[a,b] is compact

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  • Опубликовано: 5 янв 2025

Комментарии • 26

  • @RalphDratman
    @RalphDratman 4 года назад +11

    That proof is more complicated than I expected. It gives me the feeling that compactness is deep.

    • @drpeyam
      @drpeyam  4 года назад +4

      Yeah, it actually shows how nice abstraction is! This proof for example is more direct, but more complicated

    • @wise_math
      @wise_math 3 года назад

      The video is published 1 day ago, how can the comment be 1 month ago??

    • @RalphDratman
      @RalphDratman 3 года назад

      @@wise_math The date is wrong, somehow. I remember this video from at least three months ago, probably more.

  • @NudelMaster
    @NudelMaster Год назад +1

    Beautifully done. Thank you for the extensive proof 👏

  • @Happy_Abe
    @Happy_Abe 3 года назад +3

    Beautiful proof, saw this in my class last semester!

  • @fatihucan3573
    @fatihucan3573 Год назад

    thank u for this brilliant proof Mr. Peyam :)

  • @raulsierra5315
    @raulsierra5315 3 года назад +1

    I don't even need to use this knowledge but I love your videos and these are quiet relaxing and helps me while I'm doing my stuff. Btw I really aprecciate your way of teach us, I'm an student of actuary, thx for help.

    • @drpeyam
      @drpeyam  3 года назад

      Thanks so much!!!

    • @pbj4184
      @pbj4184 3 года назад

      Hey a view is a view, money is green, amirite :P

  • @thomasmagnuson5039
    @thomasmagnuson5039 3 года назад +2

    I think you want to say C = {x\in [a,b] | [a,x] CAN be covered by finitely many elements in the open cover}.

  • @brunoamezcua3112
    @brunoamezcua3112 3 года назад

    cool video, great work!

  • @AhmadAhmad-qx6fp
    @AhmadAhmad-qx6fp 3 года назад +1

    Yeaaahh..! But is it tight though?
    * oh wait..!
    Wrong forum..
    Dang it!

  • @dgrandlapinblanc
    @dgrandlapinblanc 2 года назад

    Hard. Thank you very much.

  • @aneeshsrinivas9088
    @aneeshsrinivas9088 2 года назад

    Do general proofs of compactness from the definition look something like this?

  • @stefanomicheletti137
    @stefanomicheletti137 3 года назад

    I left a comment few days ago about a possible slightly different proof, but I can't see it anymore. Removed?

    • @drpeyam
      @drpeyam  3 года назад +1

      I’m not really sure, I don’t think I removed it

  • @martinb3000
    @martinb3000 4 года назад

    I never studied metric spaces as such but have enjoyed your series covering them (pun not intended!). Thank you.
    Since a set is compact only if *all* open covers of it has a finite covering subset I think the first sentence in the board should replace "an" with "any" so that it becomes: Suppose 𝑢 is *any* open cover of [a,b] ...
    Or even: Let 𝑢 be any open cover of [a,b] ...
    This to make it clear the proof handles all open covers of the interval.
    Or is such phrasing not needed even if being strict?

    • @drpeyam
      @drpeyam  4 года назад

      Doesn’t matter. Here by an it is implied that it’s an arbitrary sub cover.

  • @noahteague9850
    @noahteague9850 3 года назад +2

    What did we do to deserve two videos in one day? 😄

    • @drpeyam
      @drpeyam  3 года назад +2

      Just for being so awesome :)

    • @pbj4184
      @pbj4184 3 года назад

      @@drpeyam PR: 10000 👌

  • @vrowniediamond6202
    @vrowniediamond6202 3 года назад

    Sequential compactness seems easier

    • @vrowniediamond6202
      @vrowniediamond6202 3 года назад

      @Rick Does Math it wouldn't matter for metric spaces either ways. Eh

  • @lacasadeacero
    @lacasadeacero 3 года назад

    More Books! I mean More research!