Approximations. The engineering way.

Поделиться
HTML-код
  • Опубликовано: 4 апр 2021
  • Get the engineering clock/watch here: stemerch.com/collections/cloc...
    Engineering Shirt: stemerch.com/collections/fund...
    STEMerch Store (everything else): stemerch.com/
    Clock explanation (flammable maths video): • The Single Most Import...
    Support the Channel: / zachstar
    PayPal(one time donation): www.paypal.me/ZachStarYT
    Join this channel to get access to perks:
    / @zachstar
    ►Follow me
    Instagram: / zachstar
    Twitter: / imzachstar
    2D Graphing Software: www.desmos.com/calculator
    Thumbnail Design done by ‪@EpicMathTime‬
    Animations: Brainup Studios ( brainup.in/ )
    Check out my Spanish channel here: / zach star en español
    ►My Setup:
    Space Pictures: amzn.to/2CC4Kqj
    Magnetic Floating Globe: amzn.to/2VgPdn0
    Camera: amzn.to/2RivYu5
    Mic: amzn.to/35bKiri
    Tripod: amzn.to/2RgMTNL
    Equilibrium Tube: amzn.to/2SowDrh
    ►Check out my Amazon Store: www.amazon.com/shop/zachstar

Комментарии • 521

  • @Hempujonsito
    @Hempujonsito 3 года назад +1015

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

    • @thepiratepeter4630
      @thepiratepeter4630 3 года назад +59

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

    • @lucaokino6776
      @lucaokino6776 2 года назад +24

      let’s assume this cat is a cube

    • @sleepycritical6950
      @sleepycritical6950 2 года назад +6

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

    • @thepiratepeter4630
      @thepiratepeter4630 2 года назад +1

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

    • @sleepycritical6950
      @sleepycritical6950 2 года назад

      @@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 3 года назад +426

    I'm an engineer
    I see approximation
    I click

  • @Nylspider
    @Nylspider 3 года назад +936

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

    • @blankblank9621
      @blankblank9621 3 года назад

      Google Play Store Search : jumpjump

    • @blankblank9621
      @blankblank9621 3 года назад

      Fun And Surprising Game is here.

    • @blankblank9621
      @blankblank9621 3 года назад +1

      playtime is short but,

    • @blankblank9621
      @blankblank9621 3 года назад

      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 3 года назад

      Thank you

  • @RC32Smiths01
    @RC32Smiths01 3 года назад +80

    "Why be right when you can approximate?"

    • @livedandletdie
      @livedandletdie 3 года назад +10

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

  • @JTCano42
    @JTCano42 3 года назад +107

    The Forbidden Math

  • @rentristandelacruz
    @rentristandelacruz 3 года назад +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.

    • @omgmaster9985
      @omgmaster9985 3 года назад +14

      Gauss-Seidel, Picard aaaaah

    • @jpheitman1
      @jpheitman1 3 года назад +14

      Just finished it two weeks ago...
      AAAHHHHH

    • @Lynx-vi3bi
      @Lynx-vi3bi 3 года назад +14

      Bisection method :D

    • @alexandroskarypidis1891
      @alexandroskarypidis1891 3 года назад +9

      I learned FORTRAN in uni when doing this stuff! I'd forgotten I once knew FORTRAN!

    • @moriarteaa4692
      @moriarteaa4692 3 года назад

      Just had this Yesterday 😂

  • @kazuhoshiinoue2695
    @kazuhoshiinoue2695 3 года назад +393

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

    • @billferner6741
      @billferner6741 2 года назад +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 11 месяцев назад +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 Месяц назад

      Applied Mathematicians: We need to get exactly close enough!

  • @adityachk2002
    @adityachk2002 3 года назад +224

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

    • @Simpson17866
      @Simpson17866 2 месяца назад

      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 3 года назад +626

    Ah, the fundamental theorem of engineering.

    • @Ryanisthere
      @Ryanisthere 3 года назад +60

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

    • @vendettaanonimous5545
      @vendettaanonimous5545 3 года назад +2

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

    • @vendettaanonimous5545
      @vendettaanonimous5545 3 года назад +15

      and sin(x) = x 😂😂

    • @black_jack_meghav
      @black_jack_meghav 3 года назад +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 3 года назад +3

      @@black_jack_meghav r/woooosh

  • @Cralcker
    @Cralcker 3 года назад +118

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

  • @aenesturan
    @aenesturan 3 года назад +78

    first law of engineering: everything is linear

  • @davidbeckham2715
    @davidbeckham2715 3 года назад +79

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

  • @PapaFlammy69
    @PapaFlammy69 3 года назад +577

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

  • @rbpict5282
    @rbpict5282 3 года назад +50

    That's a really cool formula

  • @iangolsby8471
    @iangolsby8471 3 года назад +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 3 года назад +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 3 года назад +17

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

  • @benthayermath
    @benthayermath 3 года назад +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 2 года назад +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 3 года назад +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 3 года назад +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 2 года назад +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 3 года назад +14

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

  • @FranzBiscuit
    @FranzBiscuit 3 года назад +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 3 года назад +3

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

  • @machinedgod
    @machinedgod 3 года назад +4

    Quickly becoming my favorite youtube channel!

  • @EmperorSaistone
    @EmperorSaistone 3 года назад

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

  • @ssquarkgaming1405
    @ssquarkgaming1405 Год назад +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 3 года назад +12

    quality content
    as always

  • @AmitKumar-xw5gp
    @AmitKumar-xw5gp 3 года назад +2

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

  • @gastonhebert9967
    @gastonhebert9967 3 года назад

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

  • @C0MPLEXITY
    @C0MPLEXITY 3 года назад

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

  • @shrideepgaddad8721
    @shrideepgaddad8721 3 года назад +4

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

  • @MrMoore0312
    @MrMoore0312 3 года назад

    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 3 года назад

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

  • @davidhicks8290
    @davidhicks8290 3 года назад +2

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

  • @vincentdavis8960
    @vincentdavis8960 3 года назад +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 Год назад

    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 3 года назад +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 3 года назад +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 3 года назад +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 3 года назад +1

    Awesome video!

  • @daviddabeegukabassima8232
    @daviddabeegukabassima8232 10 месяцев назад

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

  • @tomcarroll6744
    @tomcarroll6744 10 месяцев назад

    Good stuff. Nice job.

  • @feuerrm
    @feuerrm 3 года назад +1

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

  • @justinmccoy4270
    @justinmccoy4270 3 года назад +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 Год назад

    Thank you very much for this video.

  • @TheDecooledaan
    @TheDecooledaan 3 года назад +1

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

  • @rajbunsha8834
    @rajbunsha8834 3 года назад

    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 3 года назад

    Beautiful!

  • @TylinaVespart
    @TylinaVespart 3 года назад

    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 3 года назад

    great vid as always

  • @udaysrivastava1957
    @udaysrivastava1957 3 года назад

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

  • @sunnohh
    @sunnohh 3 года назад

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

  • @dylgir1332
    @dylgir1332 3 года назад

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

  • @AdityaKumar-ij5ok
    @AdityaKumar-ij5ok 3 года назад +1

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

  • @tommyhuffman7499
    @tommyhuffman7499 3 года назад

    Very cool video!!

  • @LaserFur
    @LaserFur 3 года назад +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.

  • @matthewao
    @matthewao 3 года назад +3

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

  • @mahdialhassan6802
    @mahdialhassan6802 2 года назад

    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 3 года назад

    I read this under the heading computational methods
    TODAY!!

  • @jessstuart7495
    @jessstuart7495 3 года назад +1

    Chebyshev Approximations are also very useful.

  • @bittubabu4178
    @bittubabu4178 2 года назад

    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 3 года назад +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 3 года назад

    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 3 года назад

    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 3 года назад

    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 3 года назад +5

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

  • @soyokou.2810
    @soyokou.2810 3 года назад +1

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

  • @marsp2691
    @marsp2691 3 года назад +8

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

  • @dakkadakka4036
    @dakkadakka4036 3 года назад

    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 3 года назад

    pretty cool stuff

  • @ARKGAMING
    @ARKGAMING 3 года назад

    The clock looks awesome

  • @naswinger
    @naswinger 3 года назад

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

  • @juliusteo
    @juliusteo 3 года назад +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 3 года назад +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 3 года назад

    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 3 года назад

    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 3 года назад

    THANK YOU.

  • @WLand10
    @WLand10 2 года назад

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

  • @yugdesai4140
    @yugdesai4140 3 года назад

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

  • @onstantinosameranis4674
    @onstantinosameranis4674 3 года назад

    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 2 года назад

    ¡Gracias!

  • @danieljulian4676
    @danieljulian4676 3 года назад

    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 2 года назад

    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
    @danielsantrikaphundo4517 Год назад

    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 3 года назад

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

  • @cesaramaro6933
    @cesaramaro6933 3 года назад +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 Год назад

    amazing

  • @liamodonovan5374
    @liamodonovan5374 3 года назад

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

  • @tedchirvasiu
    @tedchirvasiu 3 года назад

    Awesome

  • @grimreaper173
    @grimreaper173 3 года назад

    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 Год назад

    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 3 года назад

    This video came out approximately on my birthday

  • @DeGuerre
    @DeGuerre 3 года назад

    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 3 года назад

    Legendary

  • @nix_
    @nix_ 3 года назад +35

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

  • @marklu5521
    @marklu5521 2 года назад +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 3 года назад +1

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

  • @aidanokeeffe7928
    @aidanokeeffe7928 3 года назад +7

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

  • @makkusaiko
    @makkusaiko 2 года назад

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