This is SERIESLY NUTS! Deriving the Sum of Reciprocals of the Odd Numbers Squared using INTEGRALS!

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  • Опубликовано: 29 июн 2019
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    Let us calculate the infinite sum over the reciprocals of all the odd numbers squared today! It's going to evaluate to pi^2/8 and connects the riemann zeta function of two, namely the Basel Problem pi^2/6 and the Dirichlet Eta Function of 2, namely pi^2/12!
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Комментарии • 134

  • @helloitsme7553
    @helloitsme7553 5 лет назад +88

    Haters will say: you can just 3/4 of the sum of reciprocal squares

    • @silasrodrigues1446
      @silasrodrigues1446 5 лет назад +5

      I'm not a hater but I got that as the solution, then came Papa and gave a whole new way to find the same answer. That's one of the reasons I Love this boi!

    • @helloitsme7553
      @helloitsme7553 5 лет назад +1

      @@silasrodrigues1446 yeah it was a joke of mine haha

    • @MA-bm9jz
      @MA-bm9jz 5 лет назад +1

      Or just compare this one with 1/k^2 and they have the same nature

  • @ChrisChoi123
    @ChrisChoi123 5 лет назад +58

    man, that sexy pronunciation of integral always gets me

  • @noway2831
    @noway2831 4 года назад +10

    Engineers: Integrals are a kind of sum.
    Mathematicians: Sums are a kind of integral.

  • @blancosal
    @blancosal 5 лет назад +24

    Goal: being straight
    Obstacle: *I N T E GÆR A L*

  • @MrMelkorbaggins
    @MrMelkorbaggins 5 лет назад +7

    "let's Fubini this shit" applies to everything everywhere everytime

  • @eliyasne9695
    @eliyasne9695 5 лет назад +23

    I did it by adding and subtracting one fourth of zeta(2).

  • @frozenmoon998
    @frozenmoon998 5 лет назад +7

    When you have theorems and proofs which rely on Riemann's hypothesis.. You know that papa must prove it one day!

  • @ashimkadariya2698
    @ashimkadariya2698 5 лет назад +20

    I turn off ad block for this channel

  • @orangutan7934
    @orangutan7934 5 лет назад +16

    This was so ReciproCOOL.

    • @timothymoore2197
      @timothymoore2197 5 лет назад +1

      yo i'm definitely using this for my students lol

  • @atrumluminarium
    @atrumluminarium 5 лет назад +12

    I believe there's a way to evaluate this by using Parseval's identity if you want to cover more ways to evaluate this

  • @tatjanagobold2810
    @tatjanagobold2810 5 лет назад +3

    Normal mathematicians: "In this case we can switch the order of integration."
    Flammy: "Let's Fubini this shit!" :D

  • @yxlxfxf
    @yxlxfxf 5 лет назад +30

    *uses zeta(2) to solve this*
    wait that's illegal

    • @dannygjk
      @dannygjk 5 лет назад +2

      That's like using a 44 magnum to defeat a child proof bottle.

  • @TheNiTeMaR3
    @TheNiTeMaR3 5 лет назад +4

    Love that reverse integration evaluation trick! Beautiful video 😊

  • @angelmendez-rivera351
    @angelmendez-rivera351 5 лет назад +12

    You should try calculating the sum 1/1^2 + 1/5^2 + 1/9^2 + ••• + 1/(4n + 1)^2 + ••• to infinity.

    • @jadegrace1312
      @jadegrace1312 5 лет назад +7

      I imagine it's not too much more difficult because you do the same thing but you do partial fractions twice.

    • @jadegrace1312
      @jadegrace1312 5 лет назад +5

      I just did it out and got π²/16+C/2. Where C is Catalan's constant

    • @DendrocnideMoroides
      @DendrocnideMoroides Год назад

      @@jadegrace1312 Catalan's constant is written as G not C but ok

    • @jadegrace1312
      @jadegrace1312 Год назад

      @@DendrocnideMoroides Well, I am defining it as C. Plus I've seen it written as C and K before, in addition to G, so who cares. It's not like I'm doing anything weird like calling it π or something.

  • @atomiccompiler9495
    @atomiccompiler9495 5 лет назад +1

    1:29 arbitrary constants: are we a joke to you?

  • @robinpetersson5290
    @robinpetersson5290 5 лет назад +2

    Another great video from Papa

  • @brunoandrades5530
    @brunoandrades5530 5 лет назад +1

    Sexy primes is actually way funnier in spanish; cause in spanish prime numbers are translated as "números primos" where "primos" can also be translated as cousins; so sexy primes is usually understood in spanish as "sexy cousins" and cousin primes as "cousin cousins"

  • @lukemmurphy795
    @lukemmurphy795 5 лет назад +32

    See I like maths but I'm nowhere near this level haha. I'm 17 but I have started studying maths independently everyday for fun starting with the basics so hopefully I'll reach this level one day. I doubt anyone actually cares lmao, but I just wanted to say it.

    • @mountainc1027
      @mountainc1027 5 лет назад +2

      I'm 15 and still in HS, but I've already self-taught basic calculus lol
      Calculus opened my mind and introduced me to everything in a higher level, and now I consume maths and physics videos daily :)

    • @morganmitchell4017
      @morganmitchell4017 5 лет назад +2

      Yeah, I get you. I'm 19 and doing a physics degree. I like papa flammy but a lot of the stuff now seems to depend on being a higher level than I am atm. I'm not familiar with "fubini this shit" or the eta function so it makes it harder to enjoy.

    • @lukemmurphy795
      @lukemmurphy795 5 лет назад +1

      I just want to mention that my age is in between both of yours haha.

    • @skeletonrowdie1768
      @skeletonrowdie1768 5 лет назад

      welcome to this introduction! we expect great things from you.

    • @lukemmurphy795
      @lukemmurphy795 5 лет назад

      @@skeletonrowdie1768 What do ya mean? I assume I'm missing a reference.

  • @shubhamaryan8202
    @shubhamaryan8202 5 лет назад +1

    Wow your ways of solving problems are just awesome

  • @tifnatandmat
    @tifnatandmat 5 лет назад +2

    I have a fun challenge for you I did recently: Find an infinite sum for π by using the arc length of a quarter unit circle and its infinite summation definition of an arc length!

  • @SuperMiketron
    @SuperMiketron 5 лет назад +3

    I'm disappointed that sexy primes were not involved in the making of this video.

  • @gaborandomvlog9112
    @gaborandomvlog9112 5 лет назад

    i love this chanel, really much

  • @mncubing8160
    @mncubing8160 2 года назад

    I was looking for the sum of the reciprocal of the squares of the factorials. Is that a mathematical constant or can it be derived?

  • @handsomenewman6772
    @handsomenewman6772 5 лет назад

    Ey pappa, do u have any opinion on baby rudin? I've heard about this bad boi for long time and want to gear up my analysis. Have u tried it?

  • @giannismaris13
    @giannismaris13 5 лет назад +5

    Im watching black pen red pen, i know how to meth!

  • @ahmeddjekhar5442
    @ahmeddjekhar5442 5 лет назад

    Smooth and elegant

  • @paulestrada961
    @paulestrada961 5 лет назад

    I think the only other detail that was missed here was during the rushed partial fractions where you swapped the addition and subtraction sign a second after 5:25. But no matter because the correct implication was made for A=B because you were just doing your thing my boi and would be able to see the small detail if you slowed the process down. Other than that, this was an exciting video to see and I love the use of integrals and geometric series for this!! Can't wait until the next topic you will have.

  • @SydneyBorn04
    @SydneyBorn04 4 года назад

    The change of index @ 10:10, shouldn't the exponent be n-1? I'm a little confused

  • @oni8337
    @oni8337 3 года назад

    How do you know (tx)^2 is between -1 and 1

  • @micrapop_6390
    @micrapop_6390 5 лет назад

    4:17 : I can say as a french that "Voilà" is the best conclusion word ever

  • @alexschopbarteld922
    @alexschopbarteld922 5 лет назад

    Hello Pappa flammy I liked the video very much. Lately my recommendations have been filled with 50 to 100 ways to do... For example 50 ways to cook a steak. Video idea: 50 ways to do an integral?
    Keep up the good work, stay flammable.
    Alex

  • @Metroid73
    @Metroid73 5 лет назад

    One thing I find interesting about this, the sum of 1/n^2 from 1 to inf is pi^2/6 (basel problem). You could split this sum into two sums over the odd and even integers squared, ie. 1/(2n)^2 and 1/(2n+1)^2 . Intuitively you would think that the even and odd integers each contirbute to half of the full sum, ie. pi^2/12 . But from this you can see that the even integers contribute less that the odd integers since if the sum of odd integers give p^2/8 , then the even integers contibute pi^2/6 - pi^2/8 = p^2/24 , which seems wierd. I wonder if this has anything to do with the idea that in some cases you can't arbitrarily split up the terms in a sum into more sums and expect the same result when you recombine thee results after summing each one individually. Or does this imply there's a difference in the number of even and odd integers (or somthing to that effect). Would love to hear your thoughts Flammable maths, and anyone else's thoughts.

    • @smartsport
      @smartsport 5 лет назад

      Myles Scollon well since it’s 1/1+1/4+1/9, etc, the first and biggest number is an odd reciprocal, and 1/4, 1/16, etc come nowhere near reaching 1. In that way it makes sense. If the sum started with an even number, I’m sure the even-only sum would then be bigger.

  • @ilafya
    @ilafya 2 года назад

    You are the man dud

  • @korayacar1444
    @korayacar1444 5 лет назад +2

    WHO WILL WIN?
    Papa at 9:46 || Papa at 10:55

  • @georget2063
    @georget2063 5 лет назад

    Der beste Kanal auf youtube. Prove me wrong.

  • @owenl3929
    @owenl3929 5 лет назад +1

    Using the infinite sum starting at 0 of the triple integrals from ln(-1) to infinity/negative infinity (which clearly is -1) of pi factorial + abc dadbdc, I have proved the Riemann hypothesis. Sadly it’s too complicated for the average person to comprehend, so I see no reason to write it down.

  • @jkid1134
    @jkid1134 Год назад

    Thank God my favorite channel SpaceX is back up

  • @ajayjadhav873
    @ajayjadhav873 5 лет назад

    Sir what is value of sum of all factorial

  • @nellvincervantes3223
    @nellvincervantes3223 5 лет назад

    Lets do some physics boi
    An elliptical plate initially rests on a horizontal surface at position where its major axis, 4 m, is in vertical position and its minor axis, 2 m, is in horizontal position. Determine the angular velocity of the plate after it is released from rest, at position when its major axis is in horizontal position and its minor axis is in vertical position.

  • @LagAttacktoSlay
    @LagAttacktoSlay 5 лет назад +5

    10:55 I hate how you exploited n-1 into n+1... And I hate that it doesn't matter XDD

  • @x15cyberrush9
    @x15cyberrush9 5 лет назад +2

    Brehhh. I know how to meth xD

  • @alexanderboscan2087
    @alexanderboscan2087 4 года назад

    You can just come up with it using cos(x), It's like 10x easier.
    Do the same thing euler did for the basel problem but use cosine instead.

  • @dnranjit
    @dnranjit 5 лет назад

    I hear it's real hot in Germany and France..stay cool!

  • @holyshit922
    @holyshit922 11 месяцев назад

    Can be done by comparing infinite product expansion for sine and infinite sum for sine
    and tyhis is the easiest way

  • @JashanTaggar
    @JashanTaggar 5 лет назад

    BPRP punching air rn

  • @leafbaguette
    @leafbaguette 5 лет назад

    5:04 it's about here where I regret watching these videos on 2x speed

  • @tianvlasic
    @tianvlasic 5 лет назад

    2:36 In to what therms...😂?

  • @arturoruizyaringano1215
    @arturoruizyaringano1215 5 лет назад +2

    10:09 I have a question here. If you say "k+1=n" then "k" should be "n-1". Why in the video you change "k" by "n+1"? That doesn't change all the answer?

    • @robin9740
      @robin9740 5 лет назад +2

      No, since he replaces all k by n-1 it stays the same. On top of that the sum goes to infinity, 1+infinity=infinity.

    • @eliasarguello9961
      @eliasarguello9961 5 лет назад +2

      Arturo Ruiz Y yes, but it really doesn’t matter at all. (-1)^(n+1) = (-1)^(n-1). Try to see if you can prove that yourself.

    • @eliasarguello9961
      @eliasarguello9961 5 лет назад +1

      Also Robin Van Gaalen already made the second point I was going to make. The sum is still an infinite sum

  • @skeletonrowdie1768
    @skeletonrowdie1768 5 лет назад +1

    entegewal!

  • @marianorodriguez13
    @marianorodriguez13 4 года назад

    Using the mclaurin expansion of cosine you could do it much easier, but your way was way cooler

  • @3ckitani
    @3ckitani 5 лет назад

    FM: Made one small mistake
    Smart Butts: 1:28 !!!

  • @nathandaniel5451
    @nathandaniel5451 5 лет назад +1

    -(3/2)zeta(-1)π²

  • @davide467
    @davide467 5 лет назад +1

    best part = 5:02 to 5:10

  • @hassan010012
    @hassan010012 4 года назад

    I need your help, please!
    I have a series
    Sum_{k=0}^{m} (-1)^k mCk (k+n)^-1 = (m+1) (m+n)C(m+1)
    C stands for combinations

  • @uy-ge3dm
    @uy-ge3dm 5 лет назад

    Hey this is from Book of Proof!

  • @subhrajitroy1477
    @subhrajitroy1477 5 лет назад +1

    I SUPPOSE U DELIBERATELY MISSPELT 'SERIOUSLY' IN THE TITLE...RIGHT PAPA?

    • @subhrajitroy1477
      @subhrajitroy1477 5 лет назад +1

      Do u now that you are the only RUclipsr who replies to me??? Thanks Bruh!!!

  • @moritzj.5084
    @moritzj.5084 5 лет назад

    At which university do you study in Germany ?

    • @moritzj.5084
      @moritzj.5084 5 лет назад

      @@PapaFlammy69 Wie kamst du dazu dich für Potsdam zu entscheiden, wenn man fragen darf :D ? Oder war die Entscheidung primär danach gerichtet welche Uni bei dir so in der Nähe liegt ?

  • @mostafaahmednasr621
    @mostafaahmednasr621 5 лет назад

    Cant u make like a 'previously with papa flammy' thing so we can remember which videos u are referencing

    • @mostafaahmednasr621
      @mostafaahmednasr621 5 лет назад

      Aw i see m8 sorry to waste ur time, have a flammable day :)

  • @EvilGeniusIIpi
    @EvilGeniusIIpi 5 лет назад

    Thanks for the meth on my birthday Papa Flammy!

  • @thegavinjackson
    @thegavinjackson 5 лет назад +1

    "Something a first grader can do"

  • @federicopagano6590
    @federicopagano6590 4 года назад

    Ey flammy what is the sexy flammy music like a melody behind in a lot of previews. Here 0:22

  • @dannygjk
    @dannygjk 5 лет назад

    What if we don't pay you before the end of the course?

  • @edoardoprotti
    @edoardoprotti 5 лет назад

    2:31 >mfw papa tries to be a sexy boi

  • @ilovecovid
    @ilovecovid 5 лет назад

    Very impresive but can you solve 765138*1427384 mentally?

  • @pythagorasaurusrex9853
    @pythagorasaurusrex9853 5 лет назад

    "Let's Fubini this shit..." Naaaa... "Euly maccharoni" are less tasty than "Fubini al forno".

  • @giacomobontempi9112
    @giacomobontempi9112 5 лет назад

    I'm naturally start to develop a german accent

  • @sanelprtenjaca9776
    @sanelprtenjaca9776 5 лет назад

    Flammable maths, what was going on with you and #blackpenredpen?

  • @jkid1134
    @jkid1134 5 лет назад

    You said the bprp word🙊

  • @Xeroxias
    @Xeroxias 5 лет назад +1

    Damn, this video made me uncomfortable

    • @Xeroxias
      @Xeroxias 5 лет назад

      @@PapaFlammy69 5:02

  • @heisenberg_fisher2890
    @heisenberg_fisher2890 5 лет назад

    this video is absolutely awesome. a small series on dirichlet L functions and dirichlet series would be great. and also, fuck bprp fans who come and say bullshit. Simply ignore them. Papaflammy ist überlegener als bprp(correct me if the sentence is wrong)

  • @assafabram9649
    @assafabram9649 5 лет назад

    Just do eta+zetta

  • @tanvec
    @tanvec 5 лет назад

    This video, specifically because of the result, is irrational. Ba dum dum.

  • @user-ou3bf2um3r
    @user-ou3bf2um3r 5 лет назад

    I love and I don't know why hhhhh hhhhhh,

  • @taterpun6211
    @taterpun6211 Год назад

    rip old comments

  • @michaelempeigne3519
    @michaelempeigne3519 5 лет назад

    No need for any of this work in video.
    Sigma(from n=1 to inf ) 1/n^2 -(1/2)^2 *sigma(from n=1 to inf) 1/n^2
    π^2/6-1/4*π^2/6 = (3/4)*π^2/6
    = 3π^2/24
    =π^2/8

  • @JuanLopez-rl7ry
    @JuanLopez-rl7ry 5 лет назад

    I want to be a smart ass

  • @esper4605
    @esper4605 5 лет назад +1

    *seriously

    • @mattgsm
      @mattgsm 5 лет назад +1

      Do I see a woooosh?

    • @49fa75
      @49fa75 5 лет назад +2

      @@mattgsm I see a double woooosh

    • @mattgsm
      @mattgsm 5 лет назад +2

      @@49fa75 did I see a triple woooosh?

    • @49fa75
      @49fa75 5 лет назад

      @@mattgsm no u :v

  • @Polaris_Babylon
    @Polaris_Babylon 5 лет назад +1

    Seriesly Xd
    P.S.: Math is about finding unexpected connections

  • @neilgerace355
    @neilgerace355 5 лет назад

    I don't understand the reverse engineering step ... Someone please spell it out.
    Edit: I do understand Fubini-ing this shit, but I don't understand where the shit came from.