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

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  • เผยแพร่เมื่อ 30 ม.ค. 2025

ความคิดเห็น • 77

  • @juniorcyans2988
    @juniorcyans2988 ปีที่แล้ว +4

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

  • @pizzacrust7029
    @pizzacrust7029 ปีที่แล้ว +14

    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 2 ปีที่แล้ว +16

    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

    • @MyOnlyMaster
      @MyOnlyMaster 3 หลายเดือนก่อน

      Get your son into the university of washington

    • @brendawilliams8062
      @brendawilliams8062 3 หลายเดือนก่อน

      Proof that first come is motivation

  • @ItsDeveshA
    @ItsDeveshA 9 หลายเดือนก่อน +2

    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 :)

  • @Cindsardella
    @Cindsardella ปีที่แล้ว +5

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

  • @dennerguilhon
    @dennerguilhon ปีที่แล้ว +33

    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 ปีที่แล้ว

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

  • @JAYasankarPillai7
    @JAYasankarPillai7 ปีที่แล้ว +2

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

  • @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.

  • @ViridiansVivarium
    @ViridiansVivarium 10 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!!

  • @mehmet2247
    @mehmet2247 ปีที่แล้ว +2

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

  • @lucapetrescu6990
    @lucapetrescu6990 8 หลายเดือนก่อน +1

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

    • @XJWill1
      @XJWill1 8 หลายเดือนก่อน +1

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

  • @nokidding152
    @nokidding152 ปีที่แล้ว +1

    That intro is awesome!!

  • @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 ปีที่แล้ว +1

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

  • @ericchasseur3904
    @ericchasseur3904 9 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.

  • @dansantner
    @dansantner ปีที่แล้ว +1

    Outstanding. Love your videos.

  • @xinglinli9874
    @xinglinli9874 2 ปีที่แล้ว +3

    Saving me so much time.

  • @fanwellnyereyemhuka8378
    @fanwellnyereyemhuka8378 2 หลายเดือนก่อน +1

    You are an amazing lecturer sir.I need more of these.You make my life easier.Keep it up.

  • @vahdan97
    @vahdan97 ปีที่แล้ว

    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!

  • @curtpiazza1688
    @curtpiazza1688 10 หลายเดือนก่อน

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

  • @AnirbanMukhopadhyayeed
    @AnirbanMukhopadhyayeed ปีที่แล้ว +1

    Thank you for such informative lecture.

  • @andrcarb
    @andrcarb 9 หลายเดือนก่อน

    This is a great video, good job!

  • @fabdelap2971
    @fabdelap2971 ปีที่แล้ว

    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 10 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 10 หลายเดือนก่อน

      Correct me if I'm wrong tho

  • @abelmedina-aispuro3716
    @abelmedina-aispuro3716 11 หลายเดือนก่อน

    What a beautiful 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.

  • @RobertCantwell-z1n
    @RobertCantwell-z1n หลายเดือนก่อน

    Why isn’t the natural log ( ln ) being use here instead of “ log ? “

  • @killoffman
    @killoffman 6 หลายเดือนก่อน

    What an ABSOLUTE legend!

  • @abelmedina-aispuro3716
    @abelmedina-aispuro3716 11 หลายเดือนก่อน

    Great lecture

  • @thegodofhpyixel
    @thegodofhpyixel หลายเดือนก่อน +1

    He is left handed as right handed cross their hand with body symmetry line while writing

  • @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?

  • @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 🙏

  • @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 ปีที่แล้ว

      it depends on the direction of the rotation

  • @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.

  • @belwizdadimed3967
    @belwizdadimed3967 11 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.

  • @copernicus6420
    @copernicus6420 11 หลายเดือนก่อน

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

  • @stevenzhang5294
    @stevenzhang5294 11 หลายเดือนก่อน

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

  • @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.

  • @jimlbeaver
    @jimlbeaver ปีที่แล้ว

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

  • @antonzub672
    @antonzub672 ปีที่แล้ว

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

  • @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

    • @brendawilliams8062
      @brendawilliams8062 3 หลายเดือนก่อน

      Professor Norman Wildberger can reach Cauchy or closed intervals formulas if you live triangles

  • @extendedwhizz1637
    @extendedwhizz1637 10 หลายเดือนก่อน

    3:15 , 17:17

  • @QetyzPsn
    @QetyzPsn ปีที่แล้ว

    🤯 math is so cool

  • @radadadadee
    @radadadadee 8 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.

    • @epicchocolate1866
      @epicchocolate1866 2 หลายเดือนก่อน

      That is false. That is the definition of a “single valued function”

    • @radadadadee
      @radadadadee 2 หลายเดือนก่อน

      @@epicchocolate1866 check out Wolfram's entry and you'll realize that there is no such thing as a multi-valued function. The word "function" there is a misnomer perpetuated by morons like you and your kind.

  • @emir2750
    @emir2750 4 หลายเดือนก่อน

    fucking great lesson mate

  • @zrmsraggot
    @zrmsraggot ปีที่แล้ว

    Real life application of that please ?

    • @Exoepxoe
      @Exoepxoe ปีที่แล้ว

      rlc circuits

  • @sarkarsubhadipofficial
    @sarkarsubhadipofficial ปีที่แล้ว

  • @뾱뾱-c9n
    @뾱뾱-c9n ปีที่แล้ว +2

    칠판 신기하다

    • @Exoepxoe
      @Exoepxoe ปีที่แล้ว

      화이트보드보다 훨씬 낫네요

    • @comment8767
      @comment8767 ปีที่แล้ว

      @@Exoepxoe 화이트보!!!

    • @Exoepxoe
      @Exoepxoe ปีที่แล้ว

      @@comment8767 아니요, 검은색 보드 같지만 흰색이에요.

    • @comment8767
      @comment8767 ปีที่แล้ว

      @@Exoepxoe Αγαπώ την Ελλάδα

    • @Exoepxoe
      @Exoepxoe ปีที่แล้ว

      @@comment8767 Κι εγώ, αγαπώ πολύ την Ελλάδα.

  • @lessnightlights8535
    @lessnightlights8535 ปีที่แล้ว

    the marker sqeak is unbearable 😢

  • @asmithgames5926
    @asmithgames5926 6 หลายเดือนก่อน

    Did anyone notice he's writing BACKWARDS???