This integral is actually one of your favorite constants

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  • Опубликовано: 20 окт 2024

Комментарии • 79

  • @maths_505
    @maths_505  6 месяцев назад +6

    If you like the videos and would like to support the channel:
    www.patreon.com/Maths505
    You can follow me on Instagram for write ups that come in handy for my videos and DM me in case you need math help:
    instagram.com/maths.505?igshid=MzRlODBiNWFlZA==
    My LinkedIn:
    www.linkedin.com/in/kamaal-mirza-86b380252

  • @emma5068
    @emma5068 6 месяцев назад +34

    I am a lady and I watch this channel. Happy to get the mention! All three and a half of us had better have commented.

    • @maths_505
      @maths_505  6 месяцев назад +6

      2 and a half of you have commented so far 😂

    • @jennisaurus715
      @jennisaurus715 Месяц назад +1

      I love watching these fun integrals while getting cozy before bed :)

  • @keyaanmatin4804
    @keyaanmatin4804 6 месяцев назад +47

    LOOOOL well done for avoiding the gamma function today. must have been real tough.😅

  • @0oAstro
    @0oAstro 6 месяцев назад +126

    Alright gentlemen and three and a half ladies,

    •  6 месяцев назад +10

      Missed opportunity though: no irrational number of ladies ...

    • @boredd9410
      @boredd9410 6 месяцев назад +3

      What next? A pi number of enbies?

    • @ribozyme2899
      @ribozyme2899 6 месяцев назад +6

      ​@@boredd9410 I'm the 0.1416 enby lol

    • @daliasprints9798
      @daliasprints9798 Месяц назад

      Jokes aside, RUclips has no information about gender. The gender breakdown of viewership is based on a made-up gender it assigned based on stereotypes of what kind of videos folks watch by gender. Classic GIGO.

  • @satyam-isical
    @satyam-isical 6 месяцев назад +6

    That switching between integral and summation operators is as beautiful as that u=(1-x)/(1+x) substitution

    • @Harmonicaoscillator
      @Harmonicaoscillator 6 месяцев назад +1

      It’s just due to uniform convergence of a function on the open interval of its power series expansion

  • @aravindakannank.s.
    @aravindakannank.s. 6 месяцев назад +12

    sorry mate a lil busy last two to three days so i missed out some videos i will quickly watch those tomorrow
    when u tried not to let intrinsive tought by not using gamma function i can't stop laughing because of the battle ur mind and heart
    finally u saved it for later video idea😂

  • @CM63_France
    @CM63_France 6 месяцев назад +4

    Hi,
    "ok, cool" : 0:16 , 2:27 ,
    "terribly sorry about that" : 1:36 , 2:23 .

  • @renerpho
    @renerpho 6 месяцев назад +7

    It was nice to see you go through gamma withdrawal, and make it to the other side intact.
    What was even nicer is how it appears to have sparked a video idea?!

    • @maths_505
      @maths_505  6 месяцев назад +2

      It was one of the darkest moments of my life but I'm grateful for the lessons learned.

  • @boltez6507
    @boltez6507 6 месяцев назад +3

    This can be also done by taking
    ln²1-x/1+x as t,doing some subsitutions,
    then integrating by parts and applying gamma function (at least i think so).

  • @pluieuwu
    @pluieuwu 6 месяцев назад +11

    glad to be one of the 7/2 ladies here 😂

  • @mikeoffthebox
    @mikeoffthebox 6 месяцев назад +1

    Rearranging to ux + x + u = 1, you can see it's symmetrical, so goes the same both ways.

    • @satyam-isical
      @satyam-isical 6 месяцев назад

      Nice observation
      This would be really useful in long expressions like higher degree polynomials...

  • @johnmich3459
    @johnmich3459 6 месяцев назад +1

    Hi, thanks for the fantastic video, just curious what software are you using for handwriting.

  • @yoav613
    @yoav613 6 месяцев назад +5

    Nice! My favorite sub u=(1-x)/(1+x)😊

  • @wqltr1822
    @wqltr1822 6 месяцев назад +1

    I think the integral could also be written as a multiple of the integral of (artanhx)^3, which is pretty cool

  • @nizogos
    @nizogos 6 месяцев назад +2

    By looking at the end result being (3^2)*ζ(3), I wonder if the result is always of the form n^2 *ζ(n) ( or n^(n-1) * ζ(n) ) ,where n is the logarithm power in the starting integral.

    • @sergiokorochinsky49
      @sergiokorochinsky49 6 месяцев назад +2

      Looking at 10:07... How about this?
      n! (2-2^(2-n)) Zeta(n)

  • @renerpho
    @renerpho 6 месяцев назад

    Challenge completed 🙂 Thank you!

  • @jhonnyrock
    @jhonnyrock 6 месяцев назад +1

    Hello, there's this crazy integral and its answer that's just stated on Wiki without the derivation, and I was wondering if you'd be up to the challenge of solving it!

    • @maths_505
      @maths_505  6 месяцев назад

      DM me the integral on Instagram.

  • @aymanalgeria7302
    @aymanalgeria7302 6 месяцев назад

    Pure nostalgie ❤

  • @SnowWolfie11
    @SnowWolfie11 6 месяцев назад +1

    Why is it not valid to simply integrate by parts where u = ln( (1-x) / (1+x) )^3 and dv = dx? After some basic simplification, when you plug in the bounds you get two ln( 0 )'s which is undefined. Also when I plug it into a not super complex calculator it also says the integral is undefined but can be approximated as the result in the video.

    • @maths_505
      @maths_505  6 месяцев назад +2

      That's cuz I haven't told the super complex calculator how to solve it yet😎😎

  • @MrWael1970
    @MrWael1970 6 месяцев назад

    When making geometric series -1/(1+u)^2, it should be appropriate to add 1 to the power of negative 1 in right side. So, it will be (-1)^(k). Anyhow, thank you for this interesting integral and innovative solution.

    • @mjpledger
      @mjpledger 6 месяцев назад

      He did do that but he decreased by 1 in the exponent rather than increase by 1, going from (-1)^k to (-1)^(k-1) to include the extra -1.

    • @MrWael1970
      @MrWael1970 6 месяцев назад

      @@mjpledger (-1)^(k-1) this is due to index of the summation to start with 1 instead of 0, but this is not the issue. Anyway Thanks.

    • @mjpledger
      @mjpledger 6 месяцев назад +1

      @@MrWael1970 No. The 0th term is 0 that's why he can disregard it and start at k=1. If he was re-indexing in k then both (-1)^k and u^(k-1) would have been affected but only (-1)^k was - to soak up the floating negative sign.

  • @merouan3922
    @merouan3922 6 месяцев назад

    Thanks can you publish about PDE problems

  • @brickie9816
    @brickie9816 Месяц назад

    i feel dumb cuz idk how you would continue after invoking the gamma function. gotta watch more maths 505 videos!

  • @Unidentifying
    @Unidentifying 6 месяцев назад +1

    request for some nonlinear PDEs

  • @slowf2l263
    @slowf2l263 6 месяцев назад

    how would you do it with gamma function tho

  • @tsa_gamer007
    @tsa_gamer007 6 месяцев назад +3

    Sir (math 505) could you please tell me the name of the constant which somewhat related to gamma^2(1/4)
    I believe you denote it with omega symbol

    • @Listenpure
      @Listenpure 6 месяцев назад

      Yes even I tried to find it out but he used to say it so fast I never knew what he said

    • @Listenpure
      @Listenpure 6 месяцев назад

      I also want to know the name of that constant which is denoted by L which once he told to a result of a summation

    • @ambiguousheadline8263
      @ambiguousheadline8263 6 месяцев назад +4

      I believe you mean the lemniscate constant, denoted with an omega and bar on top

    • @bennetdiesperger4080
      @bennetdiesperger4080 6 месяцев назад +2

      I think you are refering to the Lemniscate constant which is denoted by a ϖ (\varpi)

    • @4wdsquirrel48
      @4wdsquirrel48 6 месяцев назад +4

      I think it's the lemniscate constant, it's something like gamma^2(1/4) / 2sqrt(2pi)

  • @shivamdahake452
    @shivamdahake452 6 месяцев назад

    I have a feeling you know the half lady from the 3 and a half you mention.
    You could have used 3 and a quarter or 3 and three fourths, or really any fractional value lesser than 1. The very fact that you know its precisely 1/2 is a bit sus.
    Also nice integral.

    • @maths_505
      @maths_505  6 месяцев назад

      😂😂😂😂

  • @KarlSnyder-jh9ic
    @KarlSnyder-jh9ic 6 месяцев назад

    A virtuoso performance, eh? I am humbled. Which is good -- that's exactly where I should be. Maybe I'll revisit this in a year or two. Or three.

  • @sandyjr5225
    @sandyjr5225 6 месяцев назад +1

    Why do you say 3.5 ladies in the beginning? I'm really curious..

    • @shebo96
      @shebo96 6 месяцев назад +1

      it's a joke because most followers of this channel are guys

    • @rafiihsanalfathin9479
      @rafiihsanalfathin9479 6 месяцев назад +1

      Probably 3.5%

    • @maths_505
      @maths_505  6 месяцев назад

      Yeah it's just a joke😂

    • @abdulllllahhh
      @abdulllllahhh 6 месяцев назад

      @@maths_505my math ig page had a 60-40 gender split, which either means women are actually interested in integrals, or that there are guys lying about their gender… I think we both know which is really true

    • @Unidentifying
      @Unidentifying 6 месяцев назад

      shoutout to the 1/2 females out there, they exist

  • @thomasblackwell9507
    @thomasblackwell9507 6 месяцев назад +1

    Thanks for avoiding the Gamma and Beta functions. There use to me seems like cheating.

  • @JosBergervoet
    @JosBergervoet 6 месяцев назад +1

    His name was Roger Apéry, not Avery!

  • @surajbhatt4713
    @surajbhatt4713 6 месяцев назад

    Challenge completed ❤

  • @calculus8399
    @calculus8399 6 месяцев назад

    Nice

  • @Jalina69
    @Jalina69 6 месяцев назад +1

    I was never taught about the gamma function in uni. feeling so robbed.

    • @maths_505
      @maths_505  6 месяцев назад +1

      Pretty much every other video here makes use of the gamma function so you've come to the right place.

  • @BuleriaChk
    @BuleriaChk 6 месяцев назад

    For x imaginary (ix) and x < 1 the integrand suggests the relation psi*/psi which might have a relation to quantum mechanics and relativity (which fail because |sigma1|+|sigma2| is not a group in SU(2) because of the existence operator +. I have provided links to a number of documents relating to the vector-free foundation of mathematical physics at the physicsdiscussionforum organization for which this perspective might be relevent. Drop in and give me a call... :)

  • @bennokrickl8135
    @bennokrickl8135 6 месяцев назад +2

    I really like the video style and pace of the video, but say "oook, cool" one more time and I might break something 😅

    • @maths_505
      @maths_505  6 месяцев назад +4

      You'll get used to it eventually 😂

  • @sarahakkak408
    @sarahakkak408 6 месяцев назад

    Nice video

  • @dalibormaksimovic6399
    @dalibormaksimovic6399 6 месяцев назад

    Aperony constant

  • @edmundwoolliams1240
    @edmundwoolliams1240 6 месяцев назад

    Never would have guessed that initial substitution! Seems too obvious 😂

  • @anestismoutafidis4575
    @anestismoutafidis4575 6 месяцев назад

    ∫ 0->1 ln^3(0)•dx -[ln^3(1)•dx]
    ∫ [0] 0->1->0 [ 0]

  • @felipealonsoobandolopez9957
    @felipealonsoobandolopez9957 6 месяцев назад +2

    incredibleeeeee kjakjkj

  • @holyshit922
    @holyshit922 6 месяцев назад

    My way is following
    Substitution y = (1-x)/(1+x)
    We will get integral
    2\int\limits\_{0}^{1}\frac{ln\left(y
    ight)}{\left(y+1
    ight)^2}dy
    Now integrate by parts with clever choice of integration constant
    \int\limits\_{0}^{1}\frac{\ln^3\left(y
    ight)}{\left(y+1
    ight)^2}dy
    u = \ln^3\left(y
    ight) , du = \frac{3}{y}\cdot\ln^2\left(y
    ight)dy
    dv = \frac{1}{\left(y+1
    ight)^2}dy , v = (-\frac{1}{y+1}+A)
    0 - \lim_{x\to 0}\left((-\frac{1}{y+1}+A)\ln^3\left(y
    ight)
    ight)-3\int\limits_{0}^{1}(-\frac{1}{y+1}+A)\frac{\ln^2\left(y
    ight)}{y}dy
    Now if we choose A=1 we can evaluate limit and remaining integral will simplify
    We will get -6\int\limits_{0}^{1}\frac{\ln^2\left(y
    ight)}{1+y}dy
    Now I would use series expansion and then integration by parts

  • @DD-ce4nd
    @DD-ce4nd 6 месяцев назад

    Ooooookaay cool :-)

  • @agrimmittal
    @agrimmittal 6 месяцев назад +1

    three and a half ladies lol

  • @garvittiwari6266
    @garvittiwari6266 6 месяцев назад

    I guess it should be gentleman and imaginary ladies

  • @fahadibrar379
    @fahadibrar379 6 месяцев назад +1

    First'