Finding the Inverse of a 3 x 3 Matrix using Determinants and Cofactors - Example 1

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  • Опубліковано 9 лют 2025
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    Finding the Inverse of a 3 x 3 Matrix using Determinants and Cofactors - Example 1. Besides using row reduction, this is another way to find the inverse of a 3 x 3 matrix.

КОМЕНТАРІ • 813

  • @Howsonify
    @Howsonify 10 років тому +664

    For those who want a simpler method for 5:10 and on (without "reflecting things about the diagonal"): Just *transpose* the matrix, which means the first row becomes the first column. The second row become the second column. The third row becomes the third column. The nth row becomes the nth column. It's easier to remember this way.

    • @anuprandive5145
      @anuprandive5145 7 років тому +8

      Thanks

    • @ssss855167
      @ssss855167 5 років тому +4

      Thank you.

    • @dremr2038
      @dremr2038 5 років тому +4

      That is adjoint, right?

    • @osmanmehmood3580
      @osmanmehmood3580 5 років тому +19

      @@dremr2038 Yes, finding the cofactor of each element of the matrix and transposing it, gives us the adjoint of the matrix in question. Dividing that by the determinant of the original matrix gives us the inverse of the matrix.

    • @JamateSirajiaFaisalabad
      @JamateSirajiaFaisalabad 4 роки тому +1

      Ok

  • @SuperFerdie1965
    @SuperFerdie1965 6 років тому +64

    I've been a maths tutor for 42 years and I haven't the faintest idea why this works! Thanks for a very good demo.

    • @karanbharadva9820
      @karanbharadva9820 2 роки тому +9

      Wasted 42 years

    • @SuperFerdie1965
      @SuperFerdie1965 2 роки тому +19

      @@karanbharadva9820 I wouldn't say that a millionaire tutor has wasted his time tutoring!!

    • @karanbharadva9820
      @karanbharadva9820 2 роки тому

      @@SuperFerdie1965 haha lol 😁

    • @SuperFerdie1965
      @SuperFerdie1965 2 роки тому +1

      @@karanbharadva9820
      Not all are losers and morons like yourself my poor little troll!

    • @metaverse413
      @metaverse413 Рік тому +1

      @@SuperFerdie1965 sounds like a 9 years old to me

  • @vikkalkat2241
    @vikkalkat2241 10 років тому +192

    thank you so much! after i graduate and work full time, my first paycheck will be sent to you

  • @chillindylan1786
    @chillindylan1786 10 років тому +805

    I don't think you understand...YOU JUST SAVED MY LIFE. Guess who gon turn that D to a B- baby...this guy Let's GOOOOOOOOOO!

  • @crunchiecat
    @crunchiecat 11 років тому +269

    every lecturer/teacher should just show this in class rather than saying a word out their mouth

  • @chriswilliams5291
    @chriswilliams5291 2 роки тому +7

    I've watched quite a few videos on finding the inverse of a 3 x 3 matrix and so far your method seems like the easiest way to do it without making mistakes. Thanks for sharing!

  • @isabellatieu8404
    @isabellatieu8404 9 років тому +3

    I've already thanked you on another video, but I just can't thank you enough! My prof spent 1.5 hours on each matrix topic. None of it made sense and some people even got up to leave in the middle of lecture. Thank you for making everything 100% clear.

  • @cleomanloloyo1950
    @cleomanloloyo1950 8 років тому +3

    different generations are going to watch this video of yours over and over again :-) thank you so much patrick :-)

  • @sangeetharamamurthy8628
    @sangeetharamamurthy8628 9 років тому +21

    This video literally saved me from failing my midterm! You're incredible!!!!

  • @TOFFY-kd7pe
    @TOFFY-kd7pe 5 років тому +8

    What my teacher says :
    "It's simple :" *Complicated, incomprehensible stuff on the board wich he erases every seconds*
    Him :
    *Explains ORALLY an actual simple method in addition of explicitly witting it down AND doing it on UA-cam, giving us the ability to pause or rewind.*

  • @lifewithdylan
    @lifewithdylan 7 років тому +208

    not all heros wear capes

    • @wentworthmiller1890
      @wentworthmiller1890 6 років тому +6

      Let's see, Steve, Tony, Banner, Natasha, Parker, Barton, ... then there's Xavier, Logan, Summers, Grey, Wade, ... there's just too many. On the contrary, there's Loki. And Erik. And let's not forget M. Bison either. Sure, there's Strange and Thor, but they're a minority, right, that others don't seem to fancy it? So yeah, you're spot on. Rather, 'tis the baddies that are more drape-inclined.

    • @pluto40433
      @pluto40433 6 років тому

      @@wentworthmiller1890 lmao

    • @user-rf4vc7mt4d
      @user-rf4vc7mt4d 6 років тому

      @@wentworthmiller1890 sir...SIR!

    • @NMQ098
      @NMQ098 6 років тому

      they wear rings instead

    • @andreaelan7267
      @andreaelan7267 6 років тому

      Some drop pens

  • @theshouter3285
    @theshouter3285 Рік тому +219

    Anyone in 2024?❤

  • @MrCtown8
    @MrCtown8 11 років тому +19

    My professor barely speaks English, these videos are so useful! thanks

  • @jarlhamm
    @jarlhamm 6 років тому +1

    You are simply the best man, I have been learning math from you since my remedial courses 3 years ago. Thank you from the bottom of my heart. When I graduate and get a job, there will for sure be a fat donation from me. I owe you so much.

  • @rampatel4817
    @rampatel4817 5 років тому +1

    I’m watching this dude 9 years later and he saved me thanks

  • @iki0o
    @iki0o 11 років тому +124

    i love you man. i remember watching your vids in high school :) now im in final year of engineering undergrad and still come back to these vids

  • @canadianthroneholder
    @canadianthroneholder 10 років тому +169

    Why do these formulas work, who came up with this method for finding the inverse of a 3x3 matrix and what was going through his head at the time?

    • @thabi.b7128
      @thabi.b7128 10 років тому +11

      I Know what you mean like gezz.. some guy comes up with a method then others find a better way to do what you came up with... like WTF... its so Heavy..

    • @canadianthroneholder
      @canadianthroneholder 10 років тому +8

      Mthabisi Bokete with linear algebra in general i see a lot of fancy tricks and algorithms for solving problems but never a proof showing why they work

    • @kdu8004
      @kdu8004 10 років тому +8

      Marcus Fenix Aliens.

    • @derekroolz
      @derekroolz 10 років тому +7

      Marcus Fenix You don't want to see the proofs lol. Well, some are easy and some are harder, some are very trivial, but extraordinarily long. Determinants revolves a lot around matrix multiplication. Matrix multiplication's proof isn't too bad if you remember your matrix as a set of vectors in the defined r-space.

    • @canadianthroneholder
      @canadianthroneholder 10 років тому +3

      derekroolz I saw some wikepedia proof for the cofactor expansion and didn't understand it at all

  • @jinxIomI
    @jinxIomI 11 місяців тому

    13 years later and you're still helping people with this video ❤ thank you

  • @davidontiveroz8295
    @davidontiveroz8295 7 років тому +1

    man, having finished Diff Eq 2 years ago, i thought i would never hear Patrick's sweet soothing voice again. yet here i am for some review for solid modeling, and that voice is as beautiful as ever:')

  • @syd_jzx100
    @syd_jzx100 8 років тому +3

    6 years later and you're still saving lives. Thanks a tonne!

    • @witsuz1
      @witsuz1 19 днів тому +2

      14 years later and he's still saving lives

    • @syd_jzx100
      @syd_jzx100 19 днів тому

      @witsuz1 Wow my comment was 8yrs ago...

  • @avonbarksdale418
    @avonbarksdale418 6 років тому +7

    5:25, It can also be referred to finding the transpose or adjoint of the matrix. The rows become columns, and the columns become the rows. Good job.

    • @its_houssem
      @its_houssem 8 місяців тому

      Yeah this is the trick !

  • @karim4388
    @karim4388 7 місяців тому +1

    U aploaded in 2010...and it is useful for me in 2024..... Take love broo❤

    • @patrickjmt
      @patrickjmt  4 місяці тому

      thanks! glad that i could help you after all this time :)

  • @emrglr6963
    @emrglr6963 9 місяців тому

    your videos still work like magic in 2024. I passed my calculus courses thanks to your videos 10-11 years ago.

    • @patrickjmt
      @patrickjmt  9 місяців тому

      glad i could still help :)

  • @khanhcamhoang2118
    @khanhcamhoang2118 2 роки тому +1

    thank you good sir, 12 years later!

  • @Adoptme_user.
    @Adoptme_user. 3 місяці тому +1

    If you see a video with one black marker and paper ,that person can save your life✨

    • @patrickjmt
      @patrickjmt  3 місяці тому

      ha :) too bad all of my new videos are made digitally. the days of pen and paper are over for me! end of an era...

  • @Zaratron-rd1jk
    @Zaratron-rd1jk 10 років тому +8

    You are actually amazing with this video. Khan academy was so crazy. I watched this and understood immediately. Thanks so much. Got a test on friday, gonna ace it now :3 CANNOT SAY THANKYOU ENOUGH!!

    • @patrickjmt
      @patrickjmt  10 років тому +7

      Glad you like my videos!

    • @Zaratron-rd1jk
      @Zaratron-rd1jk 10 років тому +3

      I did indeed! I finally used it today and aced it! xD Thanks so much again for taking the time to help others! (:

  • @sabaharefin4852
    @sabaharefin4852 10 років тому

    this is so much better than reading the book and reading the examples which doesn't make much sense most of the time... thank you for making it easy.

  • @legendsplayground7017
    @legendsplayground7017 3 місяці тому

    mayn i'm having my test tmr, i don't quite understand what my teacher was saying in the class, glad that i find ur video, keep up the good work, Jesus bless

  • @patrixemary2187
    @patrixemary2187 4 роки тому +2

    i've been trying to understand this lesson which was never discussed by our prof and u just saved lives :(( thank u

  • @mumbakondowe6839
    @mumbakondowe6839 3 роки тому

    This guys deserves a pat on the back for making it look this easy

  • @chilldoggy4721
    @chilldoggy4721 Рік тому

    Thank you. Watching this 1 hour before my exam, learned something new

  • @friedbabyfingers
    @friedbabyfingers 11 років тому +16

    Why can't teachers be this straight forward?

  • @minttea9140
    @minttea9140 3 роки тому

    I know this is an 11 year old video, but sir, wherever you are now, bless you!!! I had a breakdown after my first math class because the professor did not explain this well at all, but just after watching this video I understand it all :D

  • @JustinRoy-hv7bt
    @JustinRoy-hv7bt 8 місяців тому

    This is much more helpful am sure I'll be doing my maths activities following this steps accordingly..Big thanks to the source, you're powerful!🎈🙏

  • @williamyuhanhou5170
    @williamyuhanhou5170 5 років тому

    finding an inverse is a truly painful process, but u did it in a way that made me understand it.

  • @sayem.wayeez
    @sayem.wayeez 2 роки тому +1

    Such a great video for learning.
    I have been struggling with this math a lot. After seeing this video this math seems like so easy for me. You have a great skill of teaching. Keep it up. May Almighty bless you. Love from Bangladesh 🇧🇩

  • @googleuser4577
    @googleuser4577 5 років тому +3

    YOUR WRITING IS AMAZING

  • @pd7009
    @pd7009 8 років тому +1

    you are like the most useful math teacher on the whole of youtube, thanks!

  • @oreeku_
    @oreeku_ 11 днів тому

    A soul you helped here too❤
    Got exams tomorrow, don’t know why i always wait a night to exam before i begin reading, lool

  • @marrinnalee2978
    @marrinnalee2978 Місяць тому

    Thank you so much for the explanation! I just gained more confidence for my Uni. Maths exam tomorrow

  • @shookycooky5498
    @shookycooky5498 2 роки тому

    I WAS LITERALLY DOOMED BEFORE WATCHING THIS VIDEO ........ YOU ARE TRULY INCREDIBLE TYSM!!!!

  • @rpf19
    @rpf19 12 років тому +1

    I LOVE YOU. literally spent two days trying to do this and you teach me it in 7 minutes, thank you so much

  • @alfredmerin5445
    @alfredmerin5445 2 роки тому

    Did you know that you just help me understand this lesson easily? THANKYOU SO MUCH!!!!🤣🤣

  • @fakihababar
    @fakihababar 3 роки тому

    I have an exam in about 3 hours and you just saved my life thank you soooo muchh

  • @systempatcher
    @systempatcher 7 років тому +135

    You confused me with the whole diagonalization thing. Took me a second to realize it's just a transpose lol...

  • @Sai-pi4wq
    @Sai-pi4wq 11 місяців тому

    AHHHH I remember my teacher doing this method in the class but I forgot it. Thank you so much!! Hope I can use this is my exam tomorrow.

  • @mohitshirpurkar9455
    @mohitshirpurkar9455 4 роки тому

    Thanks for making the video I understood it within 1 minutes and now I can solve every inverse questions in 3-5 minutes.

  • @patrickjmt
    @patrickjmt  13 років тому +6

    @gudefeda i freakin' love the internet. i am old enough to remember when our school got our first computer in 4th grade, when the family got an atari 2600, when i got my first computer at home ( run dos, run), dial up modems that took 10 hours to load a picture, and finally, a good internet connection. god bless al gore for inventing the internet

  • @nafcatt8863
    @nafcatt8863 4 роки тому

    You have taught me what my professor couldn’t in the last 3 2-hour lectures

  • @francinengendakuriyo3444
    @francinengendakuriyo3444 7 місяців тому

    He literally explained in 6 minutes what my teacher couldn't in 3 hours

  • @shubhambhardwaj4428
    @shubhambhardwaj4428 7 років тому

    i have got 85 in preboard only by you in maths because i follow you in writing steps of method you are nice teacher
    thanks for help me in gettting 85/100 thanks

  • @Judyangieli
    @Judyangieli 11 років тому

    OMG the only person who I actually understand when it talk about numbers!!!

  • @suvasish.dey.sarker.bangladesh
    @suvasish.dey.sarker.bangladesh 7 років тому

    I have a midterm tomorrow, thanks a ton brother!
    I'm hopefully gonna ace it tomorrow thanks to you!
    Love from Bangladesh!

  • @dan-bf5ie
    @dan-bf5ie 2 роки тому

    thank you, this is saving me 2 hrs before my exam

  • @wanni_zr842
    @wanni_zr842 5 років тому

    my lecturer showed me the rref way, just found this is more useful and spend less time. Thank you!!!!

  • @bullterry14
    @bullterry14 10 років тому

    thumbs up if this guy is like your second and most useful teacher

  • @artNik__
    @artNik__ 6 років тому

    i saw this video just b4 my exam n i understood the entire topic, thanks man

  • @riyaprajapati9501
    @riyaprajapati9501 Рік тому +1

    Good thank you so much 😤😤😤❤❤❤

  • @serajsersawi5786
    @serajsersawi5786 6 років тому

    In case someone is confused It's called "finding the inverse of A using the adjoint of A"
    Where the adjoint of A = the transpose of the Cofactor matrix C ... adj = C^T

  • @jamiewu5618
    @jamiewu5618 10 років тому +44

    Holy mother of god, my brain is fried.

    • @Mr-WesleySnipzzz
      @Mr-WesleySnipzzz 7 років тому +2

      My brain exploded

    • @Peter-bg1ku
      @Peter-bg1ku 3 роки тому

      In my opinion, the only difficult part of this tedious process is avoiding making small mistakes. The concept itself is fairly easy to grasp.

  • @박서준-b6d1k
    @박서준-b6d1k 3 роки тому

    Awww he is such a good teacher🥺❤️✨💜stay blessed ly❤️❤️

  • @adeola9865
    @adeola9865 2 роки тому

    THANK you so muchhhhh
    i have an exam today and if this comment is still here then you'll know it went well cuz of you

  • @GLDN06
    @GLDN06 3 роки тому

    Your a legend dude. YOU SAVED ME WEEKS!

  • @prabhakarramachandran9784
    @prabhakarramachandran9784 6 років тому +1

    This could never get even more clear to me. Thank you soo much

  • @AmanKumar-te8ft
    @AmanKumar-te8ft 5 років тому

    This is the method for which I was looking for about an hour.
    Thanks🙏🙇

  • @shanielching6868
    @shanielching6868 Рік тому

    Trust me I found it hard to find a strategy for finding co factors ..... And u jxt made it look so easy thank u

  • @gudefeda
    @gudefeda 13 років тому

    thanks a bunch. the internet teaches me more math than my teacher does!!!

  • @kimiko495
    @kimiko495 Рік тому

    wow this is really complex, but you explained well and I understood the procedures, thanks a lot!

  • @bright4931
    @bright4931 4 роки тому +1

    Did I say I love u?i love u ....u saved me.

  • @bryceconner5371
    @bryceconner5371 3 роки тому

    Haven't watched in some time.. coming back to review for the FE Exam. Just like old times

  • @DaLeR080
    @DaLeR080 9 років тому

    Who the f**k puts dislikes ?! You are just awesome Patrick. I am studying computer engineering and your videos are really helpful. Your discrete math lessons are also great . THANK YOU !!!

  • @ibrahija
    @ibrahija 11 років тому

    I love you. My math test is tomorrow and you sir , I thank you !

  • @varungoyal4732
    @varungoyal4732 5 років тому

    THANK YOU SO MUCH PATRICK! YOU JUST SAVED MY LIFE.

  • @benitocarlos0
    @benitocarlos0 4 роки тому +5

    Long time no see you, my friend. Just doing a semester in modern controls in EE and I am studying for the final that will probably have this. Thanks for your work.

  • @ahmadfahim7283
    @ahmadfahim7283 3 роки тому

    Thank you so much Patrick!
    I was the only one who was laughing after the exam.😉

  • @davida6386
    @davida6386 7 років тому

    wow makes a lot more sense now. thank you. Tedious work but doable

  • @cookiesncream8490
    @cookiesncream8490 6 років тому

    Have a sudden quiz today and this really save my life thanks so much

  • @no2475
    @no2475 13 років тому

    Dude thank you so much for these videos!
    My teacher sucks. :|
    She flies trough everything on rocket speed like it's a race or sumtin and I'm never able to follow properly...
    I learned more from your videos than I did from her.

  • @emandleni1735
    @emandleni1735 8 років тому +25

    You're a legend!

    • @patrickjmt
      @patrickjmt  8 років тому +3

      Thanks! :)

    • @fredijacksi9801
      @fredijacksi9801 7 років тому

      patrickJMT I'm going to take my entrance exam for M.A Economic..so would you mind calculating some of my doubt questions for me ? plss...I will be grateful if you do so..pls leave me your email address here or any social network where I can post my questions series. thank you!

  • @patrickmorel1809
    @patrickmorel1809 12 років тому

    A couple of hours before my exam, you actually saved my as*, And totally owned me teacher's metods. ( got 91% )!!!

  • @burningburgerx4023
    @burningburgerx4023 3 роки тому

    much simpler and easier than school
    thanks for the help!!

  • @nerfMango
    @nerfMango Рік тому

    Thankyou bro i have Exam tomorrow finally understood.🎉🎉🎉
    Thankyou very much

  • @gafourfaiza2525
    @gafourfaiza2525 9 років тому

    thank u so much it was so helpful and easy to understand ( i study in frensh and am not very good in english ) good Luck 😊

  • @Khaielaash94
    @Khaielaash94 12 років тому +4

    You don't know how much you're helping me in A Level Further Math. :D
    Also, without you, I wouldn't be able to do implicit differentiation at all, which is actually really easy. Not that my teacher is bad, I just lost my way at some point.
    All I have to say is, thank you! :D

  • @sabrinaalgoo1822
    @sabrinaalgoo1822 9 років тому +1

    you're the best teacher on youtube to my knowledge thank you :DDDDDDDDDDDDD

  • @nikhilkoirala8633
    @nikhilkoirala8633 6 років тому +3

    Thank you so much. It really helped me alot

  • @sandeepkashetty455
    @sandeepkashetty455 7 років тому +1

    awesome sir.very interesting,thanks for teaching the 3*3 matrix very easily

  • @asnsr3573
    @asnsr3573 9 років тому

    Mr.Patrick sir, I can't express how thankful I am, God bless you, you really helped me a lot (THANK YOU)

  • @zainabkhan8479
    @zainabkhan8479 3 роки тому

    Thank you soooo much!😭❤️❤️❤️❤️❤️
    Tomorrow I have my maths exam

  • @JasonChamberlain
    @JasonChamberlain 12 років тому

    dude. you are one of the most helpful people out there.

  • @craigdow5566
    @craigdow5566 12 років тому

    Man thanks to your video's I may actually pass my exam tomorrow. Cheers!

  • @rajendramisir3530
    @rajendramisir3530 3 роки тому

    Good work Patrick. Identifying the matrix of minors, matrix of cofactors and the adjoint matrix will help viewers follow and understand the various steps in arriving at the inverse matrix of the original 3 by 3 matrix.

  • @samuelcampbell7726
    @samuelcampbell7726 7 місяців тому +1

    Simple and. Precise

  • @share-up3503
    @share-up3503 8 років тому

    you are amazing, thank you for helping me, i have a maths test next friday! much love from Portugal!

  • @manojkumarsubramaniam7122
    @manojkumarsubramaniam7122 7 років тому

    Thanks bro.. You saved my midterm...

  • @ronaldkisitu8401
    @ronaldkisitu8401 4 роки тому

    You really deserve a giant gift

  • @paromitaroy5861
    @paromitaroy5861 4 роки тому

    Idk about everyone else but the diagonals helped me quite a bit

  • @shaishavsaraswat3791
    @shaishavsaraswat3791 10 років тому

    For some weird reason my OCD was kicking in while you were writing with your left hand. Awesome video btw...Thank You...!

  • @Melo-mn1kd
    @Melo-mn1kd 7 років тому

    bruh ...my teacher is a frikking donkey!!
    tomorrow is my exam n here u r with an amazing explaination!
    thank u!!!!!!

  • @SmashBrosBrawl
    @SmashBrosBrawl 8 років тому

    It's so easy to goof up in Gauss elimination.
    Thank you