Complex integration, Cauchy and residue theorems | Essence of Complex Analysis #6

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  • Опубликовано: 30 сен 2024

Комментарии • 659

  • @mathemaniac
    @mathemaniac  2 года назад +43

    Unlock new career opportunities and become data fluent today! Use my link bit.ly/MathemaniacDCJan22 and check out the first chapter of any DataCamp course for FREE!
    Support the channel on Patreon: www.patreon.com/mathemaniac
    Merch: mathemaniac.myspreadshop.co.uk/
    [hopefully, this time, the pinned comment won't disappear like last video, cos for some reason RUclips decides that a similar comment is spam lol]
    Please refer to the previous video for why I skipped the differentiation part: ruclips.net/video/F-kYuvSyC-A/видео.html
    This is the end of this video series, although I wouldn't say that complex analysis will disappear on this channel forever, just that it will only have occasional appearance if I feel like it.
    I know it's a bit "irresponsible" to leave out the details in the last bit of the video, but the main point in that part is that residue theorem is useful in real integrals, and to be honest, videos on this channel are sort of "inspirational" rather than "educational", in the sense that it is not intended to be rigorous, as said in about 15:26. If those details are really in demand, I could make a video about it, but it will most likely on the 2nd channel: ruclips.net/channel/UCWdGv5veEBYCn99pT7XJsjwvideos

    • @jacobhoward7579
      @jacobhoward7579 2 года назад +3

      Oh my God dude...
      I have been literally waiting for YEARS for a RUclipsr to make a professional visualization of this!! ...
      Words can't express my thanks...
      🙏

    • @dnickaroo3574
      @dnickaroo3574 Год назад +1

      I have fond memories of Complex Analysis from the 1970’s, but have only returned to Maths since retiring. I have studied Feynman on Theory of Fields recently, so I love the connection. Thanks for providing this outline.

  • @DrTrefor
    @DrTrefor 2 года назад +385

    Very impressed with this complex analysis series, well done!

    • @mathemaniac
      @mathemaniac  2 года назад +25

      Thank you so much :)

    • @duckymomo7935
      @duckymomo7935 2 года назад +13

      I agree, it was so clear, beautiful and insightful
      3B1B quality

    • @naman4067
      @naman4067 2 года назад +3

      Hi trefor

    • @scraps7624
      @scraps7624 2 года назад +3

      Your videos are incredible as well!

  • @nosnibor800
    @nosnibor800 2 года назад +637

    I watched this out of nostalgia. I am a retired Electrical Engineer and back in 1975 I covered this work on my final year maths syllabus of the HND, at Manchester Polytechnic, UK. I still don't fully understand it ; maths is so beautiful. I think this is applied in advanced control systems.

    • @RAyLV17
      @RAyLV17 2 года назад +31

      Yes it is applied in control systems. We n need complex visualization to determine the stability of a system. Something like poles and holes. I don't remember either haha, I learned it in my bachelor's in mechanical engineering.

    • @nosnibor800
      @nosnibor800 2 года назад +33

      @@RAyLV17 Ah the crossover between mechanical and electrical :-)

    • @naman4067
      @naman4067 2 года назад +7

      @@nosnibor800 now we have internet we can make our knowledge more deeper. Easy life 😌

    • @rahulpsharma
      @rahulpsharma 2 года назад +7

      I think used in Nyquist Criterion

    • @douglasortner6255
      @douglasortner6255 2 года назад +3

      Im a freshman in college for Electrical Engineering, looking forward to the challenge of figuring this stuff out.

  • @samyaksheersh712
    @samyaksheersh712 2 года назад +148

    Why on earth wouldn't anyone watch this till the end? It's such a beautiful result so elegantly presented! Keep up the good work!

    • @mathemaniac
      @mathemaniac  2 года назад +22

      Thanks for the compliment!
      Although I think that's all well-meaning, I do think that asking 40 minute of someone's time is difficult, however good the content is.

    • @samyaksheersh712
      @samyaksheersh712 2 года назад +3

      @@mathemaniac Yeah, Being a high school student, I didn't consider that. But it was a nice video anyway, and the results were really beautiful

    • @moreasmorebaes9996
      @moreasmorebaes9996 2 года назад +2

      @@samyaksheersh712 a fellow highschool student hear, how did you clear the prerequisites for complex analysis? I have to prepare a presentation and I really wanna make it about the value of residue calculus to solve real integrals and I barely know single vari calc.

    • @neplatnyudaj110
      @neplatnyudaj110 Год назад

      Flashbacks dude, flashbacks. But on the other hand, there were worse things in control theory classes.

  • @yinq5384
    @yinq5384 2 года назад +53

    Great as always!
    I never saw the "Work + i Flux" interpretation before. It's really helpful, just like the area/mass interpretation in real integral.

    • @mathemaniac
      @mathemaniac  2 года назад +3

      Glad you enjoyed it!

    • @nutelina
      @nutelina 2 года назад +1

      @@mathemaniac Please continue this trend, it was a great help indeed. Math can be confusing because of all the details, I love how you keep it simple with great analogies and don't slip into side-quests like 1blue1brown.

    • @BambinaSaldana
      @BambinaSaldana Год назад +1

      Hey guys I have a question. So area, velocity, acceleration, etc., all have representations in calculus, right? Area/distance is represented by the integral, velocity is represented by the derivative, and acceleration and its derivatives are represented by higher order derivatives. So, what is the physical interpretation of the antiderivative? Say we have a function f(x). This represents our distance. What would its antiderivative be? Is the antiderivative just pure math that's only really useful for velocity and higher order derivatives, or does it have actual use in physics?

    • @TheTKPizza
      @TheTKPizza Год назад

      @@BambinaSaldana Maybe a bit late, but since you were talking about time derivatives of spacial coordinates (velocity, acceleration, etc.), the time based "antiderivative" would be called "Absement". It is basically an overall measure of the distance and time, an object has been displaced from its initial position. Feel free to read the wikipedia article abuot it for more details. I think, it is a very smart question, I was wondering the same a few years ago and looked it up. :)

    • @BambinaSaldana
      @BambinaSaldana Год назад

      @TheTKPizza Ohh so the antiderivative is basically how much distance was covered? Or how much distance the object has had from its origin?

  • @nezavipavc172
    @nezavipavc172 2 года назад +71

    Physics student here, and I have to say that this has made my understanding of complex analysis *so* much better! You explained everything way more intuitively than how our professor presented the material, so thank you for making this video!

  • @MaxxTosh
    @MaxxTosh 2 года назад +44

    By far my favorite video covering complex analysis, ever. You put together nearly all the integration topics so well!

  • @evaxu1325
    @evaxu1325 Год назад +64

    40:08 Watched to the end! An Oxford math student here :)) I am so grateful that you made this series of video. I was previewing complex analysis during the summer and suffering until I discovered your essence of complex analysis. It made the subject much less daunting and helped me a lot during the term! It even cultivates in me a love for complex analysis! There are not a lot of intuitive videos on university math like what you did. I was so excited when I found your channel and I recommended these video to all of my friends after the term has started :) Genuinely thank you so much! ❤️

  • @nathanisbored
    @nathanisbored 2 года назад +48

    i watched to the end, i learned a lot of what i wanted to learn in this episode!!

  • @johnchessant3012
    @johnchessant3012 2 года назад +20

    Amazing! Really appreciate the effort you put into these videos, of course I watched to the end :)
    To add the details for the integral: The magnitude of the integrand exp(iz)/(z^2+1) on the semicircle of radius R is bounded by 1/(R^2-1) while the length of the semicircle is πR. So the integral on the semicircle is O(1/R), which goes to 0 as R -> infinity. The residue at z=i of the integrand is the limit of (z-i)exp(iz)/(z^2+1) as z -> i, which is exp(-1)/(2i). So the integral is 2πi times that, which is π/e. A lovely answer!

    • @mathemaniac
      @mathemaniac  2 года назад +3

      Thanks for providing the details here!

    • @josipfleis9223
      @josipfleis9223 2 года назад +2

      Back in the '80-es, I managed to solve those integrals, using this method of complex integration (I use a book emineter.files.wordpress.com/2016/03/kompleksna-analiza.pdf)
      Although I was quite "well trained" in this field of mathematics, I get fully understand this watching Your video!

  • @nicholasbohlsen8442
    @nicholasbohlsen8442 2 года назад +49

    22:35 I love seeing the multipole fields of electrodynamics appear as the Polya vector fields of the inverse powers. Its just such a cute connection between the multipole expansion and laurent series

    • @mathemaniac
      @mathemaniac  2 года назад +5

      Yes indeed! Though obviously in "the real world", we wouldn't see this connection very well, because we live in 3D!

    • @lifehope4201
      @lifehope4201 2 года назад

      @@mathemaniac Did you imagined everything before making this video or you visualised everything using software first .......?

  • @ativjoshi1049
    @ativjoshi1049 2 года назад +15

    This single video feels like a crash course on Complex Analysis

    • @mathemaniac
      @mathemaniac  2 года назад +7

      Yes, indeed that's the intention.

    • @ToriKo_
      @ToriKo_ 2 года назад

      Ur comment piqued my interest

  • @068LAICEPS
    @068LAICEPS 2 года назад +16

    I love everything related to Cauchy's mathematical topics. Now I love this Channel.

  • @abdullahalsakka
    @abdullahalsakka 2 года назад +11

    You are an amazing creator and I don't know how to thank you enough. I am a physics engineering student and I have been struggling so long to understand the intuition behind complex integrations. I can do them but unfortunately by memorizing how to do them, I was blown when I saw this simple intuitive video and I really want to thank you deep from my heart. Also as a side note, I really liked how you explained the complex integration using physical quantities like work and flux. Keep up the great work and I hope soon enough many people find this channel and explore the fun and intuitive sides of mathematics.

  • @samuelmarquardt7884
    @samuelmarquardt7884 2 года назад +8

    I love that the ads are between segments instead of annoying me while he's explaining

  • @ЕгорКут
    @ЕгорКут 2 года назад +9

    I am supposed to start studying complex analysis in nearly 1.5 years from now. But it's really nice to have some good intuitions before you fill in the details. Thanks for your video!

  • @vkv392
    @vkv392 2 года назад +6

    As a physics student....this blew my mind .....no words to convey my regards..thankyou very much for your effort..I was smiling out of pleasure whole thile time while watching your explanation...😌😌😌

    • @mathemaniac
      @mathemaniac  2 года назад +1

      Thanks for the kind words!

  • @daigakunobaku273
    @daigakunobaku273 2 года назад +16

    Your video is the best explanation of Cauchy's formula I've ever seen, and I've read this part in, like, three different textbooks. Please, continue with this series, it is damn good

    • @mathemaniac
      @mathemaniac  2 года назад +1

      Thanks for the compliment! However, as explained in the previous video (linked in the pinned comment), I would probably end this series, though it does not mean complex analysis will not appear on this channel, just maybe some occasional appearance rather than a series. Or to think of it this way, those topics are not "Essence of" anymore.

  • @mellamofields4275
    @mellamofields4275 2 года назад +3

    Such an amazing video, possibly one of the best vid of complex integration outhere, great job!
    Btw, is this inspirated on the book Visual Complex Analysys from Tristan?

    • @mathemaniac
      @mathemaniac  2 года назад +1

      Thanks for the compliment! I did say in the beginning of the video series that this entire series is inspired by that book.

    • @mellamofields4275
      @mellamofields4275 2 года назад

      Ohh, I only saw this video, I'll check the rest of the series when I have time.
      Hope one day I can animate my videos, as well as you, did in this one, 3B1B vibes here hehe, cya mate!😁

  • @YourLocalCafe
    @YourLocalCafe 2 года назад +6

    I am a highschooler so this went way over my head, but i must say that you are doing a great job at making these and you must keep at it!
    Your quality and the quantity with that kind of quality are both spectacular.
    Your channel is heavily underrated, but hey i am here!

  • @navjotsingh2251
    @navjotsingh2251 2 года назад +3

    Please go into more detail about the ending! You are doing the Lords work, the more videos you can make about complex analysis the more better humanity will be!

    • @mathemaniac
      @mathemaniac  2 года назад +1

      Thanks for the compliment! Though I would most likely not be uploading here even if I would go into the detail there - instead on my second channel.

    • @navjotsingh2251
      @navjotsingh2251 2 года назад +1

      @@mathemaniac either way, us students greatly appreciate any efforts, and I think you can become one of the best go to channels for complex analysis. It would be good if you could maybe in the future show how we can do computational complex analysis and maybe even show how complex analysis can be used to analyse the complex version of fourier transforms/fourier series. There are so many things that you can do to help us and make you become a golden channel!

  • @darwinbodero7872
    @darwinbodero7872 Месяц назад +1

    The hardest thing about complex analysis is proving the Jordan Curve Theorem

  • @sudhirfadnavis9312
    @sudhirfadnavis9312 2 года назад +4

    Thanks. I am electrical engineer studied engineering 4 decades back. This video seamlessly put all the maths concepts together.

  • @charlievane
    @charlievane 2 года назад +1

    movies like this one should be shown to school-children, beats any textbook by far

  • @journeytotheinfinity440
    @journeytotheinfinity440 Год назад +1

    there is an error in chapter 2 at the time stamp 9:38 .. Although you're adding up the angles between f(z) bar and dz which corresponds to the value theta but the animation on the first line didn't change alpha+beta to theta instead it was shown multiplied

  • @michaelbuckley5847
    @michaelbuckley5847 2 года назад +1

    Literally took this class last semester, WHERE WAS THIS VIDEO THEN

  • @genevievebrooks9605
    @genevievebrooks9605 2 года назад +2

    Watched the whole thing, it helped me enourmously the week before my complex analysis final!

  • @hydropage2855
    @hydropage2855 10 месяцев назад +1

    I learned another method to find residues first that I find more efficient. Taking the limit as z -> a of (z - a)f(z)

  • @angelespinosa906
    @angelespinosa906 2 года назад +3

    Que buen video, felicidades en mi caso lo relaciono con las leyes de Maxwell ojalá así me lo hubieran enseñado en mi clase de cálculo de la universidad, felicidades de nuevo.

  • @YOUSIFPOTATOYT0
    @YOUSIFPOTATOYT0 2 года назад +4

    This the one of the if not the best complex analysis explanations I've ever seen !, thank you for your efforts .

  • @michaelperrone3867
    @michaelperrone3867 2 года назад +5

    I remember seeing this in a mathematics class in college but with your explanation, I finally understand and appreciate what's going on here. Thanks! You're excellent at explaining things.

    • @mathemaniac
      @mathemaniac  2 года назад +1

      Thanks so much for the appreciation!

    • @michaelperrone3867
      @michaelperrone3867 2 года назад

      @@mathemaniac By the way, what's the software used here? Is this the same thing 3Blue1Brown uses? I'd like to learn how to use it for maths visualization for my own projects too; you should add a link to it in the video description or maybe to a sponsorship with them if it's a company.

  • @samuelthecamel
    @samuelthecamel 2 года назад +2

    Recently I made a simple integration program on my graphing calculator, and one day I was curious to see if it could do complex numbers. Turns out, it can! The specific contour is just the straight line path between a and b, which means it can't do most of the stuff from this video. But, the fact that it works is surprising enough.

    • @MasterHigure
      @MasterHigure 2 года назад +1

      Complex numbers really aren't that much of a step up from the real numbers. Surprisingly many things just work when you lift them up.

  • @camilo_murcia
    @camilo_murcia 2 года назад +1

    bro, I really appreciate this video, straight to the point and good explanantion

  • @kevincerda6636
    @kevincerda6636 2 года назад +4

    As someone who's never taken complex analysis, you make it so interesting and engaging to keep watching. I admit some lengthy videos can be intimidating and hard for me to understand, but something about this one made me watch it through the end. I really do feel like I learned a lot from it!

    • @mathemaniac
      @mathemaniac  2 года назад +1

      Really glad that you like the video!

  • @JackDespero
    @JackDespero 8 месяцев назад +2

    What i love about watching videos of "basic topics" that I already know, is that each person gives it a slightly different perspective, and I always learn a new nudget of knowledge, a new way to visualize or understand something.
    Thank you for the video.

  • @derickd6150
    @derickd6150 2 года назад +2

    Epic video 😁 glad you at least showed part of how it would be applied. I think a lot of what makes it so interesting is how you can solve a seeming unrelated integral like what you showed with cos there. I think seeing that is what will make people go look up more

  • @nerkulec
    @nerkulec 2 года назад +2

    Amazing! Every second of this video was well worth it, will surely rewatch it again to internalize all those ideas. Thank you!

  • @atomicgeneral
    @atomicgeneral Год назад +1

    Preserve your sanity! We are watching (to the end)!

  • @martintorres7408
    @martintorres7408 Год назад +2

    Very good video :)

  • @fernandojimenezmotte2024
    @fernandojimenezmotte2024 2 года назад +1

    Thank You for this really beautiful, very didactic and enjoyable video on Polya Vector Fields, Complex Analysis, Cauchy Riemman, Complex Integration, Vector Analysis. It would be great if You can create a Part II version continuation of this specific topic using Matlab + Simulink , Computing Symbolic Math and other CAD tools with applications. [Engineering, Physics, Quantum Physics, Chemistry, etc...].

  • @betacenturion237
    @betacenturion237 2 года назад +2

    Hey Mathmaniac,
    I'm taking a graduate level mathematical methods for physics class and we are currently going over this. I can't begin to explain how helpful this video has been in trying to understand the content of complex analysis and I wish I saw this sooner! Thank you!

  • @mastershooter64
    @mastershooter64 2 года назад +2

    40 mins??? the gods have blessed us with more amazing content bois!!

  • @oldsachem
    @oldsachem 2 года назад +2

    Best thesis explanation of calc stated in the first minute I've ever heard.

  • @pendragon7600
    @pendragon7600 2 года назад +2

    whew, new mathologer video and new mathemaniac video in the same day. excellent

    • @mathemaniac
      @mathemaniac  2 года назад

      Haha it just so happened that we both upload on the same day.

  • @aldobernal1684
    @aldobernal1684 2 года назад +3

    I study physics and this play list helped to understand my semester of complex analysis, it was really nice/cool to understand better what those excercises were about 😂

  • @jacobhoward7579
    @jacobhoward7579 2 года назад +1

    I've been waiting for this video for ages... I do not have the time to watch it at the moment but I wanted to comment immediately for the algorithm...
    Again, if you've read my personal comment to you... Thank you ... Thank you again 🙏

    • @mathemaniac
      @mathemaniac  2 года назад

      Hope that you will enjoy it!

  • @TimDuncanofSoccer
    @TimDuncanofSoccer 2 года назад +1

    Wow, this is a great intro to complex analysis

  • @XusermrX
    @XusermrX 2 года назад +1

    I'm still here, pleas do more videos like this one!

  • @butchtoughman2376
    @butchtoughman2376 2 года назад +2

    This is absolutely phenomenal, thank you so much for your work!

  • @goodplacetostop2973
    @goodplacetostop2973 2 года назад +2

    I’ve watched until the end. Really great content… How have I not subscribed before?!

    • @mathemaniac
      @mathemaniac  2 года назад +1

      Thanks for watching till the end!

  • @lourencoentrudo
    @lourencoentrudo 2 года назад +2

    You've outdone yourself. Superbly presented!

  • @riyannaffanusafara5940
    @riyannaffanusafara5940 6 месяцев назад +1

    Come for Cauchy, left with "I am going to math olympiad". I might not understand the half of the video, yet, but I will harness the power of complex analysis to its fullest. I'm going to get a hundred 💯

  • @fifaweed1311
    @fifaweed1311 2 года назад

    The person speaking makes this 150% more intresting & understandable

  • @carlosquesada5900
    @carlosquesada5900 2 года назад +1

    Well, I had my final complex analysis test last Monday, so watching this video right now is a nonsense for me hahahah. However, it's an amazing video. I never understood why the residue is a_(-1) until now. Thank you!!

  • @KOMATH
    @KOMATH 2 года назад +1

    I love every bit of this video! Absolutely amazing!

  • @joaofrancisco8864
    @joaofrancisco8864 2 года назад +1

    Hey, I watched it till the end! When it was over, I hadn't even realized 40 minutes had passed. I wish you had done the last caculations!

    • @mathemaniac
      @mathemaniac  2 года назад

      Thanks so much for staying till the end!

  • @roeesi-personal
    @roeesi-personal 2 года назад +2

    Got to 40:00

  • @michaelhall6187
    @michaelhall6187 9 месяцев назад +1

    Getting ready to take a course on complex analysis in the next semester and youtube recommended this video to me, very helpful and simply explained so I’m much more confident now about the class! Thanks for the great video 😄

  • @ganyahsoldier7199
    @ganyahsoldier7199 2 года назад +2

    Thank you for the video, it helped me so much :)

    • @mathemaniac
      @mathemaniac  2 года назад +1

      Glad it helped!

    • @ganyahsoldier7199
      @ganyahsoldier7199 2 года назад

      @@mathemaniac are you going to do the continuation of this one ?

  • @yfidalv
    @yfidalv 2 года назад +2

    I watched till the end :) This video made me even more excited for when I’ll take complex analysis in college, really enjoyable!

    • @mathemaniac
      @mathemaniac  2 года назад

      Thanks so much! Not many people will watch till the end!

  • @amaanabbasi280
    @amaanabbasi280 2 года назад +2

    Keep making videos like this

    • @mathemaniac
      @mathemaniac  2 года назад +1

      Thanks for the kind words!

  • @0theblackdragon
    @0theblackdragon 5 месяцев назад +1

    Nice video, i watch to the end

  • @arttrust7629
    @arttrust7629 2 года назад +1

    Really thank you 🙏, from India.
    I completed my M. Sc in mathematics. Your contents are helping me.

  • @js7244
    @js7244 2 года назад +1

    Thanks for the video! amazing content and insight in to complex integration!

  • @josenegrete9876
    @josenegrete9876 2 года назад +1

    I have watched the whole video :)

  • @ChrisMazzerbo
    @ChrisMazzerbo 2 года назад +1

    I've been trying to work on complex integration for a couple days now, and I got stuck so I checked if I could find a video somewhere (I didn't remember 3B1B making any in depth video about this topic so I thought I'd look elsewhere).
    Seriously, this is explained really clearly and I couldn't have hoped for better contebt than this, it's reall been motivating me to work more on all this.
    I've been going through your other videos and there are gems that are definitely worth subscribing for! (the geometric interpretation of sin(x)'s Taylor series really surprised me, I've been working with it for years and never would have seen that coming)

  • @mehulborad2400
    @mehulborad2400 2 года назад +1

    Hello there I watched to the end! It was the most intresting! I look forward to more videos like this

  • @Elaine-y4c
    @Elaine-y4c 2 года назад +1

    Thank you a lot for this brilliant video. I have finished the whole list. It very well presented and I can understand the elegancy of complex analysis as a beginner with no background knowledge.

  • @arminiouz
    @arminiouz 2 года назад +1

    Bro love your videos. Keep it up 👍🏼 I stayed until the end.

    • @mathemaniac
      @mathemaniac  2 года назад +1

      Thanks for sticking around till the end :)

  • @rubenquirozmarnef8119
    @rubenquirozmarnef8119 2 года назад +1

    Hi! I’ve got exam of complex analysis the day after tomorrow. Your video really helped to clear things up, thanks! But I don’t like the cosine example because this is one where the infinite arc part doesn’t disappear and you need the extra trick by using de moivre…

    • @mathemaniac
      @mathemaniac  2 года назад +2

      Glad it helps! But the arc part does disappear! The estimation lemma already works to say that the integral on the arc goes like 1/R, which goes to 0. If you have learnt it, Jordan's lemma would make this part a lot easier!

    • @rubenquirozmarnef8119
      @rubenquirozmarnef8119 2 года назад

      @Mathemaniac What I meant is that you have to be smart and change the cosine into the exponential function because trying to integrate the cosine directly doesn’t work. Or does it? When I tried it naively I got e^-1 +e in stead of the correct 1/e

  • @depressedguy9467
    @depressedguy9467 2 года назад +1

    You write iota× flux there but iota is already contained in flux then how

    • @mathemaniac
      @mathemaniac  2 года назад +1

      The flux should be just the integral of the dot product - the vector involving i just means the direction of that complex number.

  • @charlynys4821
    @charlynys4821 2 года назад +2

    Pi/e

  • @Noemi.39
    @Noemi.39 2 года назад +1

    Yours are some very rare and precious video, i admire you.

  • @General12th
    @General12th 2 года назад +1

    This is a great video with a great ending. I watched all the way through!

  • @vahehawi9503
    @vahehawi9503 2 года назад +1

    Exactly what I needed in order to fully understand the concept... It's amazing !!

  • @antonioe.2396
    @antonioe.2396 2 года назад +1

    wow i had an exam on this last month, this could've helped me get a few extra points lol good vid

  • @sagarjc5423
    @sagarjc5423 2 года назад +1

    Thanks for explaining so well. I hope there are many more videos on complex integration

  • @edilmolinafernandez7670
    @edilmolinafernandez7670 Год назад +1

    I se the video útil the end

  • @m.s.1766
    @m.s.1766 2 года назад +1

    comment for sanity ^^

  • @juanfranciscocanesesmarin7086
    @juanfranciscocanesesmarin7086 2 года назад +1

    Watched the whole thing! awesome video on complex analysis

  • @paominlienguite2397
    @paominlienguite2397 2 года назад +1

    I am soooo impressed with uour teaching I super like it.

  • @__erroneous__
    @__erroneous__ 2 года назад +1

    Yes i watched it whole

  • @jainilpatel8078
    @jainilpatel8078 Месяц назад +1

    Really nice 👌

  • @15ghostrunnindeaththrowsha31
    @15ghostrunnindeaththrowsha31 2 года назад

    ghostrunnindeaththrowshadows 🥃🥃🐝🐝 chile in the desert panama//storm 🎹🎹🎹 london40

  • @shinjirigged
    @shinjirigged 2 года назад +1

    I love when we make sure that we get the small assumptions right. Thank you, and Bravo!

  • @xulq
    @xulq 2 года назад +1

    watched all the way to the end so you can keep your sanity! ;)

  • @francepaguia2100
    @francepaguia2100 5 месяцев назад +1

    thank you so much

  • @erictao8396
    @erictao8396 2 года назад +1

    Really cool video :) Never saw these things explained in terms of the Pólya vector field before

    • @mathemaniac
      @mathemaniac  2 года назад +1

      That's why I made this video! The Pólya vector field makes this way more visual!

  • @anguswu2685
    @anguswu2685 2 года назад +1

    watched till the end! just learned it last term in second year electrical/computer engineering but it’s so refreshing to see it with graphics

  • @adireddisrinivas8868
    @adireddisrinivas8868 2 года назад +1

    Thank you so much!!

  • @angeldude101
    @angeldude101 2 года назад

    I thought Polya vector fields looked fishy, but seeing the dot product added to an imaginary cross product revealed why. Nowadays, when I see a dot and cross product together, I immediately think of the geometric product. Treating the complex numbers like GA complex numbers in G(2), converting to a Polya vector field seems equivalent to converting from a complex number to a normal vector by right-multiplying by the x-axis unit vector. To be clear, the geometric product between two GA complex numbers (or GA quaternions in G(3)) is identical to normal complex multiplication, while the geometric product between two vectors gives a complex number (in G(2)). So... ∫f(z)dz = ∫∇FdA = Work + iFlux

  •  2 месяца назад

    Absolutely amazing video. Any following planed? For instance, on analytic continuation : )

  • @蒋正-k6u
    @蒋正-k6u 2 года назад +1

    wow!!! ur video is ******* beautiful and intuitive!!!!

  • @carmelpule8493
    @carmelpule8493 5 месяцев назад

    I followed this video to the end and it is a wonderful video, . I am an engineer and I see this contour integration as follows.
    If one is integrating (1/z)*dz and z is taken as z= e^j(theta) then 1/z= e^(-j)(theta) and dz= je^j(theta). d(theta)
    Basically these are vectors rotating in the clockwise and anticlockwise direction.
    If the numerator is rotating in the same direction as the denominator there will be no resulting rotation of (1/z) dz and the vector integral will be along a line. the same length as the circumference = 2 pi. . with the j included because of the derivative.
    If the numerator is not rotating at the same rate as the denominator then the final equation will rotate and so its integral is zero.
    It is all a beautiful engineering operation and in the case of (1/(z-a)) dz then at location a it is the only expression that does not rotate and all the other location will rotate because of dz rotating. when z= a +e^j(theta) . At location a the function (1/(z-a)) dz is not rotating but all the others a other " poles b,c, d etc. are rotating so their integral is equal to zero.
    In other cases there are the residues to care for.
    The same for (1/(z-a)) dz and
    (1/(z-a)^n) dz

  • @黄冬郁
    @黄冬郁 3 месяца назад

    Very impressive video! For the discussion in Chapter 6, may I say that, only charge matters, and those integrals around dipoles or quadrupoles and so on will vanish. That's quite interesting and is there any related physics in this?

  • @jaimeafarah7445
    @jaimeafarah7445 Год назад

    Nice video !
    ‘though it's important to point out (at 8:00) that the cross product results a vector (not a scalar).
    ∇ × ( iu − jv ) = −k(∂v/∂x + ∂u/∂y)
    if ∇ × ( iu − jv ) = 0 then ∂v/∂x = −∂u/∂y

  • @simonavarne9635
    @simonavarne9635 2 года назад +1

    I'm still here and enjoying the excellent video

  • @Zonox-ml4jq
    @Zonox-ml4jq Год назад

    I have a doubt... I want to find areas of regions between certain points in a complex plane (imagine a grid) that is transformed. Because I want to compare euclidian areas to transformed areas by a certain holomorphic function. How can I do it? I mean if a function is holomorphic the area will be cero because of Cauchy's theorem, right? Then, how I calculate this areas. I am thinking about functions like e^z. Someone has any ideas?

  • @sharpnova2
    @sharpnova2 2 года назад

    "If you are wondering how I made all these videos, even though it is stylistically similar to 3Blue1Brown, I don't use his animation engine Manim, but I will probably reveal how I did it in a potential subscriber milestone, so do subscribe!"
    Hmm... I'm not a fan of this. Either reveal it right there where you were talking about it or don't talk about it at all. Don't dangle it like that.
    I will currently assume you are using 3b1b's engine since it looks similar.
    Great coverage of this topic btw.

  • @Miguelocod
    @Miguelocod Год назад

    Its' 4 AM and I've just watched the whole 40 mins. I had complex analysis for electrical engineering course and it was the hardest, and I never understood anything of it, residues and countours just feeled magical. Until this video.