Why do trig functions appear in Euler's formula?

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  • Опубліковано 31 гру 2024

КОМЕНТАРІ • 184

  • @sinaahadi4787
    @sinaahadi4787 Рік тому +35

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

  • @gilbertmiya4199
    @gilbertmiya4199 7 місяців тому +6

    Superlative. Best teachers are on UA-cam!

  • @longsteinpufferbatch4949
    @longsteinpufferbatch4949 3 роки тому +15

    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!

  • @giannisr.7733
    @giannisr.7733 3 роки тому +64

    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

  •  3 роки тому +24

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

  • @JTtheking134
    @JTtheking134 2 роки тому +4

    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.

  • @indocesare14
    @indocesare14 3 роки тому +4

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

  • @chukwunta
    @chukwunta 8 місяців тому +3

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

  • @MikeStallings2023
    @MikeStallings2023 6 місяців тому +3

    First time for me that someone described it so simply and obviously.

  • @sardineman8994
    @sardineman8994 3 роки тому +12

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

  • @jasonmaguire9425
    @jasonmaguire9425 Рік тому +2

    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.

  • @sirousmohseni4
    @sirousmohseni4 4 дні тому

    You are doing a great job unpacking so much in this video.
    I need to watch it again to absorb more if it.

  • @Jaryism
    @Jaryism 11 місяців тому +1

    Best explanation of all vids on the internet and straight forward

  • @andresquiroga2400
    @andresquiroga2400 3 роки тому +1

    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 2 роки тому +1

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

  • @alexcartwright8197
    @alexcartwright8197 7 місяців тому +1

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

  • @RisetotheEquation
    @RisetotheEquation 3 роки тому +7

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

  • @godfreytomlinson2282
    @godfreytomlinson2282 7 місяців тому +1

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

  • @neutralzone7775
    @neutralzone7775 Місяць тому

    Amazing video, Physics major and we use this all the time, now I have a much more intuitive understanding of the Euler's formula

  • @Ganerrr
    @Ganerrr 3 роки тому +8

    here before this channel blows up

  • @siener
    @siener 3 роки тому +1

    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.

  • @MrPabloguida
    @MrPabloguida Рік тому +4

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

  • @Sarah-mp9lb
    @Sarah-mp9lb 7 місяців тому +1

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

  • @fariesz6786
    @fariesz6786 3 роки тому +2

    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.

  • @indrokrisna108
    @indrokrisna108 Рік тому +1

    Outstanding!!!!!! clearly comprehensive

  • @babujimitra7920
    @babujimitra7920 Рік тому +1

    Magnificent.... expect something more like this

  • @drbibhisanroy2219
    @drbibhisanroy2219 Рік тому +1

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

  • @GiulioJiang
    @GiulioJiang 2 роки тому +1

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

  • @alic4631
    @alic4631 Рік тому +1

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

  • @thenixaless7493
    @thenixaless7493 2 роки тому

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

  • @safwathullahsaud4104
    @safwathullahsaud4104 5 місяців тому

    Beautifully explained, connecting all the dots reaching the eureka moment. Thank you so much. Have subscribed to your channel immediately 😁

  • @samisiddiqi5411
    @samisiddiqi5411 3 роки тому +2

    Best video on this topic I've seen.

  • @Soumyadip.B07
    @Soumyadip.B07 2 місяці тому

    You deserve more subscribers, amazing explanation loved it.

  • @loszhor
    @loszhor Рік тому +1

    Thank you for the information.

  • @longsteinpufferbatch4949
    @longsteinpufferbatch4949 3 роки тому +2

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

  • @adleneboulebtateche156
    @adleneboulebtateche156 3 роки тому +3

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

  • @thelifeofibo
    @thelifeofibo Місяць тому

    i spent a day trying to prove this with the taylor series, still my most enjoyable day in terms of math

  • @WalterHarding-m7l
    @WalterHarding-m7l Рік тому +2

    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!

  • @sisyphus645
    @sisyphus645 3 роки тому +1

    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

  • @TheJara123
    @TheJara123 3 роки тому +2

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

  • @aaqilkhan
    @aaqilkhan 3 роки тому +2

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

  • @davidm9442
    @davidm9442 3 роки тому +2

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

  • @zakirreshi6737
    @zakirreshi6737 3 роки тому

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

  • @DanielL143
    @DanielL143 Рік тому

    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!

  • @gamalateya2413
    @gamalateya2413 3 роки тому +1

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

  • @norbi8072
    @norbi8072 Місяць тому

    That was magical...simple and elegant!

  • @johnzinhoinhoinho
    @johnzinhoinhoinho 3 роки тому +2

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

  • @T0NYD1CK
    @T0NYD1CK Рік тому +1

    I would argue that the start of the video is back to front in that sines have less to do with triangles and more to do with circles. Strangely, we never seem to be taught it that way round. Sines are "circular functions" and the word itself comes from sinus meaning curve.
    So, I think we should really start from the unit circle with the "curve height" above the x-axis being called "sine" and it is the sine of the arc length, or angle if you prefer. The related coordinate of that y-axis sine value is the co-sine. That is, it accompanies the sine. From that the trig stuff follows.
    If you add a tangent to the point then see where that line cuts the y-axis and x-axis we see where the secant (based on secare: to cut) comes from. All the well-known trig relationships then follow using similar triangles.

  • @dontawanpitak
    @dontawanpitak 3 роки тому +1

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

  • @PETERTRITSCH
    @PETERTRITSCH Рік тому

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

  • @MarcoMate87
    @MarcoMate87 3 роки тому +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.

  • @SeeTv.
    @SeeTv. 3 роки тому +64

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

    • @jHan
      @jHan  3 роки тому +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 2 роки тому

      @@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.

  • @hichamhenna8011
    @hichamhenna8011 Рік тому

    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!

  • @adlg5158
    @adlg5158 3 роки тому +3

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

  • @ravisinha312
    @ravisinha312 3 роки тому +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!

  • @RuanD
    @RuanD 3 роки тому +1

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

  • @ClearerThanMud
    @ClearerThanMud 3 роки тому +2

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

  • @Posesso
    @Posesso 3 роки тому +2

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

  • @skillick
    @skillick Рік тому +1

    Great video, best I've seen on this topic

  • @VatLyChill
    @VatLyChill 9 місяців тому +1

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

  • @janosruf2183
    @janosruf2183 3 роки тому +1

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

  • @nidalapisme
    @nidalapisme 3 роки тому +7

    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

  • @chabanehacene
    @chabanehacene 3 роки тому +2

    Amazing. More video like that please

  • @Spongman
    @Spongman 3 роки тому +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.

  • @kanhaiyalalrajput3215
    @kanhaiyalalrajput3215 10 місяців тому

    Great Job 👍👌. I needed this explanation.

  • @jacobmacdonald223
    @jacobmacdonald223 3 роки тому

    Best explanation I've heard yet

    • @Caturiya
      @Caturiya 3 роки тому

      Just a shortcut ua-cam.com/video/56BpfqpR7Ko/v-deo.html

  • @claudelorrain-bouchard6941
    @claudelorrain-bouchard6941 Рік тому +3

    Wish "imaginary numbers" were just called "lateral numbers"

    • @JasonCunliffe
      @JasonCunliffe 3 місяці тому

      Geometric numbers
      Circular numbers
      Spatial numbers
      Whole numbers
      Orbital numbers
      Spherical numbers
      Angular Numbers
      Rotational numbers
      ???

  • @Founder2721
    @Founder2721 2 місяці тому

    I started gasping and lighting screaming when i saw the end of the taylor series proof. Im bewildered

    • @pelasgeuspelasgeus4634
      @pelasgeuspelasgeus4634 2 місяці тому

      That proof is wrong. Taylor series are valid for real integers, not marvel universe numbers like i*x.

    • @Founder2721
      @Founder2721 Місяць тому

      @pelasgeuspelasgeus4634 *bigger gasp*

    • @pelasgeuspelasgeus4634
      @pelasgeuspelasgeus4634 Місяць тому

      @@Founder2721 meaning?

  • @TruthOfZ0
    @TruthOfZ0 9 місяців тому

    I love this formula..its so beautiful !!

  • @darkarz5331
    @darkarz5331 3 роки тому +2

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

  • @culater
    @culater Рік тому +1

    Thanks for your great work 👍

  • @H3XED_OwO
    @H3XED_OwO Рік тому

    11:53 -12:07 it's all coming together! 🤯

  • @therealowenmcbride
    @therealowenmcbride 10 місяців тому

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

  • @navigatorspark5215
    @navigatorspark5215 4 місяці тому

    beautifully explained

  • @kiepier
    @kiepier 2 роки тому

    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.

  • @mlodyG_750
    @mlodyG_750 8 місяців тому

    great explanation!

  • @demr04
    @demr04 Рік тому

    A think the first explanation needs at least to understand curves in space and their derivatives (vector fields), but the second only needs basic differential calculus, so the second is a better approach i think for explain it.
    I like the fact, using linear algebra, that the exponential function is the eigenvector of the differential operator for or eigenvalue, and then a second-degree differential operator has as eigenvector the trig. functions with eigenvalue = -1, so the trig. function must be a linear combination of exps; then the fact that the linear operator is degree two, so the eigenvalue of that operator corresponde to the square of the eigenvalue of the first-degree operator, tales that the eigenvalue of the linear eq. D^2(y) = -y it's just "i", and then your initial conditions dictate the linear combination of exponential functions. That result requieres to know linear algebra and calculus, but for me it's the less "magical" because you are not matching what it seems pears and apples, or just pluging "i" in exp because someone was curious.

  • @miro.s
    @miro.s 3 роки тому +3

    Very clear speaking and graphics. Only derivatives of e^(ix) are discrete so at that point your proof is wrong. You should show that derivatives can be uniquely extended to fractional derivatives. Then that the extension is smooth. Then that fractional derivatives of e^(ix) don't change absolute value of the function. Then you finish the proof showing that e^(ix) = cos x +i sin x

    • @angelmendez-rivera351
      @angelmendez-rivera351 Рік тому

      The statement that derivatives can be uniquely extended to fractional derivatives is incorrect. In fact, it can be rigorously proven that over any vector space, a linear operator which is surjective and has nontrivial kernel cannot be fractionalized, even if you disregard the ambiguities that inherently emerge with fractional exponentiation in the scalar field.

  • @CuriousCyclist
    @CuriousCyclist 3 роки тому

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

  • @thomasolson7447
    @thomasolson7447 Рік тому

    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).

  • @codatheseus5060
    @codatheseus5060 9 місяців тому

    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

  • @darthvitiate7373
    @darthvitiate7373 3 роки тому

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

  • @2001ayham
    @2001ayham 3 роки тому

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

    • @carultch
      @carultch Рік тому

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

  • @soumenpradhan1855
    @soumenpradhan1855 3 роки тому +1

    Absolutely amazing 🤗

  • @dr.rahulgupta7573
    @dr.rahulgupta7573 3 роки тому

    Excellent presentation. vow !!

  • @tomerhendel3975
    @tomerhendel3975 Рік тому +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 Рік тому +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.

  • @djredrover
    @djredrover 2 роки тому

    really well done!!!!

  • @annashshaha6917
    @annashshaha6917 3 роки тому +1

    Thnks for uploading such a great video ❤💞😊

  • @Bleb1k_irl
    @Bleb1k_irl 3 роки тому +1

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

  • @ketaksingh5465
    @ketaksingh5465 2 місяці тому

    amazing man! subscribed

  • @hqs9585
    @hqs9585 11 місяців тому

    Great video!

  • @fifaham
    @fifaham Рік тому

    Truly amazing discovery - what is even more amazing is the human brain who invented the magical J = SQRT(-1) and found its correlation to trigonometry. It is all hidden inside our brains, and manufactured by the Universe !

  • @621Tomcat
    @621Tomcat 3 роки тому

    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

  • @rajanvk939
    @rajanvk939 3 роки тому

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

  • @pokemonxyzseriesunofficial206
    @pokemonxyzseriesunofficial206 3 роки тому

    U know what. You should make more of it.

  • @jeremychen425
    @jeremychen425 3 роки тому

    Very good video, thank you!

  • @lajont
    @lajont 3 роки тому

    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  3 роки тому

      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 Рік тому

      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.

  • @gerardjacquemier5137
    @gerardjacquemier5137 3 роки тому

    Explication merveilleusement claire

  • @Dr.1.
    @Dr.1. 3 роки тому +1

    absolutely amazing I do have one tiny thing
    at 12:27 and 12:30 the animation is kind of messy and I had to replay that part to see what happened
    no complains tho... also cool video

  • @BRYDN_NATHAN
    @BRYDN_NATHAN 3 роки тому +1

    Thank you. The dangle has an angle. 👍