

  • @buh357
    @buh357 2 года назад

    Thank you so much for your time and effort.
    I am learning a lot from you.
    I wish all the best for you and your family.❤

  • @mokoepa
    @mokoepa 3 года назад

    And today I made it to the last video in the playlist...

  • @nahtalygg
    @nahtalygg 3 года назад

    Thank you so much! You make wonderful content that is easy to understand.

  • @SliverHell
    @SliverHell 5 лет назад +1

    thank you. i really appreciate all of your lessons

  • @nessessence8261
    @nessessence8261 3 года назад +1

    just complete the series, appreciate!

  • @Casual314aA
    @Casual314aA 4 года назад +1

    You are AWESOME. Thank you so much.

  • @WOLF91
    @WOLF91 3 года назад

    Thank you, your videos have been incredibly helpful.

  • @nikolinaeleonor
    @nikolinaeleonor 3 года назад

    Thank you so much! You made me understand linear algebra!

  • @warhammer48
    @warhammer48 Год назад

    Thank you for doing this series it helped me a lot! If you ever go back to do this please add 5.5, 2.8., 2.9, 4.5(Especially 5.5) . That would help future students a ton! Again thank you for doing this.

    • @SawFinMath
      @SawFinMath  Год назад +2

      I may be redoing this series with a different textbook soon (Larson)

  • @larshaji6117
    @larshaji6117 3 года назад

    best teacher I have seen ever, Thanks

  • @ranarafay6880
    @ranarafay6880 3 года назад

    Watched complete playlist, that as very helpful.
    Thanks for this incredible content.
    :)

  • @manjunathreddy777
    @manjunathreddy777 Год назад

    i had an exam tommorow u explained well that iam getting confident abt this topic

  • @johnk8174
    @johnk8174 3 года назад

    nice complement to Strang; thanks.

    • @SawFinMath
      @SawFinMath  3 года назад

      Thanks! I haven't used the Strang text, but most Discrete texts cover 80% of the same material with variations based on the focus of the course.

    • @johnk8174
      @johnk8174 3 года назад

      @@SawFinMath I meant Gilbert Strang as the internet popularizer of linear algebra more than as the textbook author (though his books are wonderful too); I don't know how many millions of views he has for his linear algebra videos on RUclips, but good portion of them were from me :-).
      I meant great praise by comparing you to him.

    • @SawFinMath
      @SawFinMath  3 года назад

      Well thank you so much! I will have to check out his videos!

  • @davidusmonov5148
    @davidusmonov5148 5 лет назад +1

    Great explanations 👍👍👍

  • @tunabirdy3567
    @tunabirdy3567 Год назад

    Thanks for the class. However, this last example should not have free variable since A has independent column vectors so that At * A should be inversible.

  • @kikimobolaji5368
    @kikimobolaji5368 2 года назад

    Thank you for your vidoes. I got 100% on my matrix final :)

  • @gerardtyson2274
    @gerardtyson2274 Год назад

    Are the following topics not covered in this course?
    Cramer’s Rule
    Markov Matrix
    Complex and Hermitian Matrix
    Positive Definite / Semidefinite Matrix
    Markov Matrix
    Singular Value Decomposition
    Change of Basis

    • @SawFinMath
      @SawFinMath  Год назад

      Correct. We don’t cover those topics.

    • @gerardtyson2274
      @gerardtyson2274 Год назад

      @@SawFinMath perhaps you could make a Linear Algebra II course playlist covering those topics

    • @SawFinMath
      @SawFinMath  Год назад +1

      I am considering a refreshed playlist for this course that would cover more topics.

  • @MichaelBomett
    @MichaelBomett 2 года назад

    Much appreciated, very helpful 👍

  • @zuko803
    @zuko803 3 месяца назад

    finally I'm finished this class but I will find the rest of chapter which is chapter 7 in the other channel, I want to say thank you so much, its really help me understand math in machine learning model that I want to learn, thank you maam!

  • @Sayantikadas12
    @Sayantikadas12 5 месяцев назад

    Don't we need to find the b(cap) and hence the error in the last practice question?
    Kindly explain this ma'am.

  • @ceejay1353
    @ceejay1353 11 месяцев назад

    So Just want to be clear, is this course at this point enough to have a foundaila understanding to move onto other Compsci /Math Courses that need it?

  • @thantzinmaung-yq6cu
    @thantzinmaung-yq6cu Месяц назад

    came in clutch

  • @VALOGAMERPK
    @VALOGAMERPK 3 года назад

    thanks professor Brehm

  • @lsjmartin6220
    @lsjmartin6220 6 месяцев назад

    This is The END...

  • @boggavarapunikhil2745
    @boggavarapunikhil2745 4 года назад +1

    Thank you so much for great explanations.

  • @muhammadabdullahriazbhatti
    @muhammadabdullahriazbhatti Год назад

    did you skip gram schmidt process for 6.4?

    • @SawFinMath
      @SawFinMath  Год назад +1

      Yes. We don’t cover that in my class so I didn’t make a video for it.

    • @muhammadabdullahriazbhatti
      @muhammadabdullahriazbhatti Год назад

      @@SawFinMath You probably skipped Singular Value decomposition from chapter 7, also. Is that right?

  • @angelasmith7894
    @angelasmith7894 4 года назад

    For the last problem wouldn't we still need to calculate b hat and the error? Those were steps 4 and 5 in the second to the last problem, but not in this problem..

    • @SawFinMath
      @SawFinMath  3 года назад

      Since we weren't asked for the error, I didn't complete that step.

  • @lgl_137noname6
    @lgl_137noname6 3 года назад

    Professor Brehm,
    Thank You so very much for your presentation of this material.
    Very effective.
    Will there be follow up courses with presentations of SVD ?
    Please advise,
    Regards
    GL

    • @SawFinMath
      @SawFinMath  3 года назад

      Thanks for watching. I have no plans at this time for SVD. I teach undergraduate mathematics and that topic is not in our topic list

  • @cameronsantiago3155
    @cameronsantiago3155 3 года назад

    And we are done!

  • @einayis
    @einayis 2 года назад

    hi Madam Brehm! is the video 6.4 and 4.4 missing?

    • @SawFinMath
      @SawFinMath  2 года назад +1

      I don't cover all sections in the textbook

    • @einayis
      @einayis 2 года назад

      @@SawFinMath I see 😊

  • @amon6743
    @amon6743 3 года назад

    Thank you very much

  • @confused6526
    @confused6526 Год назад

    Prof Brehm..
    Throughout the lectures you kept saying "check...check but I only see that you did one "check" using the Nike symbol 😃
    Then .. in this lecture I realized why you kept saying "check..check". By that you you meant one check down (\) and then another check up (/). So the final of "check.. check" = \/.
    😃

  • @tamsaasoo5418
    @tamsaasoo5418 9 месяцев назад

    GOAT

  • @ahmedmusa517
    @ahmedmusa517 3 года назад

    Hello, can I calculate b-hat by projecting b on A ? then I can easily calculate x-hat by taking Ax=b-hat

    • @SawFinMath
      @SawFinMath  3 года назад

      I don't believe so, but you can give it a shot and let me know how it turns out!

    • @ahmedmusa517
      @ahmedmusa517 3 года назад

      @@SawFinMath Hiii it did work I got the same result ! but I had to use Gram-schmidt process first because the basis of subspace are not orthogonal. It is vert easy method coz I did not calculate the AT A and AT B ....etc

  • @mohammadhamzaali6619
    @mohammadhamzaali6619 Год назад

    the RREF for this is actually
    1 0 0 1 3
    0 1 0 -1 -5
    0 0 1 -1 -2
    0 0 0 0 0
    slight mistake but awesome video overall!

  • @njoy2075
    @njoy2075 4 года назад

    why in Step 4 we can not use the generic formula b^=Sum((b.u/u.u).u) ??

    • @SawFinMath
      @SawFinMath  3 года назад

      Does it give you the same result?

  • @angelmoronta3771
    @angelmoronta3771 Год назад

    thank youuuu!!!!!!!!!!!!!!!!!

  • @ivanminchev888
    @ivanminchev888 Год назад

    tysm

  • @davidusmonov5148
    @davidusmonov5148 5 лет назад +2

    Wow, great videos. Thanks a lot. Can you give your brain just for one day?🙃 I need to pass my exams. Anyway I trying to copy your brain

    • @SawFinMath
      @SawFinMath  3 года назад +1

      You don't need it! I bet you did great on your own!