a nice product from Ramanujan -- featuring 3 important constants!

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  • เผยแพร่เมื่อ 4 ส.ค. 2023
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ความคิดเห็น • 74

  • @MichaelRothwell1
    @MichaelRothwell1 ปีที่แล้ว +28

    Piece of cake. All he did was add a variable x, take logs (to convert infinite product to infinite sum), differentiate, simplify, integrate again, use a bunch of substitutions and a series representation of sec, and a (familiar) integral representation of Catalan's constant. ;)

    • @idjles
      @idjles ปีที่แล้ว +16

      Yeah, and Ramanujan did that while you were making your coffee for breakfast.

    • @mohammedsenhaji
      @mohammedsenhaji ปีที่แล้ว +7

      And don't forget that you have to check the conditions for every use of limit, derivation, integration rules for series and integrals involved. If written rigourously it is at least 6 pages.

    • @giannipiccioni8411
      @giannipiccioni8411 ปีที่แล้ว +10

      ​@@mohammedsenhaji it would be only one line with a long enough page

    • @AncestorDad
      @AncestorDad 11 หลายเดือนก่อน +1

      New theory or formula may seems easy becos the inventor or discoverer tried many ways to simplify it as direct n simple as possible before presented it to you. But before that, nobody had the correct and simplest answer. They have tried many old, new, harder ways in order to find the correct one that is error proof. And this isn't really that easy or obvious, otherwise it would have been discovered way before he/she did, it is the unique creativity and ingenuity that lead each scientist made the contribution of their own. The sea of knowledge is so vast, no single person is smart or creative enough to discover n understand everything in the universe. We should respect and give the credit to all the scientist for all the discovery n invention they made, even if it is only 1 small equation, cos every equation count.

  • @humbledb4jesus
    @humbledb4jesus ปีที่แล้ว +49

    number theory is like getting a nasty sliver...you hate it, but you can't stop looking at it, picking at it, and finally getting knife to try and dig it out...

    • @Noam_.Menashe
      @Noam_.Menashe ปีที่แล้ว +4

      Where do you see number theory here?

    • @polyhistorphilomath
      @polyhistorphilomath ปีที่แล้ว +1

      @@Noam_.Menashe There's the product over factors of the form (1/(1-1/p))^c_k . That's probably a good indication number theory is involved.

    • @daburak2559
      @daburak2559 ปีที่แล้ว +2

      You watched the video and you thought of number theory?? How

    • @macicoinc9363
      @macicoinc9363 ปีที่แล้ว +3

      @@daburak2559euler’s prime product isn’t number theory? What is number theory to you if that isn’t apart of it?

    • @robertveith6383
      @robertveith6383 ปีที่แล้ว +1

      ​* a part "Apart" means "separated by a distance."

  • @endersteph
    @endersteph ปีที่แล้ว +51

    At 15:14 he forgot to change the inside of the integral to arctan z / z dz, but it doesn't change the result because the integral goes to 0 in the limit because of the bounds

    • @robertveith6383
      @robertveith6383 ปีที่แล้ว +5

      arctan(z)/z dz. Don't forget the grouping symbols.

    • @wolfmanjacksaid
      @wolfmanjacksaid ปีที่แล้ว +2

      Did he really do it by mistake? He wrote it again at 17:47

    • @martindedek2885
      @martindedek2885 ปีที่แล้ว +3

      I think he didn't want to substitute it to z, just the other two integrals. So I think that the mistake was that he changed the higher bound to tan(pi/4...), I think it should've been only pi/4... But still for X=1 it's 0 so the integral is irrelevant

  • @sanjogar
    @sanjogar ปีที่แล้ว +9

    Ramanujan was an alien 😂👽

  • @angeloluisrocattojunior3425
    @angeloluisrocattojunior3425 9 หลายเดือนก่อน +6

    I'm wondering what else Ramanujan would produce and discover if he had lived more than 32 years.

    • @user-ej7sr3ow8b
      @user-ej7sr3ow8b หลายเดือนก่อน

      He's probably just a messenger

  • @darkseid856
    @darkseid856 ปีที่แล้ว +84

    He predicted 4G technology . Truly ahead of his time .

    • @sahilsingh6048
      @sahilsingh6048 ปีที่แล้ว

      Tumnay profiel picture change karli kya

    • @om5621
      @om5621 ปีที่แล้ว +1

      ...what? he had nothing to do with even the internet whatsoever, is this some kind of joke

    • @Cccctyt
      @Cccctyt ปีที่แล้ว +1

      ​@@om5621also black holes

    • @aug3842
      @aug3842 ปีที่แล้ว +6

      @@om5621in the exponential there is the term 4G/π, and if u ignore the π in the denominator and treat G as just a letter rather than Catalans constant then it reads ‘4G’, which Ramanujan found well before the internet was created

    • @cristiandalessandro599
      @cristiandalessandro599 4 หลายเดือนก่อน

      ​@@om5621 yes, that's pretty much the best, most unpredictable joke. Quite hard to not understand it

  • @Trueman571
    @Trueman571 ปีที่แล้ว +9

    That's awesome - from "the man who knew infinity "

  • @franksaved3893
    @franksaved3893 ปีที่แล้ว +10

    Why is all the stuff about Ramanujan always fckin' crazy? 😅

  • @slavinojunepri7648
    @slavinojunepri7648 11 หลายเดือนก่อน +3

    What an awesome proof! Amazing to say the least.

  • @vasilisr7
    @vasilisr7 ปีที่แล้ว +1

    Thank you Michael

  • @ccg8803
    @ccg8803 ปีที่แล้ว +5

    Your videos are amazing, thank you! I cannot understand the views/quality ratio!

  • @user-zu5bv6sl5y
    @user-zu5bv6sl5y ปีที่แล้ว +2

    It was a very fascinating content

  • @gp-ht7ug
    @gp-ht7ug ปีที่แล้ว +2

    I miss the initial music of the videos.
    Very interesting video!

  • @curtiswfranks
    @curtiswfranks ปีที่แล้ว +3

    This one was pretty tricky.

  • @idjles
    @idjles ปีที่แล้ว +13

    I am sure the Ramanujan saw this identity immediately- he didn’t need 20 minutes of derivation to prove this.

    • @TheEternalVortex42
      @TheEternalVortex42 ปีที่แล้ว +3

      Ok well since you're "sure" I guess we know it for a fact

    •  11 หลายเดือนก่อน +2

      this is a very common misbelief

    • @damascus21
      @damascus21 9 หลายเดือนก่อน +1

      Ramanujan was a genius; he wasn't magic.

    • @idjles
      @idjles 9 หลายเดือนก่อน

      @@damascus21 he is so far beyond us, it may as well be magic.

    • @yuseifudo6075
      @yuseifudo6075 6 หลายเดือนก่อน

      ​Nah @@idjles

  • @minwithoutintroduction
    @minwithoutintroduction ปีที่แล้ว +4

    رحلة شاقة لكنها ممتعة

  • @jawadibrahim2367
    @jawadibrahim2367 11 หลายเดือนก่อน +6

    I was wondering for a solid minute why Newton's gravitational constant popped up in a mathematical result, only for it to be a different G in this case.
    I'm a little shook right now.

  • @Velociraptor103
    @Velociraptor103 ปีที่แล้ว +1

    Quite cool

  • @evid-rz3nu
    @evid-rz3nu ปีที่แล้ว +1

    nice video sir ji

  • @d.h.y
    @d.h.y 8 หลายเดือนก่อน +1

    Imagine you are a professor and all of a sudden a student brings up this identity in one random morning, while he brings up some incomprehensible pi formula (1/π =...) in the other day 😱😱

  • @missoss
    @missoss 9 หลายเดือนก่อน

    I love these random proof videos.

  • @natepolidoro4565
    @natepolidoro4565 ปีที่แล้ว +11

    Doesn't adding that n=0 term make the whole thing equal to zero as x->1?

    • @danmcalister2215
      @danmcalister2215 ปีที่แล้ว +1

      And then taking the log -> infinity?

    • @mohammedsenhaji
      @mohammedsenhaji ปีที่แล้ว +1

      Yeah but he doesn't take the limit until substracting the term again.

    • @curtiswfranks
      @curtiswfranks ปีที่แล้ว

      I think that this is the trickiest part.

  • @euler73
    @euler73 ปีที่แล้ว +3

    Is "Oh look, we've got...." then new "we can play the same game again..." ? ;-)

  • @reeeeeplease1178
    @reeeeeplease1178 10 หลายเดือนก่อน

    6:51 why don't we just view it (as he pointed out) as -pi/2 x sec(pi/2 x)? We should be able to integrate usec(u) with IBP, no?

  • @Maths_3.1415
    @Maths_3.1415 ปีที่แล้ว +5

    Interesting...

  • @Hexer1985
    @Hexer1985 ปีที่แล้ว +2

    Okay, great. So, the three important constants are e, G and \pi.

  • @adogonasidecar1262
    @adogonasidecar1262 11 หลายเดือนก่อน +1

    What happened at 14:21 when 4/Pi became Pi/4?

  • @emanuellandeholm5657
    @emanuellandeholm5657 ปีที่แล้ว +1

    I don't know about you guys, but my little ape brain was screaming difference of squares factorization as soon as I saw factors of the form [ 1 - ( 1 / (2n + 1) )^2 ] to the f(n). Is that something to explore?

  • @evid-rz3nu
    @evid-rz3nu ปีที่แล้ว +1

    love from india

  • @suzune8952
    @suzune8952 11 หลายเดือนก่อน

    Its pretty normal deriving this stuff , it isnt an alien thing...

  • @taranmellacheruvu2504
    @taranmellacheruvu2504 ปีที่แล้ว +1

    How can you justify that the limit means an equality? Can’t the point at x=1 be different from the limit as x goes to 1?

  • @erfanmohagheghian707
    @erfanmohagheghian707 ปีที่แล้ว +4

    I did the derivation of 1/cos(pi*x/2) on your behalf :) Thank you sir
    th-cam.com/video/vA0Q4-JgdNU/w-d-xo.html

  • @Packerfan130
    @Packerfan130 ปีที่แล้ว +2

    so many cheats, why bother doing the video at that point then?

    • @EphemeralEphah
      @EphemeralEphah ปีที่แล้ว +9

      Would you want the video to be well over an hour long? I assume proving the integral representation of G is equal to the series definition would take quite a while and could be it's own video, and I imagine deriving the series representation of sec((pi/2)x) is not so simple either.

    • @zlodevil426
      @zlodevil426 ปีที่แล้ว +7

      A lot of his videos reference other videos, most reference ones in the past, and this one just references videos in the future. What’s the significant difference?

    • @TheEternalVortex42
      @TheEternalVortex42 ปีที่แล้ว +4

      All math is built on earlier work. It's fairly arbitrary which results we would want proven and which are considered known.

    • @cameronbigley7483
      @cameronbigley7483 ปีที่แล้ว +1

      ​@@zlodevil426I don't mind referencing other videos, but I'd ptefer if an important step was already uploaded prior.

    • @samuelgoodman6067
      @samuelgoodman6067 11 หลายเดือนก่อน +1

      @@EphemeralEphah It's actually one line. Use the Taylor series for arctan.