A RIDICULOUSLY AWESOME INTEGRAL: int 0 to π/2 xsin(x)cos(x)ln(sin(x))ln(cos(x))

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  • Опубликовано: 2 ноя 2023
  • Merch (Advanced MathWear):
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Комментарии • 31

  • @venkatamarutiramtarigoppul2078
    @venkatamarutiramtarigoppul2078 Месяц назад

    After applying the kings property just multiply numerator & denominatior by 8 take sin^2 x = t sin2x dx = dt & cos^2 x =1-t. So the integral sorts out to pi/32 integral on 0 to 1 ln x ln (1-x )dx & just expand ln (1-x) obtain sum as sum of positive integers 1/n*1/(n+1)^2 which is a telescoping sum

  • @Daniel-yc2ur
    @Daniel-yc2ur 8 месяцев назад +4

    You make it look effortless haha

  • @nicogehren6566
    @nicogehren6566 8 месяцев назад +1

    beautiful solution. keep rocking on integrals.

  • @MrWael1970
    @MrWael1970 8 месяцев назад +1

    Very interesting solution. Smart and Simple solution. Thank you very much.

  • @trelosyiaellinika
    @trelosyiaellinika 3 месяца назад

    Indeed ridiculously awesome! The title is well-chosen! I have become an addict of your videos! You must take responsibility, there's no cure... 🤣 Jokes aside, thanks for your effort!

  • @jieyuenlee1758
    @jieyuenlee1758 4 месяца назад

    11:15 or plug specific values into the digamma function:
    f(z+1)
    =-A+Sum(k=[1,inf],(1/n-1/(n+1)
    where f is the digamma function;
    A is the euler masheroni constant

  • @nicolastorres147
    @nicolastorres147 8 месяцев назад +7

    Cool, loving your integral videos! Can you please make a video proving those gamma prime and digamma values on your shirts?

    • @maths_505
      @maths_505  8 месяцев назад +2

      instagram.com/p/Cuak4YaNRy9/?igshid=MzRlODBiNWFlZA==

    • @nicolastorres147
      @nicolastorres147 8 месяцев назад +1

      @@maths_505 Wow, you have a bunch of them proved on your IG! So cool, you just got a new follower! 🥳

  • @georgehenes3808
    @georgehenes3808 8 месяцев назад +3

    That is, indeed, ridiculously awesome. 👏

  • @michaelhoffman9172
    @michaelhoffman9172 8 месяцев назад +1

    The beta and gamma functions aren't really necessary. Starting with the integral from 0 to Pi/2 of sin(x)*cos(x)*ln(sin(x))*ln(cos(x)), make the
    substitution u = sin(x) to reduce it to 1/4 the integral from 0 to 1 of u*log(u)*log(1-u^2). Expand in powers of u and integrate term-by-term to
    get 1/4 the sum over n \ge 1 of 1/n(n+1)^2. The sum can be written as \sum_{n\ge1} 1/n(n+1) (which telescopes to 1) minus \sum_{n\ge1} 1/(n+1)
    (which is Pi^2/6 - 1). The conclusion then follows.

    • @uggupuggu
      @uggupuggu 6 месяцев назад

      what happens to the x at the front

    • @uggupuggu
      @uggupuggu 6 месяцев назад

      also what do you mean expand in powers of u

    • @Sparky1_1
      @Sparky1_1 5 месяцев назад

      @@uggupugguThe substitution is done after using the property of Definite integral”King Rule”. The x is removed by adding the I by both side then the LHS becomes 2I and we proceed further.

  • @sirnewton77
    @sirnewton77 8 месяцев назад +3

    Please solve putnam integrals 🙏

  • @Ghostwriter_zone
    @Ghostwriter_zone 8 месяцев назад +2

    Can u make some videos on summ of series using calculus?
    It's pretty interesting for me🎉😊

    • @maths_505
      @maths_505  8 месяцев назад +1

      There are a few in my playlist. I'll add more along the way.

  • @HisMajesty99
    @HisMajesty99 8 месяцев назад +3

    My good sir, I have a special request for you!
    There is an infinite series which many years ago I ran into but was not able to solve. I would be absolutely delighted if you could attempt it and post a solution. It is a series that converges to a very interesting value, and though I can find the answer online, I cannot find a solution or explanation for how to obtain it. It is as follows:
    ∞ (n!)²
    Sum ---
    n=1 (2n)!
    The result is: (9+2√3π)/27
    However, I was never able to figure out why 😢

    • @maths_505
      @maths_505  8 месяцев назад +1

      ruclips.net/video/xM4z0ncARlw/видео.html

    • @HisMajesty99
      @HisMajesty99 8 месяцев назад

      @@maths_505 you are a gdm LEGEND mate! The absolute mad lad already has a video on it….wow, surreal.
      Much appreciated man, cheers. 🙌
      And what a beautiful solution development :)

    • @maths_505
      @maths_505  8 месяцев назад +1

      @@HisMajesty99 tremendously appreciated your majesty

  • @TheArtOfBeingANerd
    @TheArtOfBeingANerd 7 месяцев назад

    Can you make a video, if you haven't already, expaining the little gamma Euler-whatever constant? I haven't been able to find it online. Thanks!

    • @maths_505
      @maths_505  7 месяцев назад +1

      In 2 or 3 videos

  • @GeoPeron
    @GeoPeron 3 дня назад

    I was like "um how tf did I get π/16-π³/192" but then I saw the answer and went "oh"

  • @nicolascamargo8339
    @nicolascamargo8339 8 месяцев назад

    Wow

  • @yoav613
    @yoav613 8 месяцев назад

    Nice! Can you pkease solve the integral (lnx)^2/sqrt(4-x^2) from 0 to 1 the result is 7pi^3/216.

    • @maths_505
      @maths_505  8 месяцев назад +1

      Sure

    • @yoav613
      @yoav613 8 месяцев назад

      @@maths_505 thanks😃

  • @juliotechnology
    @juliotechnology 8 месяцев назад

    Brasil!🎉

  • @giuseppemalaguti435
    @giuseppemalaguti435 8 месяцев назад

    π/16-π^3/192=π/16(1-π^2/12)...dovrei ricontrollare....

  • @juliotechnology
    @juliotechnology 8 месяцев назад

    🇧🇷💯