Why do trig functions appear in Euler's formula?

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  • čas přidán 7. 06. 2024
  • Why do trig functions appear in Euler’s formula? This was the question I had when I first saw Euler’s formula. This connection between trigonometry and exponents seems so unexpected, especially along with complex numbers. To answer this question, we must journey into the intricate and beautiful mathematical relationship between trig functions, e, and complex numbers. We will look at two different ways to approach this question: one using dynamics, geometry, and the complex plane, and the other using Taylor and Maclaurin series. Both are equally fascinating, and both reach the same, amazing result by using a lot of beautiful math.
    0:00 - Intro
    0:38 - Unit circle on complex plane approach
    7:30 - Taylor and Maclaurin series approach
    12:39 - Conclusion
    Additional Resources:
    Geometric proof of the derivatives of sin(x) and cos(x)
    ocw.mit.edu/courses/mathemati...
    Animations were made by Manim, an open-source python-based animation program by 3Blue1Brown.
    github.com/3b1b/manim
    This video was submitted to 3Blue1Brown's SoME (Summer of Math Exposition).
    3b1b.co/some1

Komentáře • 157

  • @sinaahadi4787
    @sinaahadi4787 Před 8 měsíci +15

    Math and Physics are art and they are needed to perform by an artist. That was really beautiful.

  •  Před 2 lety +21

    Very well done; content- and animation-wise. My favourite video in the SoME-contest so far.

  • @giannisr.7733
    @giannisr.7733 Před 2 lety +54

    In our math class in uni, the teacher said we had a function A that has all the properties of the sin function, but he didn't tell us. We were talking about the sin function in it's polynomial form, and we only realised it after 3 hours of it being taught

  • @sardineman8994
    @sardineman8994 Před 2 lety +11

    You put all of my thoughts about euler's Formula into a beautiful video great job

  • @adleneboulebtateche156
    @adleneboulebtateche156 Před 2 lety +2

    Absolutely stellar. I can't thank you enough for this video. Looking forward to watching new stuff.

  • @longsteinpufferbatch4949
    @longsteinpufferbatch4949 Před 2 lety +11

    And you not only enlightened me why e^(ix)=cosx + isinx but also why d/dx of cosx and d/dx of sinx are -sinx and cosx INTUITIVELY, so far i only had them memorized. I never knew this great visualisation before! This is gold for a high schooler like me.
    Please keep doing your amazing work! I like when math is this intuitive. Subbed!

  • @davidm9442
    @davidm9442 Před 2 lety +1

    Awesome video! I've always been intrigued by the conection between trig functions and complex numbers. I really enjoyed your explanations.

  • @JTtheking134
    @JTtheking134 Před rokem +2

    Damn, how did you enlighten me with all this in only 13 minutes!
    Very underrated channel, youre so good at explaining, and you even give examples.

  • @jasonmaguire9425
    @jasonmaguire9425 Před 9 měsíci

    You've made it possible for me and I'm sure many many others to now visualise these relationships and connect the dots. Thank you so much.

  • @RisetotheEquation
    @RisetotheEquation Před 2 lety +6

    Great job! You made everything super clear and added some insight along the way - the best combination :) BTW - clever channel name!

  • @aaqilkhan
    @aaqilkhan Před 2 lety +1

    Amazingly done. Explanation and visualization were very well presented. Great job!

  • @MrPabloguida
    @MrPabloguida Před rokem +4

    This is some high quality material right here. I'm looking forward for your video on Fourier transform.

  • @ravisinha312
    @ravisinha312 Před 2 lety +3

    Looking forward to more videos! Thanks for such a lucid explanation and clear animations. Would be great if you could also share your backstory as in what goes behind the scenes to plan and create such a video. That's will make more people curious to explore manim and other tools to create more such open source videos in their domain of interest. Thanks again!

  • @andresquiroga2400
    @andresquiroga2400 Před 2 lety

    nothing new to me but still, but it completely deserves a thumbs up, these kinds of animations and explanations are always appreciated, hope you continue with these kinds of videos

  • @simonwax7575
    @simonwax7575 Před 2 lety

    Great explanation. This I think is the essential insight of the 2 years of study I’ve just completed reduced to 15mins. Thank you.

  • @indocesare14
    @indocesare14 Před 2 lety +2

    These educational videos made with Manim are spawning everywhere lately. And I couldn't be more grateful!

  • @Jaryism
    @Jaryism Před 4 měsíci

    Best explanation of all vids on the internet and straight forward

  • @chukwunta
    @chukwunta Před měsícem

    Videos like these are now my best way to learn mathematics. Thanks so much. More elbow-grease to your efforts. 👏

  • @ClearerThanMud
    @ClearerThanMud Před 2 lety +1

    Great job -- subscribed, and looking forward to more!

  • @johnzinhoinhoinho
    @johnzinhoinhoinho Před 2 lety +1

    Great explanation, very clear train of thought. I wish all my teachers would be like you

  • @godfreytomlinson2282
    @godfreytomlinson2282 Před 10 dny

    This video was concise and to the point. Clear information bundled up tight.

  • @audioplayerplaysaudio3276
    @audioplayerplaysaudio3276 Před 3 měsíci

    Super cool! This video of yours totally made my day/night! It's just such a good compression/combination of trig functions, complex numbers, Euler's number, and Taylor series. Of course, I have seen such contents linked in videos of 3Blue1Brown, Mathologer and others, but yours just happened to be the one tipping me over into finally GETTING IT🥳So thanks jHan!

  • @alexcartwright8197
    @alexcartwright8197 Před 12 dny

    Superb video, a work of art. Super easy to follow - you guide us well through these topics. Thank you.

  • @RuanD
    @RuanD Před 2 lety

    Very good! You really answered my question about that relationship and the usefulness of complex functions.

  • @knightace742
    @knightace742 Před 2 lety

    This is easier than I thought it was. Thank you for explaining.

  • @alic4631
    @alic4631 Před 7 měsíci

    Beautiful man, just beautiful, I like how you started with basics

  • @fariesz6786
    @fariesz6786 Před 2 lety +1

    thank you!
    this is the first time i see a good intuitive motivation for Euler's formula _beside_ using the Taylor expansion and that always bugged me.

  • @longsteinpufferbatch4949
    @longsteinpufferbatch4949 Před 2 lety +1

    I had the same question when i saw it recently for the first time at school. Thanks for the video :)

  • @TheJara123
    @TheJara123 Před 2 lety +1

    Thoughtful, beautiful and insightful...keep going because this is road not taken in the math world...and of course thanks...

  • @samisiddiqi5411
    @samisiddiqi5411 Před 2 lety +1

    Best video on this topic I've seen.

  • @siener
    @siener Před 2 lety

    Great video! One of the things I don't think gets enough attention when discussing Euler's formula is this deep connection between trigonometric functions and exponential functions. It blew my mind when I realized that exponential functions are periodic on the imaginary axis and while sin and cos grow to infinity.

  • @gamalateya2413
    @gamalateya2413 Před 2 lety

    Amazing
    For years 😁 revolving around youtube to find simple explanation
    Finally you are 🌺🌺

  • @gilbertmiya4199
    @gilbertmiya4199 Před 27 dny

    Superlative. Best teachers are on CZcams!

  • @indrokrisna108
    @indrokrisna108 Před rokem

    Outstanding!!!!!! clearly comprehensive

  • @janosruf2183
    @janosruf2183 Před 2 lety

    Amazing animation and explanation! You have a new subscriber :)

  • @SayedHamidFatimi
    @SayedHamidFatimi Před 2 lety +1

    Love it! More content please!

  • @Sarah-mp9lb
    @Sarah-mp9lb Před 28 dny

    Wow! Thank you so much for this extremely helpful video!!

  • @Posesso
    @Posesso Před 2 lety +1

    I liked it a LOT!
    Very nice channel name :)

  • @SeeTv.
    @SeeTv. Před 2 lety +63

    Absolutely amazing for your first video!
    Question: How long did it take for you to learn Manim?

    • @jHan
      @jHan  Před 2 lety +27

      It took me maybe a month to get the basics down, but it may take more or less depending on what you want to animate.

    • @mihailmilev9909
      @mihailmilev9909 Před rokem

      @@jHan this is your first video!? Beautiful. I'm starting to see this more and more with people who upload these pieces of amazing content for the first time as 3B1B challenge submissions.

  • @babujimitra7920
    @babujimitra7920 Před 11 měsíci

    Magnificent.... expect something more like this

  • @thenixaless7493
    @thenixaless7493 Před rokem

    The simple way you explain this, combined with the beautiful narration is just...
    Even 10th grade me could understand this!!

  • @chabanehacene
    @chabanehacene Před 2 lety +1

    Amazing. More video like that please

  • @GiulioJiang
    @GiulioJiang Před rokem

    incredibly good explanation. Every high school and university should show this video

  • @skillick
    @skillick Před rokem

    Great video, best I've seen on this topic

  • @drbibhisanroy2219
    @drbibhisanroy2219 Před 7 měsíci

    please make more content. Very high-quality sciences. Thanks a lot

  • @nidalapisme
    @nidalapisme Před 2 lety +6

    B E A utiful! This reminds me of an 8-part video from Mr. Woo's channel explaining the same thing but he ends it to Euler's identity. Perhaps the next video from you would be explaining the most beautiful equation in the world in such a compact way.
    +1 from me :D

  • @sisyphus645
    @sisyphus645 Před 2 lety

    With quality as high as this I thought you'd have over a million subscribers! Really, well done bro! Remember me when you make it big haha XD

  • @dontawanpitak
    @dontawanpitak Před 2 lety

    Holy smokes!!! This is amazing!!! I don't really follow the first one but for the Taylor series one, that's unreal!!!

  • @user-wt4lb9hg3r
    @user-wt4lb9hg3r Před 8 měsíci +1

    Excellent presentation. Now, discuss the derivation of Schoedinger’s equation. Your detail could clarify that. Also, you should do a segment on the natural log and complex numbers. Thanks!

  • @culater
    @culater Před 7 měsíci +1

    Thanks for your great work 👍

  • @loszhor
    @loszhor Před 10 měsíci +1

    Thank you for the information.

  • @mlodyG_750
    @mlodyG_750 Před měsícem

    great explanation!

  • @dr.rahulgupta7573
    @dr.rahulgupta7573 Před 2 lety

    Excellent presentation. vow !!

  • @soumenpradhan1855
    @soumenpradhan1855 Před 2 lety +1

    Absolutely amazing 🤗

  • @djredrover
    @djredrover Před rokem

    really well done!!!!

  • @annashshaha6917
    @annashshaha6917 Před 2 lety +1

    Thnks for uploading such a great video ❤💞😊

  • @jacobmacdonald223
    @jacobmacdonald223 Před 2 lety

    Best explanation I've heard yet

    • @Caturiya
      @Caturiya Před 2 lety

      Just a shortcut czcams.com/video/56BpfqpR7Ko/video.html

  • @jeremychen425
    @jeremychen425 Před 2 lety

    Very good video, thank you!

  •  Před 2 měsíci

    Hello, is there any email/discord to reach out to you?

  • @zakirreshi6737
    @zakirreshi6737 Před 2 lety

    Well done👌👌👏.....12:08 side point yo be noted!!

  • @TruthOfZ0
    @TruthOfZ0 Před 2 měsíci

    I love this formula..its so beautiful !!

  • @hqs9585
    @hqs9585 Před 5 měsíci

    Great video!

  • @CuriousCyclist
    @CuriousCyclist Před 2 lety

    Good quality content man! A bit fast but people can pause if they need a moment to think.

  • @PETERTRITSCH
    @PETERTRITSCH Před 9 měsíci

    It's the first time I can figure out what the Euler equation means! And that means a lot for me!!!

  • @DanielL143
    @DanielL143 Před 9 měsíci

    Excellent approach; keeping it a higher and conceptual level is the key to understanding the connections between the various mathematical concepts. Getting too lost in the details or just learning only how to calculate in a rote fashion kills understanding in favor of rigor. Both are needed.
    The traditional education system teaches the number crunching and kills interest in a truly beautiful language (math) by forgetting to connect all of the concepts (1) functions (2)the properties of the all important exponential function (3) derivatives (4) the application to unit vectors and the imaginary dimension that enables rotation (5) the trigonometric connection and (6) the polynomial expression of the same function using a convergent but infinite series (constraining infinity and making it work for us is truly one of the master strokes of mathematics).
    Then comes applications; electrical engineering and quantum mechanics which are all about waves with an imaginary component and how they sum.
    True understanding happens by integrating all three levels (1) the mechanics of number crunching which allows us to speak the language (2) the high level conceptual connections between various mathematical topics and approaches which validates the consistency of the language and (3) the application of mathematics as a tool for modeling systems, solving problems, optimizing and evolving systems and
    Finally there is the mystery that surrounds the fit between the model and the system and the misfit between GR and QM and something deeply hidden. Beauty and mystery, it doesn't get any better. Thanks!

  • @MarcoMate87
    @MarcoMate87 Před 2 lety +1

    Very well done video, and excellent explanation. There's another proof for the coincidence of f(x) = e^(ix) and g(x) = cos(x) + i sin(x) for every real x. These two functions both solve the Cauchy problem y' = iy with y(0) = 1. As the solution of this problem is unique, f and g must be equal everywhere.

  • @darkarz5331
    @darkarz5331 Před 2 lety +2

    Dont know nothing about maths but i had this in recomended, guess your getting blessed by the algorithm. Looks interesting tho

  • @mighty8357
    @mighty8357 Před 2 lety

    Splendid!!

  • @GanerRL
    @GanerRL Před 2 lety +7

    here before this channel blows up

  • @kanhaiyalalrajput3215
    @kanhaiyalalrajput3215 Před 3 měsíci

    Great Job 👍👌. I needed this explanation.

  • @Spongman
    @Spongman Před 2 lety +1

    very good. although, some of the manim latex transitions could be redone to minimize the amount of text that changes. eg @12:24 only the 'cos x' part needs to change, but the whole equation goes through the mangling transition which hides the fact that it's only the real part on the rhs that's changing.

  • @2001ayham
    @2001ayham Před 2 lety

    Hey great video! I'm studying Electrical engineering and this was very interesting for my signals course.

    • @carultch
      @carultch Před rokem

      I like how Heaviside's Pi and Lambda function are named by symbols that look like the shape of the signal.

  • @gerardjacquemier5137
    @gerardjacquemier5137 Před 2 lety

    Explication merveilleusement claire

  • @PlanetNumeracy
    @PlanetNumeracy Před 3 měsíci

    Amazing!

  • @rajanvk939
    @rajanvk939 Před 2 lety

    Wow excellent explanation. Could you please 🙏 make videos on Vector Geometry

  • @BRYDN_NATHAN
    @BRYDN_NATHAN Před 2 lety

    Thank you. Favorite number 👍

  • @Ni999
    @Ni999 Před 2 lety

    _Excellent._

  • @darthvitiate7373
    @darthvitiate7373 Před 2 lety

    ngl thought this a was a 3blue 1 brown video then i saw the channel name keep up the good work

  • @pokemonxyzseriesunofficial206

    U know what. You should make more of it.

  • @SD-mc9xm
    @SD-mc9xm Před 2 lety

    ❤️ you explain it so beautifully, lol you remind me of 3b1b

  • @adlg5158
    @adlg5158 Před 2 lety +2

    This video made Euler's identity the clearest to me, how do you not have more than 50 subscribers?

  • @leeris19
    @leeris19 Před 29 dny

    HELLA BEAUTIFUL!

  • @ILSCDF
    @ILSCDF Před 2 lety

    Beautiful

  • @dankdungeon5104
    @dankdungeon5104 Před 2 lety

    Insane video

  • @BRYDN_NATHAN
    @BRYDN_NATHAN Před 2 lety +1

    Thank you. The dangle has an angle. 👍

  • @VictorMasnikov
    @VictorMasnikov Před 2 lety +1

    Hey, love this lesson!
    Now i can create more complex fractals than ever, thanks!!!

  • @CoupleMadness
    @CoupleMadness Před 2 lety

    You are amazing sir 🥰 , I love Mathematics ❤️ so please do a favour for me keep making such amazing videos ❣️ Love from India 😍

  • @therealowenmcbride
    @therealowenmcbride Před 3 měsíci

    Trigonometry, calculus, complex numbers, EVERYTHING is in this video😭

  • @manfredbogner9799
    @manfredbogner9799 Před 5 měsíci

    very good

  • @kiepier
    @kiepier Před rokem

    At 9:33 does cosθ = dy/dθ because the triangle with θ at the origin is similar to the triangle with θ on the unit circle? I guess it makes sense if the magnitude of the rate of change is constant like e^ix.

  • @codatheseus5060
    @codatheseus5060 Před 2 měsíci

    I love using (x+y) instead of just x in my Taylor series. You gotta double the number next to the factorial to keep it good

  • @4NAML
    @4NAML Před 2 lety

    Wow
    I've been used this about 2 years ago but I never knew why that happen

  • @tomerhendel3975
    @tomerhendel3975 Před rokem +1

    Great video! I just finished watching the first part, of the geometrical approach, and got most of the proof intuitively, but there is one thing that still doesn't work out in my mind. Can someone please elaborate on why it is the case that the 90-degree angel of the derivative creates a circular pattern in the complex plane?

    • @dlinnoedlinnoe
      @dlinnoedlinnoe Před 11 měsíci +1

      Yeah, that moment at 6:00 and further is somewhat without any proofs. Blah-blah and voila - exp(ix) just is a circle. Not clear why at all. Not clear why derivative is there etc. Need to watch other channels.

  • @curtpiazza1688
    @curtpiazza1688 Před 4 měsíci

    Great STUFF! 😂

  • @621Tomcat
    @621Tomcat Před 2 lety

    I looked at the thumbnail and thought it was a 3b1b video
    Edit: read the description, now I know why
    Also edit: this video was very beautifully made

  • @hichamhenna8011
    @hichamhenna8011 Před 7 měsíci

    At time 06:25, he tells us that: (the derivative ie^(ix) has no real constant changing the function ==> this means that the magnitude of the derivative stays constant at 1); this statement that I wrote between brackets it is not as intuitive as I wish. Further explanation please!

  • @thomasolson7447
    @thomasolson7447 Před rokem

    I've been playing with the Lorentz Factor. e^(i*arctan(i*v/c))=(-v/c+1)/sqrt(-v^2/c^2+1) which is γ*(1-v/c).

  • @lajont
    @lajont Před 2 lety

    A nice and well thought out video, with nice explanations for why e^(ix)=cos(x)+i*sin(x).
    There is one thing that bugs me though, which would be that you without explanation use the power rule in order to find the derivative of e^(ix). This is nice, and totally ok to do, but it is not obvious that the derivative of complex numbers is well defined, exist, and have the chain rule. That is since the complex numbers can represent 2d-space, while the "normal" derivative is usually defined from a small change in 1d-space. I would not expect a full explanation of this here, but a comment would have been nice.
    Still, if you expect e^(ix) to show circular motion in advance, one could say that the motion would still be one dimensional, and therefore be able to give meaning to the derivative, but that would not be as rigourus as I think you wanted this video to be.
    I'm just rambling on at this point, but this is really just a minor thing to bring up, and I think that the rest of the video explained everything in a consistant and nice manner.

    • @jHan
      @jHan  Před 2 lety

      Yeah, I should've been a bit more rigorous. Complex differentiation does follow the chain, product, and quotient rules, and e^z is complex-differentiable in the entire complex plane, so we can simply use the chain rule. Perhaps proofs and deeper dive of these concepts could be a video for the future!

    • @angelmendez-rivera351
      @angelmendez-rivera351 Před rokem

      You are misunderstanding the concept. At no point are you actually required to take the derivative over a complex domain. Only the codomain is complex, the domain is still the set of real numbers.

  • @DheerajKumar-zb2ix
    @DheerajKumar-zb2ix Před 2 lety +1

    I hated maths before but now I want more videos from you ☺️☺️

  • @othmandont9355
    @othmandont9355 Před měsícem

    This is magic