Examples: A Different Way to Solve Quadratic Equations

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  • เผยแพร่เมื่อ 23 ธ.ค. 2024

ความคิดเห็น • 1.6K

  • @BravoTango-vt8em
    @BravoTango-vt8em 4 ปีที่แล้ว +550

    This is the type of math teacher I like. The teacher who actually lets their kids understand the math instead of making them pass the exam so he doesn’t have to worry about it again.

    • @muhammadazeem9775
      @muhammadazeem9775 4 ปีที่แล้ว

      th-cam.com/video/L4ImyFn1xLk/w-d-xo.html

    • @ashishkushwaha2214
      @ashishkushwaha2214 3 ปีที่แล้ว +4

      Right bro

    • @aravinds3846
      @aravinds3846 3 ปีที่แล้ว +7

      I wish I saw this lecture before JEE exam lol. The graph method makes the questions INCREDIBLY easy

    • @ooffoo5130
      @ooffoo5130 3 ปีที่แล้ว +5

      he also has an iq of like 230 so that might have something to do with it

    • @antoniofuller2331
      @antoniofuller2331 3 ปีที่แล้ว

      Hmm

  • @jimspelman8538
    @jimspelman8538 4 ปีที่แล้ว +112

    I am a math and computer science major and a math teacher (middle school) and, like others have commented, I have never seen this method before. I love how you can easily get non-integer solution sets! Perhaps instead of the "Po-Shen Method" I shall henceforth call this the "Magic Quadratic Po-Shen" (just to add a little wordplay)!

    • @chocolateangel8743
      @chocolateangel8743 3 ปีที่แล้ว +1

      I saw a video in which a college professor did the same thing -- because he couldn't remember how to pronounce his name.

    • @Tweeting_data
      @Tweeting_data 2 ปีที่แล้ว +1

      Portion

  • @robertmcfarlane8546
    @robertmcfarlane8546 5 ปีที่แล้ว +400

    This is one of the best lectures on quadratic equations I have seen. Thank you Mr Loh for clear and understandable information presented in a concise manner.

    • @psloh
      @psloh 5 ปีที่แล้ว +10

      Thanks for your feedback!

    • @Thecannibalfrombeyond
      @Thecannibalfrombeyond 4 ปีที่แล้ว

      @@psloh sir, could you please reply me??

    • @muhammadazeem9775
      @muhammadazeem9775 4 ปีที่แล้ว

      th-cam.com/video/L4ImyFn1xLk/w-d-xo.html

    • @d.chandrasekara7959
      @d.chandrasekara7959 2 ปีที่แล้ว

      Why 14 doesn't become -14 as in x^2-14x+24, can someone explain it pl

  • @norbertotorbeso2562
    @norbertotorbeso2562 5 ปีที่แล้ว +18

    I have been teaching this method to my high school students back in 1999 and yes, this is another way. Students will definitely learn if a teacher will expose them to different ways of solving the problem. Nice presentation...

    • @geraldillo
      @geraldillo 4 ปีที่แล้ว +3

      I realise that this is basically not much different than completing the square. Why was this method not widespread before? It would have saved many students a whole lot of suffering...

    • @Latronibus
      @Latronibus 2 ปีที่แล้ว +1

      @@geraldillo The one thing I don't like about this method relative to completing the square is that it doesn't teach the "add and subtract" trick, which is useful elsewhere in math. To clarify what I mean, I think of completing the square in this kind of format: x^2+2x+2=x^2+2x+1-1+2=(x+1)^2+1. The "I can just put a +1 there as long as I take it away later" concept is kind of magical to an algebra student, but is widely used elsewhere in math. Unfortunately I sometimes see students learning this in terms of adding the desired quantity to both sides of an *equation* which is really the less common way to think about it in more advanced math.

  • @rajeevmaakan1347
    @rajeevmaakan1347 4 ปีที่แล้ว +87

    I salute you man! This is absolutely amazing....have been teaching math for 35 years, you have just made my job easier for whatever remaining number of years I will be able to teach. That's why they say....it doesn't matter you learned something new so late in life, what matters is you got new knowledge (new, I say, for the learner), new wisdom. And last but not the least, what is the primary objective of Problem solving....in any branch of knowledge or education....it is to achieve the objective in as simple and as uncomplicated a manner as possible....so that it can bring a smile on the faces of our students. Thanks a zillion bro!!!

    • @User00159
      @User00159 2 ปีที่แล้ว +2

      Sir pls do research on vedic maths which will change your life 🇮🇳🇮🇳

  • @johankotze42
    @johankotze42 4 ปีที่แล้ว +7

    Dear Prof Loh, I am now retired at 61, and I have worked in IT for most of my working life. I have, however, always dabbled in mathematics. The thrill of discovering this only recently, is one the reasons for my continued love of the subject. If you have not done so, adding the graphical interpretation would help many other students. Thank you very much.

    • @southernkatrina8161
      @southernkatrina8161 4 ปีที่แล้ว

      Could we try it on Desmos?

    • @johankotze42
      @johankotze42 4 ปีที่แล้ว

      @@southernkatrina8161 Desmos?

    • @southernkatrina8161
      @southernkatrina8161 4 ปีที่แล้ว +2

      Desmos is a free download app that takes a function and graphs it. It's good fun and helps learning.

    • @chocolateangel8743
      @chocolateangel8743 3 ปีที่แล้ว +1

      I had to find videos that explained it, graphically, in order to fully understand what was going on.

  • @RavinaTutorial
    @RavinaTutorial 5 ปีที่แล้ว +149

    Sir please keep posting such methods so that people start analyzing mathematics and taste the true essence of it, Thank you so much for sharing this🙏.

    • @psloh
      @psloh 5 ปีที่แล้ว +11

      :)

  • @blockyboxhead
    @blockyboxhead 2 ปีที่แล้ว +2

    I watched this entire video without getting bored or wanting to click off. This proves that this video is godly

  • @harisomerbasic9136
    @harisomerbasic9136 4 ปีที่แล้ว +89

    My teacher had me explain this to her and now she's recommending your technique and referencing to you! Thanks from Sweden!

    • @harisomerbasic9136
      @harisomerbasic9136 4 ปีที่แล้ว

      not your but as a tip

    • @jackeroo75
      @jackeroo75 4 ปีที่แล้ว +2

      Of course other countries know this while USA still wants kids to learn the route method

    • @muhammadazeem9775
      @muhammadazeem9775 4 ปีที่แล้ว

      th-cam.com/video/L4ImyFn1xLk/w-d-xo.html

    • @LiveHappy76
      @LiveHappy76 3 ปีที่แล้ว +1

      @@muhammadazeem9775 Just a tip, based on my personal preference. I almost never click on a video link that does not include a brief statement of what the content/summary of that video is...you'll attract more clicks with a brief statement. Nice rose picture.

  • @tordjarv3802
    @tordjarv3802 2 ปีที่แล้ว +1

    Just to make it clear, the method presented in this video is not new in any way. It is just a relabeled version of the well known PQ-formula being taught to high school students all around the world. The algorithm in the beginning is just a common derivation of it. However, there is nothing wrong with the video it self. It is one of the most pedagogical videos on quadratic equations I have seen, good job on that.

  • @g.v.3493
    @g.v.3493 4 ปีที่แล้ว +11

    I’m reviewing all of my precalculus math that I had 50 years (!) ago. I wish I’d had you for a math teacher back then. Thank you so much for the teaching an old dog a new trick! I’m planning to learn a lot more new tricks. I’ll be watching more of your videos in the future! Thanks so much!!

  • @gautamghaisas
    @gautamghaisas 2 ปีที่แล้ว +12

    I wish we could have learnt all subjects this way in school. So systematically and brilliantly explained

  • @trudyandgeorge
    @trudyandgeorge 5 ปีที่แล้ว +12

    This is so elegant, intuitive, and forces the solver to think about what's happening and how things relate to each other. I wish I had TH-cam back when I was in school.

    • @gregnixon1296
      @gregnixon1296 4 ปีที่แล้ว

      If there were TH-cam when I was in school, I would never have gone to school. Attendance and tuition would have been a waste of resources.

    • @carolinebrown7634
      @carolinebrown7634 4 ปีที่แล้ว

      VIO stand your life.

  • @sandanadurair5862
    @sandanadurair5862 3 ปีที่แล้ว +4

    You are simply great.
    I have never seen such a pleasant mathematics teacher during my learning period. I am now 72. Today you taught me a novel technique. I salute you

  • @geraldillo
    @geraldillo 5 ปีที่แล้ว +292

    Every highschool teacher should learn this method

    • @rukmaniranganathan8420
      @rukmaniranganathan8420 4 ปีที่แล้ว +7

      Yes

    • @Jesusisgreat117
      @Jesusisgreat117 4 ปีที่แล้ว +3

      True talk

    • @muhammadazeem9775
      @muhammadazeem9775 4 ปีที่แล้ว +1

      th-cam.com/video/L4ImyFn1xLk/w-d-xo.html

    • @chandasubba3502
      @chandasubba3502 4 ปีที่แล้ว +1

      X²+6x-27=0

    • @devonyumen8116
      @devonyumen8116 4 ปีที่แล้ว +1

      No plssss. This is complicated 😭😭 like why can't we just use the quadractic formula. It isn't that difficult to remember 😔

  • @dananewborn8926
    @dananewborn8926 3 ปีที่แล้ว +2

    Thank you from my 19 person math class who enjoyed learning this method

  • @philplante6524
    @philplante6524 2 ปีที่แล้ว +13

    The method at 00:46 is just the quadratic formula. - B/2A +- u, where u^2 = B^2/4 - AC. The x-coordinate of the vertex of a parabola is -B/2A. It is also the line of symmetry. If you extend the line of symmetry through the x-axis, you will see that one root is a distance SQRT(B^2 - 4AC) to the right and the other is a distance -SQRT(B^2 - 4AC) to the left. The method is a bit different than just plugging numbers into the quadratic formula, but there is really no new math here, just a different way to apply the quadratic formula.

  • @beteilniguse8072
    @beteilniguse8072 4 ปีที่แล้ว +24

    This is exactly how we learned in my country East Africa. God how did I forget this, and our professor has zero clue and got me confused and spent days to really figure this out. I wish I found you early. I would have saved a lot of time. But thank you so much! You did an amazing job. keep them coming.

  • @espenvang3053
    @espenvang3053 4 ปีที่แล้ว +34

    What a marvellous lecture in every way! Not just a genius new method for solving quadratic equations, but also clear and precisely presented.

  • @heaslyben
    @heaslyben 2 ปีที่แล้ว +3

    What a joy that this method fits naturally in each number domain! The intuition of "finding the average" leads so smoothly into creating a complex conjugate pair. It's as if we knew more than we knew we knew, all along. Thanks for sharing this so well!

  • @joebrinson5040
    @joebrinson5040 5 ปีที่แล้ว +59

    I have never seen this method. Beautiful. Thank you. Retired math teacher.

    • @psloh
      @psloh 5 ปีที่แล้ว +15

      Thank you for your career of teaching!

    • @muhammadazeem9775
      @muhammadazeem9775 4 ปีที่แล้ว

      th-cam.com/video/L4ImyFn1xLk/w-d-xo.html

    • @jecelaguilar9319
      @jecelaguilar9319 4 ปีที่แล้ว

      Haven't you taught your students one of the methods in finding for the roots of a quadratic equations is by completing the perfect square trinomial? This method is used how we arrived at the so-called quadratic formula😀

    • @chocolateangel8743
      @chocolateangel8743 3 ปีที่แล้ว +1

      @@jecelaguilar9319 At first, I didn't get what he was doing. So, I Completed The Square on a couple of problems, using an area model. I'm a really visual and conceptual math learner, so things like area models really help me. After I did some problems, I realized that his method is basically a shortcut for Completing The Square. I had the idea because he said his method always works. To those of us in the U.S., this approach seems different because it's not the exact way we are taught to Complete The Square in school.

  • @harshdeeprandhawa5872
    @harshdeeprandhawa5872 3 ปีที่แล้ว

    shoutout to people like this on youtube for carrying us through school single-handedly. THANKYOU

  • @wreckim
    @wreckim 3 ปีที่แล้ว +19

    As a 4th grade teacher, I can tell you that it would be incredible to have this kind of talent exposed to the kids right from 1st grade on. So much of the math problems we have is because we lack our natural curiosity and stop having fun. Math gets to be all about 'testing' pretty quick once they leave 6th grade. Thanks for posting, great lesson.

    • @jenm1
      @jenm1 3 ปีที่แล้ว

      You could teach them!

  • @belmer73
    @belmer73 5 ปีที่แล้ว +2

    I love the way he teaches, how he anticipates future content, let’s viewers know there is a reason for doing something, his enthusiasm.

    • @psloh
      @psloh 5 ปีที่แล้ว +1

      Thank you for sharing your thoughts! Math is about reasoning, not about memorizing. Everything in math can be taught in a way which illuminates the reasons. :)

    • @belmer73
      @belmer73 5 ปีที่แล้ว +1

      Po-Shen Loh yes! It’s no good to just memorize. That will be quickly lost. But the ability to explain your way through a concept gives access to so much more.

    • @psloh
      @psloh 5 ปีที่แล้ว

      @@belmer73 :)

  • @Mr_Academic98
    @Mr_Academic98 5 ปีที่แล้ว +583

    That is the easiest method I have ever used. I can't imagine that I did not know this before. Thank you sir

    • @luzianleser
      @luzianleser 5 ปีที่แล้ว +7

      Google PQ

    • @DominicanOps
      @DominicanOps 5 ปีที่แล้ว +4

      I think the Colombian Method is easier to be honest.

    •  5 ปีที่แล้ว +3

      DominicanOps what Is the colombian method?

    • @أبتجده
      @أبتجده 5 ปีที่แล้ว +3

      @
      th-cam.com/video/jcRW2R42azE/w-d-xo.html

    • @theunseenblade5897
      @theunseenblade5897 5 ปีที่แล้ว +3

      th-cam.com/video/tRblwTsX6hQ/w-d-xo.html
      TH-camrs discovered it years ago

  • @nagzul1
    @nagzul1 ปีที่แล้ว +2

    I actually watched the 40:05 minute video without skipping!😂 Just like learning golf, when you can connect with the instructor through the way the knowledge is properly conveyed, then you find gold at the end of the rainbow!🎉😊

  • @laurenbrock5056
    @laurenbrock5056 2 ปีที่แล้ว +4

    This was amazing! I actually had to pause the video and derive the quadratic formula because I was so excited about noticing how it relates to this method. As soon as I finished I unpaused the video and Professor Loh started talking about how to use the method to derive the quadratic formula. The logical pathway is so satisfying in this video and I am grateful to finally understand the quadratic formula!

    • @success687
      @success687 2 ปีที่แล้ว

      Hi....

    • @Corazonlatino1995
      @Corazonlatino1995 2 หลายเดือนก่อน

      Hi Lauren and you done it at last?😉

  • @aditijaiswar4209
    @aditijaiswar4209 3 ปีที่แล้ว +1

    All indians must have studied it.. It's called Shree Dhara Acharya formula. But this is the first time i have understood the essence of the formula. That's why it's imp to understand the proof of a formula or how a formula came..this may make students buildup an interest in Mathematics. Loved it👏

  • @ericooltrips
    @ericooltrips 5 ปีที่แล้ว +3

    Po-Shen Loh's enthusiasm is the best of the video

  • @raselalafaele4527
    @raselalafaele4527 3 ปีที่แล้ว +2

    thanks Po-Shen Loh, I never studied this method in school or in University but I'm so thankful for sharing your knowledge and understanding of different methods to solve quadratic equations. I prefer learning this method for all students to know is the best choice than the normal way. Glad how you ended up connecting or even linking to the Quadratic Formula itself.

  • @MichaelBuck
    @MichaelBuck 2 ปีที่แล้ว +11

    Mind Blown! Genious! Not just in the solution but in the expert EXPLAINATION, very clear and understandable, just amazing! Thank you for taking the time to produce this video. I will go over it several times to make sure I understand its simplicity. I am now a follower and will look over your other videos. Wow, just amazing how ancient secrets from hundreds and thousands of years ago are lost over time but come back to life. I wonder how many other things are like this?

  • @kathygedamke2167
    @kathygedamke2167 2 ปีที่แล้ว

    He's actually "completing the square"! Throw the constant on the other side as a negative, take half of b, square that and add it to the number on the other side. Then you take plus or minus the square root, then add the number from the left side.
    I was actually thinking along those lines a few weeks ago, but didn't have time to follow it through. Hats off to you!

  • @kirilkirilov6241
    @kirilkirilov6241 4 ปีที่แล้ว +3

    Great method! It's so rare you see an improvement over such a basic thing as quadratic equations. I just love your enthusiasm. Science Alert brought me here.

  • @albertpost9776
    @albertpost9776 3 ปีที่แล้ว

    Genius! Why did we not learn this method at school seeing it has been known for hundreds of years. If we had more of these techniques in math classes there would be a greater interest in mathematics and more people will pursue mathematics as a career.

  • @fyradur
    @fyradur 5 ปีที่แล้ว +51

    Damn I've never been able to solve quadratic equations with irrational solutions purely in my head but now I can.

    • @aaditrangnekar
      @aaditrangnekar 3 ปีที่แล้ว +5

      Do your work and find some podophiles not quadratic lol

    • @part4963
      @part4963 3 ปีที่แล้ว +1

      @@aaditrangnekar lmao

  • @arshhasan2985
    @arshhasan2985 3 ปีที่แล้ว +2

    This is the first thing our teacher taught us to use and never waste time!

    • @JS-yg7fy
      @JS-yg7fy 3 ปีที่แล้ว

      I was taught this, since class 8 in India.

  • @-unnamed-2652
    @-unnamed-2652 3 ปีที่แล้ว +4

    This is actually the pq-Formula, but i never understood how it came to live. Thank you for this illuminating explaination.

  • @senthilkr1970
    @senthilkr1970 ปีที่แล้ว +1

    Very interesting and amazingly explained. never imagined i should have seen this 40 min continously without stopping. Great. Love to learn more.

  • @keinKlarname
    @keinKlarname 4 ปีที่แล้ว +7

    You're such a friendly person! It's a pleasure to follow your explanations, Mr. Loh.

  • @july4cat
    @july4cat 4 ปีที่แล้ว +2

    I'm a little surprised that this is considered a novel thing in the US. I learned this as the "standard" method for solving quadratic equations in junior high in China. But Prof. Loh still kept me engaged. Great professor!

    • @perpetuallyconfused2508
      @perpetuallyconfused2508 3 ปีที่แล้ว

      we did this thing called the quadratic formula that enabled us to solve any quadratic equation in Hong Kong.
      if i remember correctly, it was (-b+/-(b^2-4ac)^1/2)/2a
      if u do manage to remember it, solving quadratic equations is quite simple as well

  • @adamholub6436
    @adamholub6436 4 ปีที่แล้ว +5

    I am from Czech republic and I know this since elementary school. It's one of the taught methods to solve cuadratic ecuations.

  • @JustinGarfield1
    @JustinGarfield1 4 ปีที่แล้ว

    I know three ways so far:
    Using Quadratic formulas
    Sum of squares (yuck)
    The "x factor" don't know the technical term
    Now I got another way...ok, I am tired lol and thankful at the same time.
    You are amazing to find another way. You are a real jewel.

  • @KarmaIsEternal
    @KarmaIsEternal 5 ปีที่แล้ว +68

    This man is a LEGEND!

    • @creativeclub2023
      @creativeclub2023 4 ปีที่แล้ว +2

      The Indian mathematician Brahmagupta (597-668 AD) explicitly described the quadratic formula in his treatise Brāhmasphuṭasiddhānta published in 628 AD,[24] but written in words instead of symbols.[25] His solution of the quadratic equation ax2 + bx = c was as follows: "To the absolute number multiplied by four times the [coefficient of the] square, add the square of the [coefficient of the] middle term; the square root of the same, less the [coefficient of the] middle term, being divided by twice the [coefficient of the] square is the value."

    • @zykorplayz7618
      @zykorplayz7618 4 ปีที่แล้ว +6

      @@creativeclub2023 stfu

  • @jaedavas3050
    @jaedavas3050 4 ปีที่แล้ว +1

    Love this clever use of dimension reduction. A = x + y -> A = (A/2 + u) + (A/2 - u). I also found a fun little generalization: If A = Sum ( x_i ) for i = 1, 2, ... , N then let x_i = (1/N)A + iu for i < N and x_N = (1 / N)A - ((N - 1)N / 2)u. One number is the counterweight and the rest are various multiples of u.

    • @gerbil61
      @gerbil61 2 ปีที่แล้ว

      Are you suggesting that this can be used to factorise cubics (N=3) and higher order polynomials? If so, then how does your method work? If not, then what is this a "generalisation" of?

  • @forsadaqah183
    @forsadaqah183 5 ปีที่แล้ว +10

    Teachers like you and my best maths teachers(Chandan Sir,Azizul Sir)really inspire the students to discover and love the maths.Much respect to every good and ideal teachers.

  • @esifohawkins4697
    @esifohawkins4697 ปีที่แล้ว +1

    I like your teaching style. you actually explained how you arrived at a number which a lot of people don't do. Bravo!!!

  • @alifmusyaffa9666
    @alifmusyaffa9666 2 ปีที่แล้ว +3

    I can't believe that im finished watching this video, its amazing how Mr. PO makes math looks very interesting. Respect ❤️

  • @WoolyCow
    @WoolyCow 2 ปีที่แล้ว +1

    more people need this in their lives

  • @annakairema6774
    @annakairema6774 4 ปีที่แล้ว +4

    Many thanks for this video! It gave me (and my high school students) new insight into understanding the cubic equation formula which uses the same beautiful ideas explained so well in this video. It never crossed my mind to use these ideas to solve the simpler quadratic equation. So, thank you! Best regards, Anna/Helsinki/Finland

  • @DescendantsOfEnoch
    @DescendantsOfEnoch 5 ปีที่แล้ว +1

    Po-Shen Loh, I know you are deservingly happy discovering that we can find quadratic roots much simpler by combining these two ancient insights, BUT have you taken the time yet to notice the other side of what you have discovered? A new insight. Yes, the roots do exist but you have more importantly shown that the average of the roots also ALWAYS EXISTS! And we now see a new and strange average of the roots for an equation like x^2 -2x+3 for example yet see similarities of the root averages of X^2 +1 and horizontal translation of it like x^2 -2x +2. This is the new Loh insight of complex root averages and/or complex averages in general.

  • @alisharif3827
    @alisharif3827 4 ปีที่แล้ว +5

    Thank you for your fantastic teaching skills. I'm very happy with your lessons, because it's so easy, but I don't know why they don't teach us in College like this beautiful way. Thanks a lot.

  • @the_dreams_hashira
    @the_dreams_hashira 5 ปีที่แล้ว +2

    Even student should have a teacher like him.

  • @odinmandu2184
    @odinmandu2184 5 ปีที่แล้ว +5

    What have I been learning all my life🙆🏾‍♀️🙆🏾‍♀️
    This is beautiful 🔥🔥🔥

  • @jensimaster
    @jensimaster 3 ปีที่แล้ว +1

    This is amazing, I am watching your videos to see if they'd be a good resource for my son who's 14, but you just taught a 43 year old engineer something new! Thank you!

  • @mystiseed9443
    @mystiseed9443 4 ปีที่แล้ว +13

    I have just one word for this "AWESOME"

  • @klong4128
    @klong4128 4 ปีที่แล้ว

    Very good alternative non-Guessing method for absolute Beginner. But for those exprienced people, they just look at the quadratic Ax^2 + Bx + C = 0 , immediately write out the answer within split of second before the standard formula appearing inside their mind/brain ! This is human autoreflexive actuon through repeative practicals/failures . Action is faster than the Thinking mind. It is just like Chinese Primary School that everyone must memorised 9 x 9 or 12 x 12 multiply tables! after you left Prinary school and seldom use the multiplication tabkes for 10 yrs ,20 yrs ,50 yrs .Your mind already forget all the multiplications .But whenever somebody said A X B ! You immediately give the Result Faster than your mind thinking by Instingct ! I still prefer your alternative technique when teaching Beginners/Layman ! GOOD job keep it up .

  • @ayushmansharma4362
    @ayushmansharma4362 5 ปีที่แล้ว +9

    Thank you very much sir for this wonderful method. I m an indian JEE ASPIRANT and even i m very thankful for this method.
    I really going to share it with my friends.

    • @anshumanagrawal346
      @anshumanagrawal346 5 ปีที่แล้ว

      But Isn't It Just Completing The Square?

    • @ayushmansharma4362
      @ayushmansharma4362 5 ปีที่แล้ว

      @@anshumanagrawal346 it will come in handy for tricky quartic quadratic equations

    • @anshumanagrawal346
      @anshumanagrawal346 5 ปีที่แล้ว

      @@ayushmansharma4362 oh ok thanks

  • @pcmb6422
    @pcmb6422 4 ปีที่แล้ว

    I am from India and these type of mathematics are taught to a eight standard students but I liked the lesson great job

  • @balagopalm5995
    @balagopalm5995 4 ปีที่แล้ว +6

    Thank you sir. It's a brilliant way of solving quadratic equations rather than memorising the quadratic formula. Hoping for you to come up with many other tricks to simplify Math

  • @pj_33
    @pj_33 5 ปีที่แล้ว +1

    In 23:24 why did you take product and sun to be negative. I didn't quite get that. Because in other cases you took positive??

    • @parisfraser1609
      @parisfraser1609 3 หลายเดือนก่อน

      Need to know facts about the roots of equations sum of roots=-b

  • @ksamsati5254
    @ksamsati5254 4 ปีที่แล้ว +3

    What clarity, elegance & humility. Thank you.

  • @moinmalik1320
    @moinmalik1320 4 ปีที่แล้ว +1

    Dr. Loh: The technique of completing the square and its formal form, the quadratic formula, are beautifully re-interpreted to present an easy to handle method. Will always love to tell my students this method, giving your reference (Dr Poh-Shen Loh) and encouraging them to watch on the TH-cam.

  • @nicolealfonso5225
    @nicolealfonso5225 4 ปีที่แล้ว +3

    Thank you so much! I'm studying for the GMAT right now and this method is going to help me work through quant problems involving quadratic equations much more quickly and efficiently!!

  • @doodelay
    @doodelay 2 ปีที่แล้ว +1

    Awesome method! I am physics student and even though I am very familiar with quadratics I always find the quadratic equation and factoring very tedious!
    Your method is much faster.

  • @4theTruthseeker
    @4theTruthseeker 3 ปีที่แล้ว +4

    Seeing this.. i feel like im recovering from my illness... So unreal.. thank you professor.

  • @jonah8004
    @jonah8004 3 ปีที่แล้ว

    This is an elegant way to do the quadratic formula in a step by step way without memorization (thus more intuitive and clear about the logic).

  • @reidbarnes5579
    @reidbarnes5579 5 ปีที่แล้ว +7

    I believe the key to learning this math in general lies in understanding the relationship between the numbers and lines and the points of a line-being able to better see the graph with your minds eye so to speak. Often, too little emphasis is placed on concepts while too much emphasis is placed on finding the answer to problems, i.e. what is the answer to this one, x^2 + x + 1 = 0?, now what about this one, x^2 + 2x + 3 = 0?, now here are ten more problems for your homework.
    The advantage of Dr. Loh’s discovery is that it removes the need to recall the quadratic equation, used by high school students studying algebra. The discovery employs principles of geometry, such as that every segment has a midpoint, which frees the student to focus more on basic principles and concepts and the relationship between numbers and lines and the points of a line, rather than the quadratic formula itself.
    Lets look at some of the underlying assumptions. As for the example that every segment has a midpoint, that every segment can be bisected was Euclid’s Proposition 10. However, note that Euclid made a tacit assumption in his proof of Proposition 10 that caused Wikipedia to wrongly state that Euclidean and non-Euclidean geometry share as many as 28 of Euclid’s elementary geometry propositions, when the number is fewer than 10. See the Facebook Note, Wikipedia Contradicted by Euclid's Proposition 10, Youngsters with Ruler and Compass facebook.com/notes/reid-barnes/wikipedia-contradicted-by-euclids-proposition-10-youngsters-with-ruler-and-compa/577085739010671/.
    Also assumed is the basics of the coordinate system. Along these lines, the following is from the Yahoo article by Caroline Delbert about Dr. Loh's discovery: "Since a line crosses just once through any particular latitude or longitude, its solution is just one value."
    This statement depends on Hilbert's Axiom I. 2, that two such lines cannot share the same pair of points.
    When David Hilbert added a coordinate line, the line with the features to comprise a number line, to Euclid’s geometry, the very earliest axioms required subtle modifications. From Euclid's to draw a line from one point to any other, and extend it in a straight line, Hilbert first produced, two points determine a line and added, they determine it completely. But this eventually became every pair of points is in some line (Axiom I. 1) and two different lines cannot contain the same pair of points (Axiom I. 2, paraphrased). This 'line' is what became a coordinate line.
    The term "line" in Axiom I. 2 is an elementary term, which means it has no definition that is used in a proof. Non-Euclidean geometry depends on the stipulation that its term for "line" is an elementary term and therefore has no definition that is used in a proof. So this opens the door to interpreting the meaning of what is meant by the elementary terms, "line" or "plane," and then applying the logic of the geometry axioms.
    One type of non-Euclidean geometry says, there are no parallel lines. Well, if the “lines” are the great circles on the surface of a sphere, and the surface is their “plane,” then there are no parallel “lines” because great circles on the same sphere always intersect. (Parallel lines are defined as “lines” in the same “plane” that do not intersect.) Euclidean geometry says, through a point not on a “line” there is only one parallel to the line. When you interpret the “line” as a straight line, this seems right.
    So given an undefined line, the Euclidean geometry and non-Euclidean were seen as both logically consistent (just not logically consistent with each other). But what has been forgotten is that the non-Euclidean geometry with no parallels (called Riemannian geometry) is not logically compatible with the elementary axioms necessary for including coordinates in the geometry, such as Hilbert's Axiom I. 2. Given this inclusion, the non-Euclidean geometry then becomes self-contradicting because you can prove there are parallel lines, which contradicts the assumption that there are no parallel lines. This is described in a brief Facebook Note: Self-Contradicting Non-Euclidean Geometry facebook.com/notes/reid-barnes/self-contradicting-non-euclidean-geometry/766736476712262/

    • @balwan4679
      @balwan4679 5 ปีที่แล้ว

      Reid Barnes The relationship between Euclidean and Non-Euclidean is similar to Physics and Quantum Physics. The latter one requires a better understanding and approach.

    • @temperedwell6295
      @temperedwell6295 5 ปีที่แล้ว

      Reid Barnes, what amazing insight you have. Who would have thought that one has to invoke Hilbert's axioms and non-euclidean geometry to complete the square to solve an algebra problem?

  • @chinli72
    @chinli72 2 ปีที่แล้ว +2

    This method is so much simpler than what I was taught. Bravo Prof. Loh!

  • @capheny368
    @capheny368 4 ปีที่แล้ว +198

    I was just curious about the name of this method.
    shall we call it the Po-Shen law
    as the title of your name professor

    • @psloh
      @psloh 4 ปีที่แล้ว +43

      You're welcome to call it whatever you wish! To help people quickly identify the method, you are welcome to mention my name because then the Internet searches will quickly turn it up. :)

    • @rukmaniranganathan8420
      @rukmaniranganathan8420 4 ปีที่แล้ว +7

      Super name

    • @cursebr2937
      @cursebr2937 4 ปีที่แล้ว +1

      Nope

    • @ehsaanulhaque1857
      @ehsaanulhaque1857 4 ปีที่แล้ว +3

      Po-Shen Loh fake.

    • @creativeclub2023
      @creativeclub2023 4 ปีที่แล้ว +7

      The Indian mathematician Brahmagupta (597-668 AD) explicitly described the quadratic formula in his treatise Brāhmasphuṭasiddhānta published in 628 AD,[24] but written in words instead of symbols.[25] His solution of the quadratic equation ax2 + bx = c was as follows: "To the absolute number multiplied by four times the [coefficient of the] square, add the square of the [coefficient of the] middle term; the square root of the same, less the [coefficient of the] middle term, being divided by twice the [coefficient of the] square is the value."

  • @johntaylor181
    @johntaylor181 4 ปีที่แล้ว

    The brilliance of this method is only rivalled by the excellence of the presentation! WONDERFUL!!

  • @cakiilunicorn7929
    @cakiilunicorn7929 3 ปีที่แล้ว +10

    Can't wait to find this in text books in a few years or so.

  • @Hexcede
    @Hexcede 2 ปีที่แล้ว +2

    This is really cool. You can actually use this to derive the more commonly known quadratic formula. Just keep the variables, start simplifying and rearranging, and eventually you end up with something in the exact same form as the quadratic formula. Would really love to see you show the 2c form of the quadratic formula.
    It can be easily derived with simple algebra by taking a quadratic equal to 0, subtracting `c` on both sides, and dividing by `ax + b` to get `-c/(ax + b) = x`. Then, substituting x for the quadratic formula. After simplifying, you get a new quadratic formula (which can even solve lines!) which is equivalent to the original but flipped (reciprocal) and the 2a becomes 2c.
    Additionally, the `-c/(ax + b) = x` form you might note sorta looks recursive, and you can use it to solve a whole set of simple continued fractions (e.g. the one for phi aka the golden ration, the square root of two, etc). It basically shows that quadratic equations are continued fractions too! It's very cool.
    I discovered both in my senior year of highschool.

  • @jacobhouston1655
    @jacobhouston1655 5 ปีที่แล้ว +7

    I’m going to teach this to all my peers at my community college.

  • @CoachJonBerry
    @CoachJonBerry 3 ปีที่แล้ว

    High School math teacher here! In recent years, I've preached using the "a-c"/Grouping Method to factor quadratics (and I still like it more than the other factoring methods I've taught in the past). I can see the method in this video to be a topic that would flow well AFTER a student learns the "a-c"/grouping method for two reasons... 1) For simple quadratics (especially when a=1) this method would be more time-consuming. 2) For non-accelerated math students, my experience leads me to believe that finding the sum of 'negative b' would serve as an unnecessary curve ball. Nonetheless, my Math Team kiddos should really enjoy this -- and I'm excited to present it to them this year! Great video... well done, sir!!

    • @chocolateangel8743
      @chocolateangel8743 3 ปีที่แล้ว

      I'm a visual and conceptual math learner that's been out of school for a while -- but had to re-discover math to help with homework. When I first came across this method, I found it too abstract and left like he left some things out. However, now that I UNDERSTAND it, I find it pretty simple -- and fun. Here's how I'd teach it.
      First, I would introduce the alternative form that Po uses, making sure to emphasize that the negative sign (-) is part of the new form. Secondly, I would make sure to use a graph, highlighting the fact that the "b" value is the diameter of the palabra. Thirdly, I would tell them that finding the midpoint is helpful because it allows you to jump the same distance in either direction to find the roots.
      When the kids see this on a graph, I think it will make sense to them. Oh, I also forgot to say that you should tell them this method combines the traditional method of factoring and the idea of using the midpoint of a palabra. Tell them that they are starting with the sum, and multiplying the two numbers together to equal c allows them to figure out what they need to add to the sum to make it true.
      I don't mean to tell you how to do your job, but these are the kinds of things I wondered about and had to go through a ton of videos to figure out. Oh, this also reinforces Diff. of Squares. Happy teaching.

    • @CoachJonBerry
      @CoachJonBerry 3 ปีที่แล้ว

      @@chocolateangel8743 Thanks for taking the time to reply! Since I wrote my comment, I immersed myself into coming up with a way to break this method down and introduce it to my Precalculus students who were using the ALEKS program in Algebra 2 and thus learned the "a-c Grouping Method." I've almost finished my written version of the lesson, and I plan to make a video of it next week for me to critique and see if I want to try it this year. Thank you for reminding me of the visual learner, as I'm inspired to include that in my lesson. I'll put my video on TH-cam and post the link in these comments in case you want to check it out. Take care!

    • @CoachJonBerry
      @CoachJonBerry 3 ปีที่แล้ว

      @@chocolateangel8743 I taught this lesson to two of my high school classes TODAY: th-cam.com/video/Db-8OAz9pYM/w-d-xo.html I was very pleased with the comprehension and my students' confidence to now be able to solve ANY quadratic (even those with imaginary or irrational solutions). I was also inspired by Po-Shen Loh's method, but I decided to have my students briefly investigate their factoring solutions (and look at the visual connections) to bridge the gap to the new method. Thanks!

    • @chocolateangel8743
      @chocolateangel8743 3 ปีที่แล้ว

      @@CoachJonBerry That's awesome! Since I've been researching Quadratics, I've also come across another method called the PQ formula. Asians (and some Germans) mentioned how it's also easier and quicker than the QF. It is! It's really easy to pick up and can be derived with an area model. I slightly prefer it over Professor Loh's approach: th-cam.com/video/pkaDqWRYm1c/w-d-xo.html

    • @CoachJonBerry
      @CoachJonBerry 3 ปีที่แล้ว

      @@chocolateangel8743 Thanks for the link. I have seen that video in the past, but it's definitely food for thought. I do, however, think that the way I adapted Dr. Loh's method is the most effective way I could reach my high school students. Take care!

  • @muhammedshameel5684
    @muhammedshameel5684 5 ปีที่แล้ว +148

    This is why I love mathematics, 😀😀

    • @muhammadazeem9775
      @muhammadazeem9775 4 ปีที่แล้ว +2

      th-cam.com/video/L4ImyFn1xLk/w-d-xo.html

  • @ΔημήτρηςΜπινιακου
    @ΔημήτρηςΜπινιακου 3 ปีที่แล้ว +2

    Your method should be in all high school math books.

  • @WestalSage
    @WestalSage 5 ปีที่แล้ว +9

    So in short, it's still the quadratic formula, but force A=1, then simply rewrite sqrt((B^2-4C))/2 as sqrt( (B/2)^2 - C )
    I agree that this makes it simpler, and I think the key is that you're dealing with B/2 on both sides of the plus/minus.

    • @_This_is_L_
      @_This_is_L_ 5 ปีที่แล้ว

      Nice meeting again!
      I think this vdo clears the doubt we were having with that method....

    • @vishnukumarsingh4966
      @vishnukumarsingh4966 3 ปีที่แล้ว

      This is Shridhar Acharya formula which is already there in class 9 textbooks.

  • @uplink-on-yt
    @uplink-on-yt 2 ปีที่แล้ว

    Wow. I actually stand a chance of understanding the quadratic equation now. This is building it using the most basic math possible, and explaining like I'm a 15 year old - which is how it should have been explained when I was 15.

  • @_p0tz_
    @_p0tz_ 5 ปีที่แล้ว +28

    Normal methods require quadratic formulas or completing the square.
    This method combines the two which makes it easier

    • @M.Ack11
      @M.Ack11 4 ปีที่แล้ว +1

      Splitting the middle term is also another normal method to solve Q.E

  • @devondevon3416
    @devondevon3416 2 ปีที่แล้ว

    Yes, this is an easy way to do quadratic equations and could be helpful to individuals who are fearful of math. He has been coaching the US math olympiad team for 6 years.

  • @advaitkarmarkar6937
    @advaitkarmarkar6937 5 ปีที่แล้ว +4

    Wow....exams are a breeze now
    3b1b can make an amazing animation to get this method's essence
    You deserve recognition sir

    • @Lessthanzero_
      @Lessthanzero_ 5 ปีที่แล้ว

      Nope 3B1B provide depth to mathematics. He isn't amateur

  • @ablobofgarbage
    @ablobofgarbage ปีที่แล้ว

    I'm swedish and the quadratic equation i learned in school is actually a version of this, it's called "p q formeln" (meaning the p q formula), however, we didn't learn how it worked (we just had to memorize it) and i think that this video explains it amazingly, i don't think that i will ever forget it anymore!
    edit:
    i just got to 32:50 and the equation that he wrote down is almost exactly the formula i learned except that p was used instead of B and q was used instead of C and the B^2/2 was written as (p/2)^2

  • @naurnootnoot
    @naurnootnoot 3 ปีที่แล้ว +5

    This is groundbreaking material, truly eyeopening

  • @rekhaparmar9259
    @rekhaparmar9259 3 ปีที่แล้ว +2

    The first time I had my own way started to studying because of you

  • @mathisreallyfun
    @mathisreallyfun 5 ปีที่แล้ว +10

    Amazing! Will start showing students this too! Thank you!

    • @psloh
      @psloh 5 ปีที่แล้ว +5

      Nice to connect with a fellow educator!

    • @mathisreallyfun
      @mathisreallyfun 5 ปีที่แล้ว +2

      Po-Shen Loh yes! I’m so happy when I saw your video. Really inspiring! Thank you!

  • @ramonalejano671
    @ramonalejano671 ปีที่แล้ว

    Professor Po-Shen Loh found and original insight. You are amazing!

  • @jjphenom2831
    @jjphenom2831 3 ปีที่แล้ว +13

    I am quite surprised that this has not been more widely known.
    In Germany it is called the pq-Formula (because of x^2+px+q) and it has probably been the most common way it is being taught.

    • @chocolateangel8743
      @chocolateangel8743 ปีที่แล้ว +1

      @JJPhenom I'm American. When I was in school, we were just expected to memorize the Quadratic Formula. It was never explained to us. I had never heard of the PQ Formula -- until I heard of the Po-Shen Loh method and began doing research and watching a lot of videos. I think the way the Po-Shen Loh method is presented (especially when done with a graph) makes it easier to understand & makes the formulas make sense.

    • @jjphenom2831
      @jjphenom2831 ปีที่แล้ว +1

      @@chocolateangel8743 I absolutely agree. I was only surprised that this is not necessarily the way it has been taught.

    • @chocolateangel8743
      @chocolateangel8743 ปีที่แล้ว

      @@jjphenom2831 I think it's because of how generations of math educators have been taught (at least in America). I've talked to a lot, and the idea of learning math on a deeper level, from a more conceptual perspective, is pretty new for us. Back-in-the-day, being good at math just meant that you were good at memorizing algorithms (even if you didn't understand them). Plus, the standards that teachers had to meet in order to teach math were pretty low.
      When they first raised them, many teachers that had been teaching for years, couldn't pass them. It was a big deal because they also couldn't replace all these teachers. The kids basically got screwed. These teachers were talking about how hard the tests were to pass. So, I asked some professors that had taught at the high school and college levels. They said they weren't that had -- if you understood math. If just tried to get through everything using memorization, you were in trouble.

    • @jjphenom2831
      @jjphenom2831 ปีที่แล้ว

      @@chocolateangel8743 Oh I see. That sounds like an interesting shift in approaches. I will be following up on how successful this turns out to be.
      Here the formula is often applied quite algorithmically and without going very deep into its derivision. I do not know the reason why this is the predominant method of solving quadratic equatiins though. Would be interesting to see a worldwide distribition

  • @abrahamtaloinao9382
    @abrahamtaloinao9382 3 ปีที่แล้ว

    Best teacher I have ever have.

  • @robertcastillo8157
    @robertcastillo8157 5 ปีที่แล้ว +5

    This is a great way to approach quadratic equations...great job!

  • @sanketgolhar9595
    @sanketgolhar9595 4 ปีที่แล้ว

    Very easiest method to solve quadratic equation .It is very nice method. Thank you sir...

  • @ly_lols
    @ly_lols 4 ปีที่แล้ว +3

    This is the most helpful video i've ever seen

  • @tavakoliferi1409
    @tavakoliferi1409 2 ปีที่แล้ว +1

    Excellent Méthode Monsieur Shen Loh : une solution rapide et efficace. Merci

  • @edmund6392
    @edmund6392 3 ปีที่แล้ว +3

    Showed this to my 7 year old math obsessed daughter and she immediately understood. She loves learning advanced math and we love your explanations. Thank you!

  • @arifabegummirza8515
    @arifabegummirza8515 4 ปีที่แล้ว

    A born teacher. Excellent sir.

  • @joshurlay
    @joshurlay 5 ปีที่แล้ว +7

    I think this is quite remarkable to be put into words. A lot of my family members struggle with quadratic equations and I think this will be much easier for me to teach them. To be honest, this is already kinda what I use to brute force my way through quadratic equations with very large coefficient's to impress whoever I'm tutoring at the time. This definitely takes it a step further though.

    • @pyropulseIXXI
      @pyropulseIXXI 2 ปีที่แล้ว

      You try to impress people you are tutoring..... and in just basic algebra? LMAO, that is too funny. If you want to impress the people you tutor just do what I did; I was tutoring people in the class I was also taking, and I even tutored some people in organic chemistry, and I never even took the course.
      So when my fellow students find this out, they are amazed at how I know all this stuff, "Even better than the teacher!" That is true impressments

  • @SuccessTeamEngineeringDesign
    @SuccessTeamEngineeringDesign 4 ปีที่แล้ว +2

    This is very helpful. Thank you Dr. Po Shen Loh for expounding our knowledge of maths in a precise way of Reasoning without guessing.

  • @trevorallen3212
    @trevorallen3212 4 ปีที่แล้ว +3

    Finally I can put factoring aside it's lot more harder guessing than not having to deal with it.

    • @chocolateangel8743
      @chocolateangel8743 3 ปีที่แล้ว

      This method actually combines factoring with an understanding of palabras (the midpoint, in particular). Once you understand it, I do think it's easier. However, it works better on some problems than others. If there's a leading coefficient other than one and you have to deal with lots of fractions, things get can get messy.

  • @fleetwoodray
    @fleetwoodray 4 ปีที่แล้ว +1

    Last time I solved for any quadratic equations was over 30 yrs ago. Nice to see it being solved differently than the "establishment" way.

  • @dlu0813
    @dlu0813 5 ปีที่แล้ว +7

    Thanks Mr. Loh! You're a great help to my math career and I can't wait to see more challenge videos! :)

    • @psloh
      @psloh 5 ปีที่แล้ว +2

      Pleasure to share this one with everyone!

    • @dududaud.4221
      @dududaud.4221 5 ปีที่แล้ว

      Yes..... He is a genius...
      Thanks Dr.
      I love Mathematics my favourite

    • @academia1798
      @academia1798 5 ปีที่แล้ว

      Sir your content is highly discussed by Triangular Kamal which is really easy for all kinds of people.
      th-cam.com/video/CMNDwY7q7AU/w-d-xo.html

  • @hyekyungkim6850
    @hyekyungkim6850 4 ปีที่แล้ว +2

    He is the BEST teacher ever! I loved how he teaching way. Thank you!!