what is the area of this Neumann Oval ?

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  • เผยแพร่เมื่อ 28 ม.ค. 2025

ความคิดเห็น • 52

  • @ojasdeshpande7296
    @ojasdeshpande7296 2 ปีที่แล้ว +4

    Can you tell me the name of a technique for integration which goes:
    1)notice a part of the integrand as an antiderivative of a function.
    2) that function turns out to be a geometric series
    3) integration and summation order are changed( idk the rules for that)
    Then the integral becomes easy

    • @drpeyam
      @drpeyam  2 ปีที่แล้ว +1

      Never heard of it

  • @adamfilipkalle
    @adamfilipkalle 2 ปีที่แล้ว +3

    I am always fascinated when you as a expert start to rev up your matematik engine.
    I understood maybe 3% of this whole section, purely because my matematik skill isn't on this level. Though I still find it enjoyable to watch.

    • @drpeyam
      @drpeyam  2 ปีที่แล้ว

      Thanks so much!!

  • @luggepytt
    @luggepytt 2 ปีที่แล้ว +3

    @3:28: “... times a polar thing which is ARRR dr dθ”
    - But where does the “ARRR” come from in polar coordinates?
    - Well, polar coordinates are circular, so it’s because of the 𝝅-rate!

    • @drpeyam
      @drpeyam  2 ปีที่แล้ว +1

      Nice 😂😂

  • @gregsarnecki7581
    @gregsarnecki7581 2 ปีที่แล้ว +3

    So the area (of a circle) that is ~π^2 now has an area under the transformation ~π. How did we lose a factor of π? That is pretty amazing! I think the fundamental reason for this is worth exploring/detailing/creating a video for.

    • @dlevi67
      @dlevi67 2 ปีที่แล้ว +5

      The area of a circle is ~π, the squaring is of the radius. No factor was harmed during this transformation.

  • @paradoxica424
    @paradoxica424 2 ปีที่แล้ว +7

    but doesn’t this only work if the region is a bijection? it is not immediately obvious that the Neumann Oval is a non-singular transformation of the unit disk…

    • @Test-zd4mp
      @Test-zd4mp 2 ปีที่แล้ว +1

      It should be a c1 diffeomorphism right?

  • @aneeshsrinivas9088
    @aneeshsrinivas9088 2 ปีที่แล้ว +1

    what do you mean, this is the transformation of the unit disk under the mapping z+z^2/2. the unit disk is r*e^(it) for 0

    • @drpeyam
      @drpeyam  2 ปีที่แล้ว +1

      It’s not a cardioid

    • @knivesoutcatchdamouse2137
      @knivesoutcatchdamouse2137 2 ปีที่แล้ว +1

      You need to set r=1 rather than varying it from 0 to 1, that may help.

    • @aneeshsrinivas9088
      @aneeshsrinivas9088 2 ปีที่แล้ว

      @@knivesoutcatchdamouse2137 i did and still got the same shape

  • @eduardojtu6501
    @eduardojtu6501 2 ปีที่แล้ว +6

    In the explanation of the Jacobian, there is a missing step at the end.
    From the Cauchy-Rieman equations, we have that:
    |det(Df)|=(uₓ)²+(uᵧ)²=(uₓ)²+(vₓ)²
    And also it is known that:
    f'(z)=df/dz=∂f/∂x=uₓ+ivₓ
    So, f'(z)=uₓ+ivₓ and we can see that:
    f'(z)*f̄'(z)=|f'(z)|=(uₓ)²+(vₓ)²=|det(Df)|

    • @drpeyam
      @drpeyam  2 ปีที่แล้ว +3

      Missing step?

    • @leif1075
      @leif1075 2 ปีที่แล้ว +1

      @@drpeyam Alsp why do you say that is usually all gibberish the Jacobian? It's not though at least mostly though? Can you clarify?

  • @spazmoidectomorf6209
    @spazmoidectomorf6209 2 ปีที่แล้ว

    Hello there, I am keen to learn these sorts of problems, what do I need to learn to get there?

  • @proxagonal5954
    @proxagonal5954 2 ปีที่แล้ว +3

    Hey Peyam! Love your videos. I am just nearing the end of multivariable calculus and while watching this video I recognised many concepts with equivalents in MC. So my question is: Is multivariable calculus and complex analysis just different ways to describe the same ideas? are their applications/results similar?
    Thank you!!

    • @drpeyam
      @drpeyam  2 ปีที่แล้ว +2

      Fundamentally they are different but there are lots of topological connections, mainly because of the (x,y) to x + iy similarity

    • @Noam_.Menashe
      @Noam_.Menashe 2 ปีที่แล้ว +1

      I am not a doctor in mathematics, I don't know too much, but complex space is like multivariable calculus but with multiplication and division defined as (x+iy)*(a+ib)=xa-yb+i(bx+ya)

    • @proxagonal5954
      @proxagonal5954 2 ปีที่แล้ว +1

      @@drpeyam Okay, Thank you!! Love your content man keep doing what you're doing.

    • @drpeyam
      @drpeyam  2 ปีที่แล้ว

      Thanks so much!!

  • @adrianyaguar7666
    @adrianyaguar7666 2 ปีที่แล้ว +2

    Really cool 😎

  • @kevincardenas6629
    @kevincardenas6629 2 ปีที่แล้ว +2

    Do the area of a Cassini oval please! :p Nice video btw!

  • @silvermica
    @silvermica 2 ปีที่แล้ว +2

    Wait. You're from Berkeley? Or UCI? I know a scientist at UCI.

    • @drpeyam
      @drpeyam  2 ปีที่แล้ว +2

      Both lol

    • @silvermica
      @silvermica 2 ปีที่แล้ว +1

      @@drpeyam Rad

  • @lunaticluna9071
    @lunaticluna9071 ปีที่แล้ว

    if anyone is interested, the equation for a neumann oval in cartesian coordinates is (x²+y²)²=a²(x²+y²)+4b²x²

  • @CornishMiner
    @CornishMiner 2 ปีที่แล้ว +1

    Beautiful

  • @mathevengers1131
    @mathevengers1131 2 ปีที่แล้ว +1

    I have a question. Is there any general equation for oval or egg shape. I tried to search a lot on google but they show general equation of ellipse? Even google confused between oval and ellipse 😅

    • @tanyuhur7055
      @tanyuhur7055 2 ปีที่แล้ว +1

      Not sure about egg shape but for an oval that is symmetrical along the x and y axis u use the equation of ellipse

    • @mathevengers1131
      @mathevengers1131 2 ปีที่แล้ว

      @@tanyuhur7055 the symmetric oval is an ellipse. It's like, as a circle is a special type of ellipse when major and minor are equal, a symmetric oval is same as an ellipse whose axis are symmetrical. But what about not a symmetrical oval. That would be like an egg shape, like small or squeezed on one side of ellipse.

    • @IoT_
      @IoT_ 2 ปีที่แล้ว

      @@mathevengers1131 I'll post the link. I hope it won't be removed

    • @mathevengers1131
      @mathevengers1131 2 ปีที่แล้ว +1

      @@IoT_ most probably it's removed

    • @IoT_
      @IoT_ 2 ปีที่แล้ว

      @@mathevengers1131 TH-cam deletes all of my comments

  • @moienbarkhori327
    @moienbarkhori327 2 ปีที่แล้ว

    it seems that the shape u presented does not math the mapping. it is a cardioid

  • @w.p.9509
    @w.p.9509 2 ปีที่แล้ว

    I'm just watching this because I find it very interesting how smart some people really are haha

  • @SuperYoonHo
    @SuperYoonHo 2 ปีที่แล้ว

    haha awesome! thanks a lot

  • @abdonecbishop
    @abdonecbishop 2 ปีที่แล้ว +2

    Hello again.....do not forget the Binomial theorem.....and sin and cos substitution for y and x in ( x + y)^n expansion ..........then because the function's is assumed a continuous differentiable for reducing and increasing powers expressed in the derivative and antiderivative representations......... captured to ...... n(x + y )^n-1 + 0 and (x + y)^n + z calculus (functional) transformation. The action of continuous differentiation terminates when the nth derivative of ( x + y)^n = 0 and (n-1)^th derivative of ( x + y)^n = const = Pn , given Pn is the n^th successor prime number P......and....?

    • @abdonecbishop
      @abdonecbishop 2 ปีที่แล้ว +1

      ?.... gosh.... almost forgot.....P is A Gaussian Prime ...and...GP = P mod(4) = 3 ....defines a set of grouped points intersecting the Cartesian plane at points calculated using Euler's amazing formula ..... one of many such number theoretic formulae....may one say you bring energy and humor to communicative mathematics