Approximations. The engineering way.

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  • čas přidán 4. 04. 2021
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Komentáře • 521

  • @Hempujonsito
    @Hempujonsito Před 3 lety +1015

    "for calculation purposes, let asume this cow is perfectly round"

    • @thepiratepeter4630
      @thepiratepeter4630 Před 3 lety +59

      @@danielyuan9862 Considering the digestive system, isn't a cow more related to a donut?

    • @lucaokino6776
      @lucaokino6776 Před 2 lety +24

      let’s assume this cat is a cube

    • @sleepycritical6950
      @sleepycritical6950 Před 2 lety +6

      @@thepiratepeter4630 but aren't there more than one orifice?

    • @thepiratepeter4630
      @thepiratepeter4630 Před 2 lety +1

      @@sleepycritical6950 But the other orifices aren't "tubes"

    • @sleepycritical6950
      @sleepycritical6950 Před 2 lety

      @@thepiratepeter4630 still counted. A sphere with a hole is no longer a sphere. A torus with a hole on the surface is also not a torus.

  • @user-uu5xf5xc2b
    @user-uu5xf5xc2b Před 3 lety +426

    I'm an engineer
    I see approximation
    I click

  • @Nylspider
    @Nylspider Před 3 lety +936

    "Approximations"
    Oh cool
    "The Engineering way"
    _oh boi this is gonna be good_

    • @blankblank9621
      @blankblank9621 Před 3 lety

      Google Play Store Search : jumpjump

    • @blankblank9621
      @blankblank9621 Před 3 lety

      Fun And Surprising Game is here.

    • @blankblank9621
      @blankblank9621 Před 3 lety +1

      playtime is short but,

    • @blankblank9621
      @blankblank9621 Před 3 lety

      only 1 dollar cost is snack cost. This Is Jump Game Adventure. Great BGM And GRAPHIC Is In the Game. Please Enjoy. jumpjump game is Fun.

    • @blankblank9621
      @blankblank9621 Před 3 lety

      Thank you

  • @RC32Smiths01
    @RC32Smiths01 Před 3 lety +80

    "Why be right when you can approximate?"

    • @livedandletdie
      @livedandletdie Před 3 lety +10

      Why get a girlfriend when you can get a proxy mate.

  • @JTCano42
    @JTCano42 Před 3 lety +107

    The Forbidden Math

  • @rentristandelacruz
    @rentristandelacruz Před 3 lety +268

    I'm only at 0:16 and I'm already having numerical computing class flashbacks (took that class ten years ago). Netwon Raphson, Regula Falsi, Runge-Kutta. It's all coming back.

  • @kazuhoshiinoue2695
    @kazuhoshiinoue2695 Před 3 lety +393

    Mathematicians: We need exact solutions!
    Engineers: Nah, "close enough" is good enough.

    • @billferner6741
      @billferner6741 Před 2 lety +12

      Right! We first determined what percentage is acceptable, then we stopped iterating. Btw, they went to the moon with calculating with a slide ruler, only 3 decimals, with estimation, 4.

    • @justyourfriendlyneighborho903
      @justyourfriendlyneighborho903 Před 11 měsíci +2

      But those numbers are irrational, we will never have an exact solution, the estimation becomes synonymous with the exact value for any actual application and for anything abstract we just keep it as is, sqrt(a)

    • @DaTimmeh
      @DaTimmeh Před měsícem

      Applied Mathematicians: We need to get exactly close enough!

  • @adityachk2002
    @adityachk2002 Před 3 lety +224

    Math never fails to surprise me, I could not even think such a thing could exist

    • @Simpson17866
      @Simpson17866 Před 2 měsíci

      The original special case for square roots is called "The Babylonian Method" because it was invented by a Greek mathematician living in Egypt.
      I think it was named by an engineer who decided "Greece and Egypt ≈ Babylon"

  • @theoreticalphysics3644
    @theoreticalphysics3644 Před 3 lety +626

    Ah, the fundamental theorem of engineering.

    • @Ryanisthere
      @Ryanisthere Před 3 lety +60

      2 = e = π =3
      this is the first thing you learn in engineering college

    • @vendettaanonimous5545
      @vendettaanonimous5545 Před 3 lety +2

      @@Ryanisthere haahhahahhahhahha awesome😁😁😁😂😂😂 engineer for ever😎😎😎

    • @vendettaanonimous5545
      @vendettaanonimous5545 Před 3 lety +15

      and sin(x) = x 😂😂

    • @black_jack_meghav
      @black_jack_meghav Před 3 lety +8

      @@Ryanisthere i don't quite get these jokes. Aren't engineers got to be precise so that buildings don't fall off and circuits don't burn? Using pi=3 would be a fukin travesty, right?

    • @Ryanisthere
      @Ryanisthere Před 3 lety +3

      @@black_jack_meghav r/woooosh

  • @Cralcker
    @Cralcker Před 3 lety +118

    We’re doing this in my calc class rn and I swear to god you explain it better than my professors

  • @aenesturan
    @aenesturan Před 3 lety +78

    first law of engineering: everything is linear

  • @davidbeckham2715
    @davidbeckham2715 Před 3 lety +79

    Please keep making these so I can make it through college.

  • @PapaFlammy69
    @PapaFlammy69 Před 3 lety +577

    Nice Clock and Watch, where can I get one of deeze, Zach? :^D

  • @rbpict5282
    @rbpict5282 Před 3 lety +50

    That's a really cool formula

  • @iangolsby8471
    @iangolsby8471 Před 3 lety +28

    That square root approximation is elegantly simple. Each guess is just the average of the previous guess, and the number over that previous guess. As you approach the root, it becomes the average of the root and the number over the root (number over root is the root). So beautiful

  • @mastershooter64
    @mastershooter64 Před 3 lety +17

    dude I was just expecting to get some stuff like pi = 3 = 3 or g^2 = 10 or something like that, but I actually learned a lot!

  • @foxtrot8325
    @foxtrot8325 Před 3 lety +17

    Zach : It's possible to get stuck in an infinite loop.
    Float error : IT'S MY TIME TO SHINE

  • @benthayermath
    @benthayermath Před 3 lety +15

    We ❤ approximations!
    Honestly, sometimes wanting an exact solution is lazy. People don't realize how much math goes into designing numerical methods and proving their convergence and stability.

    • @bobh6728
      @bobh6728 Před 2 lety +1

      Most square roots can only be approximations since they are irrational. There is no exact solution unless you write with the square root symbol. If you want to use just digits it is going to an approximation. To anyone who says “just use a calculator”, guess what? The calculator uses an algorithm to find the square root up to the number of digits the calculator can work with.

  • @kyrond
    @kyrond Před 3 lety +19

    I did a Bachelors thesis partly on this, when I finally got how it worked when I saw it, it was almost magical.

  • @jacktorborg9862
    @jacktorborg9862 Před 3 lety +15

    I had to use the newton raphson method in my engineering career a few years ago to approximate a function (solving a Civil Engineering equation backwards with multiple square roots in weird places) that otherwise converges on a few nonreal/negative answers and one real, positive one I was looking for. I never thought I would actually apply it in my life when I learned it, but it felt so cool to have a real world application for it! Made me realize that weird, theoretical math part of my degree wasn't quite such a waste of time after all!

  • @billferner6741
    @billferner6741 Před 2 lety +6

    Interesting topic! This reminds me on programming in BASIC interpreter 40 years ago. At that time the value of PI was not implemented, the solution was : 4*arctan(1), which gave PI with the accuracy of devise's BASIC.

  • @braxtonclaflin1818
    @braxtonclaflin1818 Před 3 lety +14

    We’re literally on this exact topic in calculus right now

  • @FranzBiscuit
    @FranzBiscuit Před 3 lety +3

    The effort put into these videos is just amazing. And the educational content, truly first class. Keep up the good work Zach!

  • @sameerkamath1239
    @sameerkamath1239 Před 3 lety +3

    Really cool to see these real world applications- the way you teach math makes it fun and interesting!

  • @machinedgod
    @machinedgod Před 3 lety +4

    Quickly becoming my favorite youtube channel!

  • @EmperorSaistone
    @EmperorSaistone Před 3 lety

    Absolutely beautiful. I learned that stuff year ago at the university, but you described it so so much better.

  • @ssquarkgaming1405
    @ssquarkgaming1405 Před rokem +3

    What a great video 👌
    It would have been such a great starting point for me a while back when I was writing GPU algorithms for fast square and cube roots of float 32 and float 64 values.
    Managed to get them super fast combining Taylor series expansions, the power laws and the good old Newton raphson iteration. If I remember correctly, about 3ns to compute cube root to fp64 precision.

  • @moncefkarimaitbelkacem1918
    @moncefkarimaitbelkacem1918 Před 3 lety +12

    quality content
    as always

  • @AmitKumar-xw5gp
    @AmitKumar-xw5gp Před 3 lety +2

    Very awesome video Zack.. Keep up the good work..

  • @gastonhebert9967
    @gastonhebert9967 Před 3 lety

    Doing it at engineering school, and very happy to find it on CZcams ! Thanks

  • @C0MPLEXITY
    @C0MPLEXITY Před 3 lety

    Thanks a lot for the amazing info dude, it's satisfying to get stuff explained by you

  • @shrideepgaddad8721
    @shrideepgaddad8721 Před 3 lety +4

    Holy crap thanks for explaining this, the random pdfs that I found on the internet are confusing as hell.

  • @MrMoore0312
    @MrMoore0312 Před 3 lety

    Thanks for the timely video and inspiration! Just finished related rates in Stewart's calculus and the literal next section is linear approximations. Loved this video and can't wait to be thoroughly confused by that coming numerical analysis video lol

  • @caelank5544
    @caelank5544 Před 3 lety

    This is so incredibly helpful. I literally had a numerical analysis assignment last week where we had to use Newton Raphson

  • @davidhicks8290
    @davidhicks8290 Před 3 lety +2

    Numerical analysis is the coolest class of functions that have already been written for you

  • @vincentdavis8960
    @vincentdavis8960 Před 3 lety +1

    Great video! I was wondering if you would mention the Quake fast inverse square root and then bam! Awesome. Keep up the great work!

  • @ArmaanDK
    @ArmaanDK Před rokem

    Thank you for bringing context to an otherwise "insignificant" topic covered for 15 mins in a first year calculus course! I thought I hated math, but I've just been missing out on how much fun it can be once you wrap your head around the concepts

  • @kairostimeYT
    @kairostimeYT Před 3 lety +16

    Applied Numerical Methods. I don't remember the exact name but I remember a technique which converts a definite integral to two (or natural number) terms. Gauss quadrature rule, was it? I honestly was intrigued by this method.

  • @Lunamana
    @Lunamana Před 3 lety +2

    I have a Numerical Analysis midterm in 8 hours so i clicked on this as soon as i saw it in my sub box, thanks ^^

  • @iGR8soccer
    @iGR8soccer Před 3 lety +1

    could have used this video last semester during numerical methods. you explained it better in 14 minutes than my prof did in 3 lectures

  • @Pedritox0953
    @Pedritox0953 Před 3 lety +1

    Awesome video!

  • @daviddabeegukabassima8232
    @daviddabeegukabassima8232 Před 10 měsíci

    As an Engineer I relate to these useful approximations. Thank you so much for theses examples and explanations!

  • @tomcarroll6744
    @tomcarroll6744 Před 10 měsíci

    Good stuff. Nice job.

  • @feuerrm
    @feuerrm Před 3 lety +1

    Looking forward to a video about Numerical Analysis, I'm taking it in the fall!

  • @justinmccoy4270
    @justinmccoy4270 Před 3 lety +2

    The quake 3 fast inverse square root video got me into watching these kinds of videos. Now that's a meme you'll want to see.

  • @FromLake
    @FromLake Před rokem

    Thank you very much for this video.

  • @TheDecooledaan
    @TheDecooledaan Před 3 lety +1

    Great timing. I'm starting my numerical analysis class at uni tomorrow

  • @rajbunsha8834
    @rajbunsha8834 Před 3 lety

    I heard about it before but was thinking why isn't it too famous thanks for elaborating it. I always wanted to know more about it keep it up😀😀😀👍👍🙏🙏

  • @Listener970
    @Listener970 Před 3 lety

    Beautiful!

  • @TylinaVespart
    @TylinaVespart Před 3 lety

    Damn it's been ages since I did maths "properly", but this was really accessible and a good reminder of how it all slots together. Thank you!

  • @patrickforsyth9880
    @patrickforsyth9880 Před 3 lety

    great vid as always

  • @udaysrivastava1957
    @udaysrivastava1957 Před 3 lety

    Please make videos like this.
    It was a wonderful video.

  • @sunnohh
    @sunnohh Před 3 lety

    That was one of the coolest videos about a table on my calculus book that I took as magic

  • @dylgir1332
    @dylgir1332 Před 3 lety

    Yas! You posted something on your OG profile! LIT 🔥

  • @AdityaKumar-ij5ok
    @AdityaKumar-ij5ok Před 3 lety +1

    Everyone in comments section: it was about time that you decided to finally make a video this

  • @LaserFur
    @LaserFur Před 3 lety +2

    long ago I wrote a integer Square root on a DSP processor. It used the DSP's single cycle multiplier to create the square. then it compared it and set one output bit. after 16 loops I had a 16 bit result.

  • @tommyhuffman7499
    @tommyhuffman7499 Před 3 lety

    Very cool video!!

  • @matthewao
    @matthewao Před 3 lety +3

    approximations the engineering way: 𝝅=e=3, g=10m/s²=9=𝝅²=e²

  • @mahdialhassan6802
    @mahdialhassan6802 Před 2 lety

    Dude, I really have to watch all your videos about engineering’s stuff. im in my second year and there is a lot of things i have to be familiar with

  • @clastastic
    @clastastic Před 3 lety

    I read this under the heading computational methods
    TODAY!!

  • @jessstuart7495
    @jessstuart7495 Před 3 lety +1

    Chebyshev Approximations are also very useful.

  • @bittubabu4178
    @bittubabu4178 Před 2 lety

    ooh boi i am going through these in my current semester and already coded the fn for iterattive method and newton raphson, loved to know more on it😊

  • @rubenlarochelle1881
    @rubenlarochelle1881 Před 3 lety +1

    0:00 I've been studying and practicing English for the last 22 of my 25 years of age, but only now I found out that, unlike my mother tongue, English has two separate words for clocks and watches, despite I've known and used both words for years now.

  • @Sam-he3ks
    @Sam-he3ks Před 3 lety

    You should definitely talk about the finite element method. Approximating differential equations is a huge deal in engineering (especially civil/mechanical/aerospace)

  • @CellarDoor-rt8tt
    @CellarDoor-rt8tt Před 3 lety

    Just to contribute an interesting point here. Arguably the most significant piece of evidence we have when it comes the global regularity problem for the Navier Stokes equations is Terence Tao’s work on the subject. His biggest paper on the subject showed that for an approximated form of the Navier Stokes equations (one that has been averaged in an extremely specific and accurate way) blow up results occur.
    The relevance of this is two fold
    1. This may very well be one of if not the most complicated approximations ever thereby showing how approximations are an important part of math and science at every level
    And 2. It shows that even pure mathematicians can use approximations to create partial progress on the toughest problems ever. That result was huge as it showed both that there is a possible pathway toward a full solution and it also showed that any attempt at proving global regularity in the positive would require methods which delve into the finer nonlinear structures with the full pde that got averaged out in the approximation. In many ways, this paper is why most of the community believes that global regularity for Navier Stokes is going to be solved in the negative whenever it happens.

  • @MusiXificati0n
    @MusiXificati0n Před 3 lety

    This video would have been glorious half a year ago... Had a University course in evolutionary game theory and literally all of it was linear approximation because biological/evolutionary models are only estimations and I did not understand what a fixed point was. Seems so easy now...
    Thanks a lot!

  • @slartbarg
    @slartbarg Před 3 lety +5

    Numerical Methods was one of the more rigorous and work-intensive courses in my mechanical engineering workload so far

  • @soyokou.2810
    @soyokou.2810 Před 3 lety +1

    Diophantine approximation is a surprisingly interesting area of number theory too.

  • @marsp2691
    @marsp2691 Před 3 lety +8

    Just proof lim (xn)n=sqrt(c) but that wouldn’t be engineering style

  • @dakkadakka4036
    @dakkadakka4036 Před 3 lety

    Im currently taking a numerical analysis course right now, this 10 minute video made more sense than the whole class has this semester -.-

  • @pabloariza2295
    @pabloariza2295 Před 3 lety

    pretty cool stuff

  • @ARKGAMING
    @ARKGAMING Před 3 lety

    The clock looks awesome

  • @naswinger
    @naswinger Před 3 lety

    can't wait for the numerical analysis examples that took way longer than expected :-)

  • @juliusteo
    @juliusteo Před 3 lety +1

    I took numerical analysis in uni (I think it was called numerical methods) and they recommended to have two scientific calculators to iterate calculations more efficiently (if we're not going to bring our laptops to use excel in class)

  • @aceroadholder2185
    @aceroadholder2185 Před 3 lety +1

    Some approximations are quite good. If you use 22/7 for the value of Pi then on a 100 ft. diameter circle the circumference error is ~one and a half inches.

  • @Cyrathil
    @Cyrathil Před 3 lety

    Where was this video at the start of the semester. Could have saved me so much time trying to get the early chapters in the numerical analysis class I am taking...

  • @vjekokolic9057
    @vjekokolic9057 Před 3 lety

    11:53 both solutions of the equation are the golden ratio, but one is the longer side/shorter side and the other one is the reciprical, shorter side/longer side

  • @b1ngnx33
    @b1ngnx33 Před 3 lety

    THANK YOU.

  • @WLand10
    @WLand10 Před 2 lety

    What program do you use to make these videos? The math looks so clean, organized, and beautiful.

  • @yugdesai4140
    @yugdesai4140 Před 3 lety

    Video would have helped so much in understanding my numerical methods class if it was a year ago

  • @onstantinosameranis4674

    there are some really cool algorithms. First order methods that use only the derivative and second order methods that need fewer iterations but are damn expensive. @Zach Star Please make a video on gradient descent. Hopefully some of the my students will see the simple version and we can move directly into the more involved variants. There is plain gradient descent, smooth gradient descent, accelerated gradient descent, mirror descent, coordinate descent, BFGS and L-BFGS.

  • @joseant.santiago7216
    @joseant.santiago7216 Před 2 lety

    ¡Gracias!

  • @danieljulian4676
    @danieljulian4676 Před 3 lety

    Right after watching this video, I listened to Bob Dylan singing "Queen Jane Approximately" from "Blonde On Blonde". Dylan really sucks at rigorous explanation, and Newton-Raphson is also well-presented elsewhere ad nauseam. I understand that going beyond the basics is more difficult, which makes producing lots of videos less likely, and maybe no one will ever even look for the next steps. That is the dilemma of the youtube STEM educator, and is in large part why MIT's OCW series and similar stuff exists and is valuable. That said, it's great that you are reaching out to learners who are just starting out. Well done, man. L'chaim.

  • @JonathanMandrake
    @JonathanMandrake Před 2 lety

    Another example of numerical approximations of things that are hard to arithmetically calculate is a matrix inverse. Similar to the iteration pf the square root, there is a simple iteration process that leads to a good approximation of the matrix inverse, which takes way longer to compute than the square root, both on a camculator and by hand

  • @danielsantrikaphundo4517

    10:43 that iteration method is just computing the finite simple continued fractions of the golden ratio, and will converge to its simple continued fraction.
    A great opportunity to bring up that topic :D

  • @bryanfuentes1452
    @bryanfuentes1452 Před 3 lety

    i remember this when i took numerical method class. we used loop method to program this

  • @cesaramaro6933
    @cesaramaro6933 Před 3 lety +2

    I went through the first 4 minutes of this just thinking huh, this reminds me a lot of Newton-Rhapson that I learned last summer in Numerical Comp.

  • @user-my1bq5uw6l
    @user-my1bq5uw6l Před rokem

    amazing

  • @liamodonovan5374
    @liamodonovan5374 Před 3 lety

    would love to see a video about interpolation/extrapolation :)

  • @tedchirvasiu
    @tedchirvasiu Před 3 lety

    Awesome

  • @grimreaper173
    @grimreaper173 Před 3 lety

    A control theory and applications would be cool to control systems as well as machine learning applications also love the video applications to engineering with algorithms used in matlab and simulink modeling and simulation is such a great field!

  • @roberthuntley1090
    @roberthuntley1090 Před rokem

    One that I can remember (I picked it up from one of Clive Sinclair's companies) is that Pi to 6 decimal places is 355/113. Dates back to the early calculators of the 70s, before scientific calculators were available at affordable prices.
    BTW - 3550001/1130001 does this to 8 decimal places.

  • @user-zu1ix3yq2w
    @user-zu1ix3yq2w Před 3 lety

    This video came out approximately on my birthday

  • @DeGuerre
    @DeGuerre Před 3 lety

    The way your computer calculates square roots (assuming it's a recent computer) is using a related method, Goldschmidt's algorithm. Let Y be an approximation to sqrt(n). Set:
    x_0 = Y*n
    h_0 = Y*0.5
    And iterate:
    r_i = 0.5 - x_i * h_i
    x_{i+1} = x_i + x_i * r_i
    h_{i+1} = h_i + h_i * r_i
    Then x_i converges to sqrt(n) and y_i converges to 1/2sqrt(n). As hinted at in the video, some approximations have advantages over others. In this case, the advantage is that the "inner loop" is three copies of the same operation a + b * c, called a "fused multiply-add". This saves on circuitry compared to Newton-Raphson methods.

  • @hamzaennaji
    @hamzaennaji Před 3 lety

    Legendary

  • @nix_
    @nix_ Před 3 lety +35

    I remember doing this in maths. Just not sure if it was GCSE or A-level.
    Edit: It was A-level

  • @marklu5521
    @marklu5521 Před 2 lety +1

    Wait a minute… back in calc 1 I only learned (f(x-h) + f(x)) / hunt holy crap this brought me a whole new meaning lol

  • @thespuditron9387
    @thespuditron9387 Před 3 lety +1

    Ok, so I just tried the square root formula on excel and it is so damn satisfying.

  • @aidanokeeffe7928
    @aidanokeeffe7928 Před 3 lety +7

    Thank you for making this. A needed response to all the cringey "pi=e=3" memes!

  • @makkusaiko
    @makkusaiko Před 2 lety

    Finally, i good way of writing down Heron's method