ONE OF THE COOLEST INTEGRALS EVER!! int (0,1) ln(x)/sqrt(x(1-x^2))

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  • เผยแพร่เมื่อ 24 ธ.ค. 2024

ความคิดเห็น • 60

  • @renerpho
    @renerpho 8 หลายเดือนก่อน +1

    Have you done the integral of ln(gamma(x)) dx, with limits 0 and 1/2? It's a fun integral, and if you have never presented the Glaisher-Kinkelin constant on your channel, here's a perfect opportunity. There are quite a few very funky integrals and products involving that constant.

  • @joelchristophr3741
    @joelchristophr3741 9 หลายเดือนก่อน +14

    I like that when you say "ooookaayy cooll! " 😂😂

    • @CM63_France
      @CM63_France 9 หลายเดือนก่อน

      I think next time I'll count them, together with the "terribly sorry about that" , promised 😉

  • @ingenuity23-yg4ev
    @ingenuity23-yg4ev 9 หลายเดือนก่อน +2

    this is not just amazing it is "Kamaal"! love your videos!

  • @anaymulay7285
    @anaymulay7285 9 หลายเดือนก่อน +5

    Just waited for your video till late night
    Thanks for improving our math interest

    • @aravindakannank.s.
      @aravindakannank.s. 9 หลายเดือนก่อน +1

      bro i tried to be awake but slept😂

  • @MrWael1970
    @MrWael1970 7 หลายเดือนก่อน

    Very smart solution. Thanks.

  • @Tosi31415
    @Tosi31415 9 หลายเดือนก่อน +15

    do you know where i could find a table of all the gamma, digamma ,etc functions and all their relations with eachother?

    • @maths_505
      @maths_505  9 หลายเดือนก่อน +6

      Just follow me on Instagram you'll find lots of cool stuff I use in my videos there 😂

    • @angus8544
      @angus8544 9 หลายเดือนก่อน

      you could try the NIST handbook of mathematical functions

    • @ganonhorf8632
      @ganonhorf8632 9 หลายเดือนก่อน +1

      en.wikipedia.org/wiki/List_of_mathematical_functions?wprov=sfti1#Piecewise_special_functions
      Wikipedia page listing pretty much all of the special functions you’ll ever encounter. I couldn’t find a table showing how they’re related so you’re gonna have to look at each article individually

  • @Hobbitangle
    @Hobbitangle 9 หลายเดือนก่อน

    Before calculation the derivative of the ratio of two gamma functions it is convenient to make logarithm and then to differentiate, i.e.
    (log(Г(u)/Г(v)))'= (log(Г(u)))' - (log(Г(v)))'=
    psi(u)•u'- psi(v)•v'
    Because psi(x)=(log(Г(х)))'=Г'(х)/Г(х) by definition

  • @absurdengineering
    @absurdengineering 9 หลายเดือนก่อน

    Thank you for this one! It’s a really elegant one.

  • @MK_Search
    @MK_Search 9 หลายเดือนก่อน +4

    Around 6:10 when you take the derivative with respect to s, wouldn’t you get an extra factor of ½ from the chain rule with (s+1)/2 and (s+2)/2 inside the gammas?

    • @MK_Search
      @MK_Search 9 หลายเดือนก่อน +1

      Ah it’s fixed around 13:40 when you say the target integral was half of this I’(-1/2). It didn’t seem to be originally defined that way, but it gives the necessary extra factor of ½ to make the final result correct.

    • @maths_505
      @maths_505  9 หลายเดือนก่อน +10

      @@MK_Search classic case of two mistakes cancelling out 🤣🤣

  • @mikeoffthebox
    @mikeoffthebox 9 หลายเดือนก่อน +3

    That's a nice one.

  • @rayquazabtc9131
    @rayquazabtc9131 9 หลายเดือนก่อน +1

    Please make a video on the constant which you used at the end of video

  • @dawhat8561
    @dawhat8561 9 หลายเดือนก่อน +1

    Could you check if at 13:45 it’s actually 1/2 I can’t seem to understand where that 1/2 is coming from?

    • @dawhat8561
      @dawhat8561 9 หลายเดือนก่อน

      Very cool integral also

  • @saraandsammyb.9599
    @saraandsammyb.9599 9 หลายเดือนก่อน +3

    Where do you find all of these constants and their equivalent forms? Is there like a table of them?

    • @maths_505
      @maths_505  9 หลายเดือนก่อน +5

      The lemniscate constant was pointed out by a viewer and that's how I found out about it.

    • @edmundwoolliams1240
      @edmundwoolliams1240 9 หลายเดือนก่อน

      ​@@maths_505 The leminiscate biscuit

  • @twins10925
    @twins10925 9 หลายเดือนก่อน

    Why (***)/4√2 (***) in the minute 14:05 ...????

  • @edmundwoolliams1240
    @edmundwoolliams1240 9 หลายเดือนก่อน

    Is there a way to do this without the intermediate digamma steps? E.g some clever subs and trickery?

    • @maths_505
      @maths_505  9 หลายเดือนก่อน +1

      Not that I know of. But the final closed form in terms of the gamma function implies that the digamma function is pretty much unavoidable.

  • @skyethebi
    @skyethebi 7 หลายเดือนก่อน

    Can you do a video proving the relationship between the beta and gamma functions?

    • @maths_505
      @maths_505  7 หลายเดือนก่อน

      That's actually pretty trivial so I'll do a write up on my Instagram

    • @skyethebi
      @skyethebi 7 หลายเดือนก่อน

      @@maths_505 I don’t have instagram lol

    • @maths_505
      @maths_505  7 หลายเดือนก่อน

      @@skyethebi time to make one 😂

    • @skyethebi
      @skyethebi 7 หลายเดือนก่อน

      @@maths_505 honestly I’d love to see a video about the beta function in general and you can prove all the equivalent integral definitions of the beta function as well as if there are series or product representations and also the relationship with the gamma function

    • @skyethebi
      @skyethebi 7 หลายเดือนก่อน

      Considering how much you use the beta function I think it would be a good addition the same way you have videos proving properties of the gamma function

  • @lukesaul2919
    @lukesaul2919 9 หลายเดือนก่อน

    This integral should be decorated with hanging ribbons

  • @sadi_supercell2132
    @sadi_supercell2132 8 หลายเดือนก่อน

    No chain rule when differentiating gamma function? Derivative of gamma(2x) for example , its not gamma(2x) times derivative of 2x which is 2? Edit: nevermind i saw a correction in comments

  • @bobbybannerjee5156
    @bobbybannerjee5156 9 หลายเดือนก่อน

    Do you think this can be done without the use of the beta function?

    • @maths_505
      @maths_505  9 หลายเดือนก่อน

      The final result includes the gamma function so fortunately no.

    • @bobbybannerjee5156
      @bobbybannerjee5156 9 หลายเดือนก่อน

      @@maths_505 Thank you.
      Can you tell us the writing app/software that you use to write ✍️ electronically on your computer 🖥️ screen?

    • @maths_505
      @maths_505  9 หลายเดือนก่อน

      @@bobbybannerjee5156 I write on my tablet using an s pen and Samsung notes

  • @gabrielmartin2715
    @gabrielmartin2715 9 หลายเดือนก่อน

    Which constant is that ω? Some article about? Thankk you!!

    • @maths_505
      @maths_505  9 หลายเดือนก่อน +1

      Wikipedia should suffice. Search lemniscate constant.

  • @edmundwoolliams1240
    @edmundwoolliams1240 9 หลายเดือนก่อน

    It's asking for a trigonometric substitution, but the log on top ruins it!!

    • @maths_505
      @maths_505  9 หลายเดือนก่อน +1

      My dear friend....the logarithm yearns for trigonometric arguments.

  • @giuseppemalaguti435
    @giuseppemalaguti435 9 หลายเดือนก่อน

    My idea.. 1)x÷sint,perveliminare la radice al denominatore.. 2)feyman I(a) ={Sint} ^a.. con I=I'(-1/2)..3).noto che I(a) la posso esprimere in beta function..ok I=-√(π/2)(Γ(1/4))^2/4

  • @manstuckinabox3679
    @manstuckinabox3679 9 หลายเดือนก่อน

    I would use a combination of feynmann and contour integration according to my old friend gamelin taught me... I miss you gamelin... "Analyse par Jean Marie Monnier" got nothing on you :(.

  • @vlix123
    @vlix123 9 หลายเดือนก่อน

    For some reason I keep getting I(s)=1/2*B(s/2+1/4,1/2) and I dont see my mistake...

  • @tomasstride9590
    @tomasstride9590 9 หลายเดือนก่อน +2

    Viewing your videos I am very much left with the impression that you are someone who is very much steeped in the theory of special functions. I studied mathematic over 50 years ago ( mathematical physics to be exact) and naturally we covered all the special functions that come up so often in your solutions. But I can not say I have any of them in the forefront of my thinking. I am ok on the basic functions but can not see Gamma of Beta functions hiding inside integrals the way you can. I wonder if perhaps you are someone who managed to absorb the first half of Whittaker and Watson’s Modern Analysis. Its call Modern Analysis but must be getting on for being ninety years old, but still modern in my opinion.

    • @maths_505
      @maths_505  9 หลายเดือนก่อน +1

      I actually studied special functions in detail in the course of solving integrals. It's something I'm quite passionate about which is why I'm always on the hunt for opportunities to invoke them. I'll add Modern Analysis to my (growing) list of books to read.

    • @tomasstride9590
      @tomasstride9590 9 หลายเดือนก่อน +2

      @@maths_505 There are a great many topics I hoped to master but never in the end got round to studying. I guess in the end I was just too lazy. One of these things was the Wiener Hopf method for singular integral equations. I found it all rather difficult. Now if by some chance you could give me the understanding I lack in a twenty minute video then I would end my days ( I am well into my seventies) more satisfied that would be the case otherwise.

    • @maths_505
      @maths_505  9 หลายเดือนก่อน

      @@tomasstride9590 may Allah bless you with more years to come and yes I'll gladly take up that task my friend.

    • @tomasstride9590
      @tomasstride9590 9 หลายเดือนก่อน +1

      @@maths_505 This is a tall order so please don’t feel yourself under any pressure on my behalf. There is a classical book by Muskhelishvilli ( he has other book). In the seventies I borrowed the book from the library, but I never made it passed the first chapter. So it all went on the rather long list of things I failed to achieve.

    • @maths_505
      @maths_505  9 หลายเดือนก่อน

      @@tomasstride9590 thank you my friend. I've just started grad school and that's been taking quite a bit of my time but I will definitely try to squeeze some time out for such content.

  • @manjoker
    @manjoker 9 หลายเดือนก่อน

    ooookkaayyy coooll 😂

    • @maths_505
      @maths_505  9 หลายเดือนก่อน

      There's merch on that now 😂

  • @praneethmahantesh3252
    @praneethmahantesh3252 9 หลายเดือนก่อน +1

    Can you include JEE Advance questions pls 🥺

    • @maths_505
      @maths_505  9 หลายเดือนก่อน

      Could you email me some good ones? I'd love to help out.

    • @praneethmahantesh3252
      @praneethmahantesh3252 9 หลายเดือนก่อน

      @@maths_505 I got sir.

    • @mridulacharya8250
      @mridulacharya8250 9 หลายเดือนก่อน

      ​@@maths_505 search "jee simplified subject" U will get very good questions (in Hindi but don't listen to soln just see the soln instead ...or u can just search "mathsmerizing integrals questions".. English videos...and it has previous year questions of jee advanced as well

  • @arunknown2177
    @arunknown2177 9 หลายเดือนก่อน

    early!