Abstract Algebra | Lagrange's Theorem

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  • Опубликовано: 24 дек 2024
  • We prove some general results, culminating in a proof of Lagrange's Theorem.
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Комментарии • 14

  • @chasebrower7816
    @chasebrower7816 3 года назад +5

    Awesome! Got stuck on understanding Lagrange's Theorem in my class and this proof made it easy to understand.

  • @PSEmantic
    @PSEmantic 4 года назад +11

    This was perfect. Thanks. Can you sometime do like a video about Euler-Fermat's theorem proof and more Group theory.
    Keep it up!

    • @MichaelPennMath
      @MichaelPennMath  4 года назад +3

      Thanks! I have a number theory proof of Euler-Fermat's Theorem: ruclips.net/video/ijT3pmmal00/видео.html,
      and I plan to add a proof involving group theory soon.

  • @georgettebeulah4427
    @georgettebeulah4427 4 года назад +3

    This make so much sense and meaning and can relate what your saying and doing but which to learn more and see more video

  • @하정훈-j2j
    @하정훈-j2j 4 года назад +3

    Thank you very much for the video! I don't know if I can get an answer for my question, but here's my question:
    How can we say that the property that g itself is an element of coset of G (=g is an element of gH) implies that all union of gH is equal to the G?
    I understood that g is in fact an element of coset, and distinct cosets are disjoints, but I guess I just need one more line of explanation.
    Thank you

    • @Brien831
      @Brien831 4 года назад +4

      every g produces a corset of H. Not every corset is unique though so that when u have a total of n corsets some n-k are the same. So the disjunct union of the k unique corsets is the same as the union of the n corsets produced by G. since every corset contains g itself it is obvious that each g is contained in the union of all corsets.

    • @하정훈-j2j
      @하정훈-j2j 4 года назад

      @@Brien831 What a great explanation! Thanks

  • @abnereliberganzahernandez6337
    @abnereliberganzahernandez6337 Год назад

    in the sumation the indexes are up to k which is the number of cosets of h over g. before you demonstrated that two cosets have elements in common then they must be equal that is g1H=g2H.
    so what happens when for any reason there are repeated cosets. lagranges formula does not take into account that situation since the indices are up to k.
    I am a litle bit confused on that.
    cause as I see it the option that g1H=g2H for two diferent elements of g then this two sets are equal but their indexes are took into account eitherway

  • @karankk523
    @karankk523 4 года назад +4

    Your videos are good for group theory
    Please suggest me a book. For abstract algebra
    Thank you for your help.

    • @MichaelPennMath
      @MichaelPennMath  4 года назад +6

      I teach from this nice open-source book: abstract.ups.edu/. If you master everything in this book then Dummit and Foote is a good choice.

  • @liseg7494
    @liseg7494 4 года назад

    When you said, in the first lemma, g1h=g2h' we can't conclude with this ? We don't have g1H include to g2H thanks to that ? Thank you for your help.

  • @haoli9220
    @haoli9220 4 года назад +1

    Absolutely brilliant

  • @FrankBria
    @FrankBria 4 года назад +1

    Maybe it should say a complete *and minimal* list of left cosets?

    • @wargreymon2024
      @wargreymon2024 9 месяцев назад

      They are distincts, kind of redundant to say that