An arithmetic-geometric limit

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  • Опубликовано: 18 ноя 2024

Комментарии • 34

  • @MathFromAlphaToOmega
    @MathFromAlphaToOmega Год назад +48

    As an interesting consequence, this shows that e^t ≥ t+1 from the AM-GM inequality, with equality if and only if t=0.

  • @complexquestion3601
    @complexquestion3601 Год назад +38

    There's a solution that's fairly simpler. The GM can be rewritten as (n!)^(t/n). Use Stirling's formula for n!, and because of the t/n exponent almost all factors have a limit of 1, and you're left with an asymptotic equivalent of (n/e)^t for the GM.
    Next, plug this equivalent into the GM/AM quotient, which is now (n^t / e^t )* (n/(sum of i^t from 1 to n)). Then divide both the numerator and the denominator by n^t, which transforms the AM term into (sum of (i/n)^t from 1 to n)/n, which in the limit is the definition of the Riemann integral of (x^t dx) from 0 to 1. All that's left is to compute the integral, which gives 1/(t+1), and plug that into the quotient, giving (t+1)/e^t.

  • @adiaphoros6842
    @adiaphoros6842 Год назад +20

    Geomethic Arithmedian.

  • @HagenvonEitzen
    @HagenvonEitzen Год назад +8

    11:04 Well, "approximating too small" only holds if the integrand is increasing, in other words, if t>0

    • @user-en5vj6vr2u
      @user-en5vj6vr2u Год назад

      Good point. You can also squeeze thm the GM and AM alone then you won’t have to worry about flipping inequalities

  • @cmilkau
    @cmilkau 11 месяцев назад

    Fun fact: the natural log of the geometric mean it's the arithmetic mean of the natural logs.

  • @ridefast0
    @ridefast0 Год назад +18

    Speaking of AM and GM, I enjoyed finding the 'hybrid' AGM in the formula for the exact period of a simple pendulum. Would that be worth a look, Michael?

    • @nirajmehta6424
      @nirajmehta6424 Год назад +1

      sounds very interesting!

    • @BilalAhmed-wo6fe
      @BilalAhmed-wo6fe 10 месяцев назад

      Sound interesting

    • @ridefast0
      @ridefast0 10 месяцев назад

      leapsecond.com/hsn2006/pendulum-period-agm.pdf

    • @peilingLeslieLiu
      @peilingLeslieLiu 5 месяцев назад

      indeed gauss AGM yield pi fastest :) and also arttan

  • @ianjlilly
    @ianjlilly Год назад +1

    John Cook has done some articles on these topics recently.

  • @blazeottozean469
    @blazeottozean469 Год назад

    Can we apply the limit of GM and AM separately (get some kind of infinity) then combine together to get the answer?
    Like: lim GM = lim n^t/e^t
    lim AM = lim n^t/(t+1)

  • @BongoFerno
    @BongoFerno Год назад +1

    I'm never sure if this is serious math, or trolling non mathematicians people.

  • @minwithoutintroduction
    @minwithoutintroduction Год назад +1

    22:24 رائع جدا كالعادة

  • @ruilopes6638
    @ruilopes6638 Год назад +4

    Shouldn’t our assumptions about t happen when we are looking for the inequalities on the AM. t been lesse than one there flips the inequalities the other way around.
    I believe what was calculated holds only for t>1

  • @zachbills8112
    @zachbills8112 Год назад +2

    I just used Stirling's Approximation up top and approximated the bottom sum by it's integral, which is valid asymptotically. This is simple enough to do in your head.

  • @iGeen7
    @iGeen7 Год назад +1

    But what about t

  • @faradayawerty
    @faradayawerty Год назад +1

    this is awesome

  • @gp-ht7ug
    @gp-ht7ug Год назад +1

    Nice video! ❤️

  • @nikhilprabhakar7116
    @nikhilprabhakar7116 Год назад +7

    Where is @goodplacetostop ???

  • @Alan-zf2tt
    @Alan-zf2tt Год назад +1

    I think I may take up knitting 🙂

    • @stefanalecu9532
      @stefanalecu9532 Год назад +1

      I fully encourage you in this endeavor

    • @Alan-zf2tt
      @Alan-zf2tt Год назад

      @@stefanalecu9532Thank you! I do not know whether to thank you or curse as there seems playful ambiguity on "this"
      I will take a finer interpretation and double up on "Thanks dood!" 🙂

  • @stevenmellemans7215
    @stevenmellemans7215 Год назад

    Why not the integral from 0 to n of x^t dt instead of adding the one?

  • @bndrcr82a08e349g
    @bndrcr82a08e349g Год назад

    Beautiful

  • @eugen9454
    @eugen9454 Год назад

    What was is used for? Because for a standalone publication is to easy, no?

    • @EinsteinsHair
      @EinsteinsHair Год назад +1

      It has been 30 years since I looked at Mathematics Magazine, but this is probably not too easy. The magazine is aimed at undergraduate teachers and students. As I remember they also included Problems to solve. Also Proofs Without Words showing simple geometric proofs. Not exactly a formal Journal.

  • @peilingLeslieLiu
    @peilingLeslieLiu 5 месяцев назад

    ❤interesting 😊

  • @juniorcyans2988
    @juniorcyans2988 Год назад

    Amazing🎉🎉🎉So fun❤❤❤