Complex Analysis L04: The Complex Logarithm, Log(z)

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ความคิดเห็น • 69

  • @dennerguilhon
    @dennerguilhon ปีที่แล้ว +31

    I'm immensely amazed on his ability to write like this 👏👏

    • @andrewrezendes
      @andrewrezendes ปีที่แล้ว +9

      🤦 He reflects the camera image.

    • @ralphhebgen7067
      @ralphhebgen7067 ปีที่แล้ว +2

      Yes! That also amazed me no end until I understood that people write normally on a glass pane and film it from behind! I am still amazed he can write like this, though - the maths is lucid and clear! 😂

    • @abrlim5597
      @abrlim5597 ปีที่แล้ว +1

      I still don't understand how this works

    • @jasonthomas2908
      @jasonthomas2908 ปีที่แล้ว +2

      @@abrlim5597 It's as Andrew said, he reflects the image along the vertical axis.

    • @ShengceZhang-wj9pp
      @ShengceZhang-wj9pp 11 หลายเดือนก่อน

      which implies he is writing by left hand. Still impressive for me@@jasonthomas2908

  • @pizzacrust7029
    @pizzacrust7029 11 หลายเดือนก่อน +9

    My professor is not good at getting any of this information across, he's incredibly intelligent, but is very bad at teaching. Your video taught me more in thirty minutes than i learned in multiple lectures. Thank you for the work you put out, it's really made a huge difference in my understanding of complex analysis!!!!

  • @andreacomparini9381
    @andreacomparini9381 ปีที่แล้ว +13

    I wish you were the teacher of my son. Really great lessons. My compliments

    • @Chetan_Hansraj
      @Chetan_Hansraj ปีที่แล้ว +1

      Yes I wish he was my teacher too ..

    • @hoseinzahedifar1562
      @hoseinzahedifar1562 ปีที่แล้ว

      @@Chetan_Hansraj me too. he is a great teacher👍👍

    • @rob4187
      @rob4187 ปีที่แล้ว +1

      He is teaching you through these videos

  • @juniorcyans2988
    @juniorcyans2988 ปีที่แล้ว +2

    I just found this channel last night, and I couldn’t keep me away from it😅What a surprising treasure I found luckily!

  • @Cindsardella
    @Cindsardella ปีที่แล้ว +4

    I am amazed! Took me a while to find this, thank you! Really great to follow 😀

  • @ItsDeveshA
    @ItsDeveshA 5 หลายเดือนก่อน +1

    Damn-I had done this topic in my college and there-we were explained a bit and given the formula. But your video literally made me fall in love with the Beauty of Mathematics. I genuinely feel that the professors that bring life to the Subject should be the only ones allowed to teach-else, you kill the LOVE FOR THE SUBJECT and eventually students end up hating the subject(where in reality, they hated to just mug the things up and see it all superficially).
    Thanks for the video Steve :)

  • @mehmet2247
    @mehmet2247 ปีที่แล้ว +2

    I felt like "from zero to hero" in this video, thanks a lot

  • @JAYasankarPillai7
    @JAYasankarPillai7 ปีที่แล้ว +2

    Thanks a lottttttttt for uploading, I requested for this video the other day. impressively prompt........appreciate it,

  • @ViridiansVivarium
    @ViridiansVivarium 6 หลายเดือนก่อน

    Thank you!! This was so fun and informative, and has really helped give an intuition for something I've been struggling with. Merci beaucoup!!

  • @xinglinli9874
    @xinglinli9874 ปีที่แล้ว +3

    Saving me so much time.

  • @dansantner
    @dansantner ปีที่แล้ว +1

    Outstanding. Love your videos.

  • @AnirbanMukhopadhyayeed
    @AnirbanMukhopadhyayeed ปีที่แล้ว +1

    Thank you for such informative lecture.

  • @curtpiazza1688
    @curtpiazza1688 7 หลายเดือนก่อน

    Wow! Cool stuff! The graphs and pictures are so helpful! 😂

  • @ralphhebgen7067
    @ralphhebgen7067 ปีที่แล้ว

    Perfect - many thanks for that lucid and clear explanation. The only thing I would have liked to have added is the notation “arg(z)” and “Arg(z)”, which is often used. It’s clear enough what that is from the video, though.

  • @abelmedina-aispuro3716
    @abelmedina-aispuro3716 7 หลายเดือนก่อน

    What a beautiful lecture

  • @killoffman
    @killoffman 2 หลายเดือนก่อน

    What an ABSOLUTE legend!

  • @andrcarb
    @andrcarb 6 หลายเดือนก่อน

    This is a great video, good job!

  • @annanor9009
    @annanor9009 ปีที่แล้ว +2

    Thank you so much for these videos!
    The word "branches" in this context feels very strange to me. When I hear "branches," I imagine a tree-like structure, where there are junctions that have multiple choice of "direction" to go in, whereas the branches as illustrated here appear to be segments of a continuous spiral.

    • @JamesMartin-vn5dq
      @JamesMartin-vn5dq 11 หลายเดือนก่อน +1

      maybe we should call them 'cliffs', because you fall all the way from Pi to -Pi

  • @nokidding152
    @nokidding152 ปีที่แล้ว

    That intro is awesome!!

  • @vahiddanesh4661
    @vahiddanesh4661 9 หลายเดือนก่อน

    What my professor couldn't teach us in 10+ lectures, you just taught in 30 minutes. I wish I see you one time in-person!

  • @abelmedina-aispuro3716
    @abelmedina-aispuro3716 7 หลายเดือนก่อน

    Great lecture

  • @jamesjohn2537
    @jamesjohn2537 ปีที่แล้ว

    Nice lectures, am a self studying student of calculus, studying calculus II, and this lectures complex analysis start making sense to that of powers series, trig. functions more of lower math I learned a long the way. kind of nice and keep my motivative of why learning calculus! thanks sir.

  • @ericchasseur3904
    @ericchasseur3904 6 หลายเดือนก่อน

    At 26:00. I think there is a mistake here. What for sure is correct is : integral of 1/z dz = 2*pi*i on a closed contour around z=0. However, integral of Log(z) dz on a circle arond z=0 where it makes sense (with complex numbers with phase in ]-pi,pi[, excluding the values -pi and pi because Log is not defined on negative real numbers) = - 2*pi*i. With a negative sign.

  • @Chetan_Hansraj
    @Chetan_Hansraj ปีที่แล้ว +3

    Thank you soo much for this , just One suggestion the overall master volume of the video is quite low , would be great if it's a bit louder . Thanks 🙏

  • @fabdelap2971
    @fabdelap2971 9 หลายเดือนก่อน

    Sir. The log you are using is the log base e and is usually written as Ln. In France we call it the "natural logarithm". So it is certainly not restricted to the complex numbers.

    • @samuelahibo339
      @samuelahibo339 6 หลายเดือนก่อน

      Yes but I think what he means is that Ln is used more with real numbers and Log with complex numbers,
      I remember my "Lycée" teacher saying that "log" with lower case l, is the logarithm that we know with any base (or 10), and "Log"
      Upper case L is usually use to mean base e or "logarithme népérien"

    • @samuelahibo339
      @samuelahibo339 6 หลายเดือนก่อน

      Correct me if I'm wrong tho

  • @lucapetrescu6990
    @lucapetrescu6990 4 หลายเดือนก่อน

    not only is this man capable of explaining complex analysis, but he can also write backwards 🤯🤯🤯. What a guy

    • @XJWill1
      @XJWill1 4 หลายเดือนก่อน +1

      Or he is just left-handed (or capable of writing with his left hand). Easy to reverse the video.

  • @belwizdadimed3967
    @belwizdadimed3967 7 หลายเดือนก่อน +1

    If f is a function defined from set E to set F which is f: E -> F , we know by definition that each x in E has at most one picture in F. How come you call a function an object that associates one value from E to an infinite values in F??? You should restrict to the principal to call the complex log a function. May be you can define an infinite sequence of functions fn indexed by integer n. Per Bourbaki consistency is key in mathematics not in physics.

  • @jimlbeaver
    @jimlbeaver ปีที่แล้ว

    Wondering if this is the genesis of uncertainty between time and s-space…hmm 🤔..will wait and see. Thanks!

  • @copernicus6420
    @copernicus6420 7 หลายเดือนก่อน

    Shouldn't we dealing with ln since the logarithm are according to e ?

  • @stevenzhang5294
    @stevenzhang5294 7 หลายเดือนก่อน

    should the last plot of spiral start from x axis, rather than the y axis

  • @gabrielchircu422
    @gabrielchircu422 ปีที่แล้ว

    We know that |z| can be found by Pythagoras' theorem and is uniquely defined. However, Log(z) has a constant real component log(R), i.e. log(|z|), whereas the imaginary component jumps in steps of 2pi. What is then |Log(z)|? It looks as tough it varies according to the phase of Log(z) therefore it has an infinite number of values. Where is the contradiction?

  • @emir2750
    @emir2750 3 วันที่ผ่านมา

    fucking great lesson mate

  • @Impatient_Ape
    @Impatient_Ape ปีที่แล้ว

    Steve, is your background painted with something like Vantablack, Musou Black, or Black 3.0? I can't see any edge artifacts from using a green screen technique, so it got me wondering.

  • @QetyzPsn
    @QetyzPsn 10 หลายเดือนก่อน

    🤯 math is so cool

  • @Saweera786
    @Saweera786 ปีที่แล้ว

    Hello sir, could you please make a video of any particular algorithm that is used for acceleration signals affected by excitation sources and low frequency components in the streaming environment.

  • @antonzub672
    @antonzub672 ปีที่แล้ว

    Can you make one about residue theorem? (I am struggling with Matsubara Green’s functions)

  • @lamdawave
    @lamdawave ปีที่แล้ว

    Question 15:40
    One question Sir, can we also go in the negative direction by specifying the phase angle to be theta - 2 pi, theta - 4pi etc?

    • @Exoepxoe
      @Exoepxoe 10 หลายเดือนก่อน

      it depends on the direction of the rotation

  • @extendedwhizz1637
    @extendedwhizz1637 6 หลายเดือนก่อน

    3:15 , 17:17

  • @radadadadee
    @radadadadee 4 หลายเดือนก่อน

    There is no such thing as a "multi-valued function". "In mathematics, a function from a set X to a set Y assigns to each element of X exactly one element of Y". EXACTLY ONE. The example you gave about +/- in the square root, are the solutions to the corresponding equation. And by the way, the symbol for square root is ONLY for the positive result.

  • @뾱뾱-c9n
    @뾱뾱-c9n ปีที่แล้ว +2

    칠판 신기하다

    • @Exoepxoe
      @Exoepxoe 10 หลายเดือนก่อน

      화이트보드보다 훨씬 낫네요

    • @comment8767
      @comment8767 9 หลายเดือนก่อน

      @@Exoepxoe 화이트보!!!

    • @Exoepxoe
      @Exoepxoe 9 หลายเดือนก่อน

      @@comment8767 아니요, 검은색 보드 같지만 흰색이에요.

    • @comment8767
      @comment8767 9 หลายเดือนก่อน

      @@Exoepxoe Αγαπώ την Ελλάδα

    • @Exoepxoe
      @Exoepxoe 9 หลายเดือนก่อน

      @@comment8767 Κι εγώ, αγαπώ πολύ την Ελλάδα.

  • @shawnyao7850
    @shawnyao7850 ปีที่แล้ว

    can someone explain the 2 * pi * i in 24:49? I understand the 2*pi makes a circle, but how did the i appear?

    • @shawnyao7850
      @shawnyao7850 ปีที่แล้ว

      I guess Steve's intentionally leaving a lot of blanks on complex integrals and skipping to the end result of CIF. Will stay tuned until I read the latter part of the series haha

  • @sarkarsubhadipofficial
    @sarkarsubhadipofficial ปีที่แล้ว

  • @zrmsraggot
    @zrmsraggot ปีที่แล้ว

    Real life application of that please ?

    • @Exoepxoe
      @Exoepxoe 10 หลายเดือนก่อน

      rlc circuits

  • @asmithgames5926
    @asmithgames5926 2 หลายเดือนก่อน

    Did anyone notice he's writing BACKWARDS???

  • @lessnightlights8535
    @lessnightlights8535 ปีที่แล้ว

    the marker sqeak is unbearable 😢