Proof: Euler's Formula for Plane Graphs | Graph Theory

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  • Опубликовано: 1 фев 2025

Комментарии • 39

  • @WrathofMath
    @WrathofMath  5 месяцев назад

    Support the production of this course by joining Wrath of Math as a Channel Member for exclusive and early videos, original music, and upcoming lecture notes for the graph theory series! Plus your comments will be highlighted for me so it is more likely I'll answer your questions!
    ruclips.net/channel/UCyEKvaxi8mt9FMc62MHcliwjoin
    Graph Theory course: ruclips.net/p/PLztBpqftvzxXBhbYxoaZJmnZF6AUQr1mH
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  • @ulissemini5492
    @ulissemini5492 4 года назад +9

    Great video! your enthusiasm makes a 15m proof feel like a 1 minute cat video

    • @WrathofMath
      @WrathofMath  4 года назад +2

      Thanks so much! That is as high praise as I can hope for, thanks for watching and let me know if you ever have any questions!

  • @555yashwant6
    @555yashwant6 Год назад +7

    Perfectly described in easy and simple language . All doubts cleared

  • @md8978
    @md8978 4 года назад +6

    Your videos help me out so much!! I have exams soon and watching your videos make the work so much easier to understand. Thank you!!

    • @WrathofMath
      @WrathofMath  4 года назад

      You're very welcome and thanks for watching! So glad the videos help, and good luck on your exams!

  • @mike_the_tutor1166
    @mike_the_tutor1166 4 года назад +3

    This is one of my favorite proofs and you've explained it beautifully! This is your best video yet! My only suggestion is to slow down your speech just a bit in future videos.

    • @WrathofMath
      @WrathofMath  4 года назад +1

      It is a wonderful proof! Thanks a lot and I appreciate the feedback! I always try to monitor the speed of my voice, but sometimes I no doubt lose track of it. I've got to take more time to breathe - which will naturally slow me down a bit!

  • @mariaritacorreia9340
    @mariaritacorreia9340 Год назад +3

    Thank you again.
    I didn't get the part on the minimum size condition. If it is minimum, how can we remove one edge?

  • @maxinimus
    @maxinimus Год назад +1

    awesome explanation and a very passionate one as well :)

  • @blade2.056
    @blade2.056 Месяц назад

    Beautifully explained better than my lecture notes which contains proof by induction( PS: We deep down all hate proof by induction xd )

  • @cobrametaliks490
    @cobrametaliks490 Год назад +3

    Hi 👋🏻
    Could you make a video about Kuratowski theorem?
    Thank you for your work 🙏🏻

  • @aispweelun
    @aispweelun 4 года назад +2

    Hi, thanks for this video. I have a question
    For the contradiction proof, are we assuming that n - m + r ≠ 2 is true for graph G with a minimum edges e? If that's the case, I don't understand how the G-e graph contradicts the n - m + r ≠ 2 because m-1 edges is already less than the minimum edges e so n - m + r ≠ 2 shouldn't apply to it

    • @ulissemini5492
      @ulissemini5492 4 года назад

      because after showing that n - m + r for G equals n - m + r for G-e it contradicts n - m + r ≠ 2
      basically, so long as there are cycles you can delete an edge from a cycle while leaving the formula unchanged, I like to think of applying this over and over until you get to a tree (no cycles) where we've already proven it!

    • @mrDustin0Channel
      @mrDustin0Channel 2 года назад +1

      let the vars of G-e be n', m' and r'
      so G-e holds n'-m'+r'=2
      now place the vars of G inside it
      n'-m'+r'=2=n-(m-1)+(r-1)
      and get n'-m'+r'=2=n-m+r
      so we did not change anything by deleting the edge regarding the formular
      we know the formular holds for G-e
      thus the formular holds for G aswell

  • @abiralkalbani8751
    @abiralkalbani8751 3 года назад

    Dr, Could you please prove this question?
    Let G and H be connected graphs different from K1 and K2.Show that both factors are paths or one is a path and the other a cycle.

  • @yeezyeez6326
    @yeezyeez6326 Год назад

    Hi why do we apply induction on m edges? Why not we apply induction on n vertices?

  • @benjaminlannis5050
    @benjaminlannis5050 9 месяцев назад

    Can you prove the Jordan Curve Theorem?

  • @jaeholee1092
    @jaeholee1092 3 года назад

    Why do we remove an edge? When you use induction, aren't you supposed to go from k edges to k+1 edges?

  • @PunmasterSTP
    @PunmasterSTP 8 месяцев назад

    Euler's Formula? More like "All these proofs are fantastic; thank ya'!" 👍

  • @StrifeHale
    @StrifeHale 4 года назад

    Perfect, thank you very much.

    • @WrathofMath
      @WrathofMath  4 года назад +1

      My pleasure, thanks for watching!

  • @andreeduenas
    @andreeduenas 4 года назад

    Thank you very much!

    • @WrathofMath
      @WrathofMath  4 года назад +1

      My pleasure, thanks for watching!

  • @Kevin-xs1ft
    @Kevin-xs1ft 2 года назад

    (Copied from J)
    Hi, thanks for this video. I have a question
    For the contradiction proof, are we assuming that n - m + r ≠ 2 is true for graph G with a minimum edge m? If that's the case, I don't understand how the G-e graph contradicts the n - m + r ≠ 2 because m-1 edges is already less than the minimum edges e so n - m + r ≠ 2 shouldn't apply to it

    • @rameezshafat
      @rameezshafat Год назад

      The task at hand involves proving a statement about a cycle graph. To do this, a minimum counterexample approach is being used, wherein the smallest possible instance that does not satisfy the statement is being considered. In order to prove the statement, it is necessary to show a contradiction, in this case we show it by deleting the edge. The goal of this contradiction is to demonstrate that the statement is, in fact, true for all cycle graphs, and that the counterexample is invalid.

  • @vishnum3690
    @vishnum3690 4 года назад

    Amazing!

    • @WrathofMath
      @WrathofMath  4 года назад

      Thanks for watching, Vishnu!

  • @sagnik.math7
    @sagnik.math7 3 года назад

    great !!!

    • @WrathofMath
      @WrathofMath  3 года назад +1

      Thank you! If you're looking for more graph theory check out my graph theory playlist! ruclips.net/p/PLztBpqftvzxXBhbYxoaZJmnZF6AUQr1mH

  • @gabrielpereiramendes3463
    @gabrielpereiramendes3463 4 года назад

    #Excelent!

  • @bedrichmazourek3289
    @bedrichmazourek3289 4 года назад

    I love you

  • @bowlineobama
    @bowlineobama Год назад

    I wish you would have used , V, E, and F labels instead of n, m and r.