Three Geometric Series in an Equilateral Triangle (visual proof without words)

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  • Опубліковано 24 тра 2024
  • This is a short, animated visual proof demonstrating the sum of three infinite geometric series using dissection proofs in an equilateral triangle. In particular, we show how to find the sum of powers of 1/2, of powers of 1/3 and of powers of 1/7 in the equilateral triangle. Geometric series are important for many results in calculus, discrete mathematics, and combinatorics.
    If you like this video, consider subscribing to the channel or consider buying me a coffee: www.buymeacoffee.com/VisualPr.... Thanks!
    Also, check out my playlist on geometric sums/series: • Geometric Sums
    This animation is based on a proof by Stephan Berendonk (2020) from the November 2020 issue of The College Mathematics Journal, (doi.org/10.1080/07468342.2020... p. 385)
    #mathshorts​ #mathvideo​ #math​ #calculus #mtbos​ #manim​ #animation​ #theorem​ #pww​ #proofwithoutwords​ #visualproof​ #proof​ #iteachmath #geometricsums #series #infinitesums #infiniteseries #geometric #geometricseries #equilateraltriangle
    To learn more about animating with manim, check out:
    manim.community
    ______________________________
    Music in this video:
    Reaching The Sky (Long Version) by Alexander Nakarada (CreatorChords) | creatorchords.com
    Music promoted by www.free-stock-music.com
    Creative Commons / Attribution 4.0 International (CC BY 4.0)
    creativecommons.org/licenses/...

КОМЕНТАРІ • 68

  • @BadlyOrganisedGenius
    @BadlyOrganisedGenius Місяць тому +27

    The 1/7 construction is gorgeous

  • @dutchyoshi611
    @dutchyoshi611 Місяць тому +13

    I noticed something here: The denominator is always one more than the numerator, and so i thought that the infinite sum from one to infinity of x divided by (x+1)^y should always equal one. And sure enough, when i plugged the function into wolframalpha, it did say that it does indeed converge to one. These proofs are a beautiful way of showing the beauty of complex mathematical equations, like infinite sums as shown here

    • @deananderson7714
      @deananderson7714 Місяць тому

      Indeed if we use the formula
      sum = a/(1-r) for first term a and ratio r we get
      sum = (x/(x+1))/(1-1/(x+1)) multiply top and bottom by x+1
      sum = x/(x+1-1) = x/x = 1
      another observation we can make from the video is if we do the sum of first term 1/x with ratio 1/x we get 1/(x-1) as
      sum = (1/x)/(1-1/x) multiply top and bottom by x
      sum = 1/(x-1)

    • @eonasjohn
      @eonasjohn Місяць тому

      1 - 1/2^n

    • @megachonker4173
      @megachonker4173 16 днів тому

      Infinite sums are not complex.

  • @ruilopes6638
    @ruilopes6638 Місяць тому +17

    I looked at the last construction and wasn’t convinced that it should be a seventh. Tried to prove it myself easily. Couldn’t. Brute force it with analytic geometry.
    2 seconds later it rearranged itself and it was so obvious it had to be a seventh.
    Such a gorgeous construction

    • @douglaswolfen7820
      @douglaswolfen7820 Місяць тому

      I did something similar, but even after the rearrangement it wasn't completely obvious to me. Took some thinking, but I __think__ I could prove it rigourously now

    • @ruilopes6638
      @ruilopes6638 Місяць тому +1

      @@douglaswolfen7820 I could see that all the angles on the intersections were 60 degrees( the central triangle is clearly equilateral. The rest follow by alternating and opposing angles). After the rearranging all those new triangles have to be equilateral

  • @muse0622
    @muse0622 Місяць тому +3

    These fractals are the visualization of 0.nnnn(base n+1).

  • @Smartas599
    @Smartas599 Місяць тому +1

    Thanks! Keep up the good work

  • @user-cd9dd1mx4n
    @user-cd9dd1mx4n Місяць тому +1

    Amazing as usual!
    Actually very enjoyable ❤
    Keep uploading 👏👍

  • @adw1z
    @adw1z Місяць тому +3

    So beautiful as always, thank u for sharing!
    I have a video suggestion, on a very underrated fact I feel everyone should know: can u show that sin(54*) = phi/2, where phi is the golden ratio?

    • @MathVisualProofs
      @MathVisualProofs  Місяць тому +2

      I have it on the channel recently: ua-cam.com/video/Mi_Uo4eRWcE/v-deo.htmlsi=4e0Vhp8KNF0iOab6

  • @matematicasantiagofiore
    @matematicasantiagofiore Місяць тому +1

    Excellent!

  • @youoyouoyou
    @youoyouoyou Місяць тому +1

    Fun! You take an equilateral triangle and remove area such that you leave one or more smaller equilateral triangles. Then you repeat. Simple. Beautiful.

  • @bmx666bmx666
    @bmx666bmx666 Місяць тому +2

    Amazing visualization, I love it, thanks! 🔥🔥🔥

    • @MathVisualProofs
      @MathVisualProofs  Місяць тому

      Thanks!

    • @leif1075
      @leif1075 Місяць тому

      ​​@@MathVisualProofsit's very nice thanks for sharing but zi don't think k the triangle proof at 1:30 is very clear
      .wjat is 2/3 and how os the denominator being multiplied by a factor of 3..I'd be surprised of anyone actually understood that one..how can they right? I.think something is missing?

    • @MathVisualProofs
      @MathVisualProofs  Місяць тому

      @@leif1075 The first part cuts the triangle into three equal area pieces. Then only two are left shaded. In the next step, we divide the unshaded 1/3 into 3 equal area pieces and shade two of them. So we have just shaded 2/3 of the unshaded 1/3. That means we shaded 2/3^2. After that, we repeat on the remaining unshaded 1/3 of 1/3 and shade 2/3 of that, etc.

  • @alanthayer8797
    @alanthayer8797 Місяць тому +2

    Da VISUALS Visuals visuals = complete Individuals !

  • @cookiehead4759
    @cookiehead4759 Місяць тому +6

    Beautiful and smart way to make you love geometry and understand the link with algebra. Thank you for sharing

  • @user255
    @user255 Місяць тому +1

    Nice!

  • @tomjones6777
    @tomjones6777 Місяць тому +1

    Cool !

  • @anadiacostadeoliveira4
    @anadiacostadeoliveira4 Місяць тому +2

    Triangle fractals!!!

  • @ishtaraletheia9804
    @ishtaraletheia9804 Місяць тому +3

    Quite literally breathtaking! :O

  • @puzzleticky8427
    @puzzleticky8427 Місяць тому

    Chill math
    I like you cutchi

  • @astropeter31415
    @astropeter31415 12 днів тому +1

    The infinite sum of half reminds me of me making a spiral in a rectangle only using half, quarter, eighths, sixteenths,...

  • @KaliFissure
    @KaliFissure Місяць тому +1

    Corny but the classical and plane geometry are just perfect together

  • @vennstudios9885
    @vennstudios9885 Місяць тому

    wait so let me get this straight
    the sum of all n^-x where x is an integer
    is basically just (n-1)^-1 right? we already know that right
    so if we were to do something like
    (n-1)×SUM ALL(n^-x) is basically just 1
    or maybe even maybe if we make (n-1) be any number
    it can now be solved as Ω Where Ω is any number other than 0
    Ω/(n-1) where n is greater than 1

  • @user-kn6sw2jl2p
    @user-kn6sw2jl2p Місяць тому +1

    WoW

  • @mysyntax1311
    @mysyntax1311 Місяць тому

    could you post the manim code

  • @user_08410
    @user_08410 Місяць тому +2

    wow

  • @user-pq8qi6mn8n
    @user-pq8qi6mn8n Місяць тому

    did you use the manim library if so how did you learn it i want to learn it too

    • @MathVisualProofs
      @MathVisualProofs  Місяць тому

      Yes. This is in manim. If you know python, then I would just pick something you want to animate and start playing around. The documentation on the site will get you started and then you want to maybe check out a view tutorials online (something like Benjamin hackl, Brian amedee, theorem of Beethoven, or Varniex). Join the manim discord. I didn’t do these things - I just started playing around (over three years ago). Slowly you will pick things up.

    • @user-pq8qi6mn8n
      @user-pq8qi6mn8n 29 днів тому

      @@MathVisualProofs thanks! will do

  • @happystoat99
    @happystoat99 Місяць тому +1

    I don't get where the * 1/3 and *1/6 come from for 2/3 * 1/3 and 1/6^2?

    • @Kokice5
      @Kokice5 Місяць тому +4

      Because the smaller shapes are 1/3 and 1/6 of the size of tthe original.

    • @happystoat99
      @happystoat99 Місяць тому +2

      @@Kokice5 Ha yes, got it, thanks :)

  • @ESeth-xb5cu
    @ESeth-xb5cu 14 днів тому

    lim X -> inf x sig n=1 ((y-1)/(y^n)=1

  • @Bruh_80575
    @Bruh_80575 Місяць тому

    with that we can make a formula that every fraction that goes like 1/x^i equals 1/x-1

    • @duckyoutube6318
      @duckyoutube6318 Місяць тому

      What do you do when x=1? Or 3^0?

    • @Bruh_80575
      @Bruh_80575 Місяць тому +1

      @@duckyoutube6318 when x=1 we get that this is equal to 1/0, but is also equal to 1+1+1+1+..., therefore we could say that 1/0 is infinity

    • @Bruh_80575
      @Bruh_80575 Місяць тому +1

      But there are some other proofs that say that 1/0 can not be equal infinity so its a really complicated problem

    • @Bruh_80575
      @Bruh_80575 Місяць тому

      Maybe i’ll do a video solving this problem sometime soon

    • @duckyoutube6318
      @duckyoutube6318 Місяць тому +1

      @@Bruh_80575 ahh that makes sense. Ty for the reply

  • @stevehines7520
    @stevehines7520 Місяць тому

    "All" from Divine Be-ginning non-material.

  • @_.1_teja
    @_.1_teja Місяць тому

    Initially there was no infinity in the triangle...

    • @DriftinVr
      @DriftinVr Місяць тому +1

      There always has been, just not discovered or thought of

  • @Babychesssalmon
    @Babychesssalmon Місяць тому +1

    hi first

  • @abdo01386
    @abdo01386 Місяць тому +1

    Mathematician hate v proof and like more abstract math