A beautiful result in Calculus: Solution using Laplace transforms ( Integral cos(x)/(x^2+1) )

Поділитися
Вставка
  • Опубліковано 17 вер 2024

КОМЕНТАРІ • 243

  • @Fematika
    @Fematika 6 років тому +434

    That was one of the funniest things I've seen all week.
    EDIT : Also, pi/e = 1, why didn't you write it like that?

    • @Bhuyakasha
      @Bhuyakasha 6 років тому +23

      pi/e = 1.15572734979

    • @Fematika
      @Fematika 6 років тому +99

      Bhuyakasha It’s an “engineering are bad at math” joke.

    • @henrebooysen2513
      @henrebooysen2513 4 роки тому +30

      Fundamental theorem of engineering

    • @harelkariv1477
      @harelkariv1477 4 роки тому +21

      By the fundamental theory of engineering, pi=3, e=2,and because we know that for large enough values of 2 2=3 we get pi=e which implies pi/e=1

  • @46pi26
    @46pi26 6 років тому +204

    Gauss, Riemann, Dirichlet, and Euler start a mathematics fight club where you beat people to death with integrals. The last man standing was papa flammy, and he wasn't even part of the club

    • @PapaFlammy69
      @PapaFlammy69  4 роки тому +18

      Damn mah boi Hunter I miss you down there in the comment section! Are you doing well?

  • @wontpower
    @wontpower 6 років тому +132

    **Flawlessly uses Laplace transforms to solve integral** **forgets the s at the end of bois**

  • @blackpenredpen
    @blackpenredpen 6 років тому +213

    LOLLLLLL at 3:30 wtf. Hahhahah

    • @EmissaryOfSmeagol
      @EmissaryOfSmeagol 6 років тому +12

      Gotta love the Roblox effects

    • @nicholasleclerc1583
      @nicholasleclerc1583 6 років тому +3

      I couldn’t even understand it !!! X D

    • @arturogonzalez6184
      @arturogonzalez6184 6 років тому +7

      the new mortal kombat game looks pretty sick :D

    • @Witiok1992
      @Witiok1992 6 років тому +4

      It was hillarious!

    • @brendanlee1707
      @brendanlee1707 4 роки тому

      Omg, my two favorite math senpais are converging in this parallelism of infinitely divergent software of youtube

  • @Beniguitar94
    @Beniguitar94 6 років тому +89

    14:18 Sure you can get that result from other integrals. For example, integral(pi/e · dx) defined from 0 to 1. I'm just being annoying ;P Great video! Really enjoyed it!

  • @danielescotece7144
    @danielescotece7144 6 років тому +47

    Flammable Maths - Abusing the linearity of everything makes me happy🤣

  • @labzioui1
    @labzioui1 6 років тому +54

    “Pure mathematics is, in its way, the poetry of logical ideas.” ~Albert Einstein !!!

    • @buttapotato1233
      @buttapotato1233 3 роки тому +1

      “And that’s why poetry is not used very often because it is completely unnecessary and complicated” - me

    • @maxwellsequation4887
      @maxwellsequation4887 3 роки тому +1

      ALBERT GODSTEIN

    • @hybmnzz2658
      @hybmnzz2658 3 роки тому +1

      @@buttapotato1233 beauty is hard to grasp

  • @Ayrton-Da-Silva
    @Ayrton-Da-Silva 6 років тому +25

    LOL you are so funny, loved the new challenger approaching joke!

  • @Soundillusions94xyz
    @Soundillusions94xyz 6 років тому +21

    I admire your mathematical ability SOOO much, keep doing what you're doing. :)

  • @SeverSpanulescu
    @SeverSpanulescu 4 роки тому +12

    For engineers: Wolfram Mathematica gives the right answer instantly. When you're in a hurry, of course. If you have some time, try it with the residue theorem.

  • @benburdick9834
    @benburdick9834 6 років тому +82

    I'm beginning to think that papa flammy is a big fan of laplace transformations...

    • @Davidamp
      @Davidamp 6 років тому +14

      He's a physicist :v

    • @somedude1666
      @somedude1666 3 роки тому +1

      That's because laplace transforms are fuc,king dope bruh.

  • @escobasingracia962
    @escobasingracia962 6 років тому +10

    Best 15 minutes of my life. Please keep doing this kinds of videos.

  • @markovuksanovic14
    @markovuksanovic14 6 років тому +37

    So according to my engineering calculations, the result of this integral is obviously 1.

  • @ThAlEdison
    @ThAlEdison 6 років тому +25

    I would've combined 𝜋/2(s/(s²-1)-1/(s²-1)) into 𝜋/2((s-1)/(s²-1))=𝜋/2(1/(s+1))

  • @diegopablogordillovaras106
    @diegopablogordillovaras106 6 років тому +3

    Wow. My mind flew across mathematical lightyears! I think my calculus was really getting a little rusty. Thank you! I just got smarter just by watching this video. Instant subscription!

  • @w.s8605
    @w.s8605 5 років тому +25

    at the end of the video you wrote ( thank you

    • @tomkerruish2982
      @tomkerruish2982 4 роки тому

      It's supposed to be a heart, turned sideways.

    • @ahuman6546
      @ahuman6546 4 роки тому +2

      @@tomkerruish2982 r/wooosh

  • @soliscrown1272
    @soliscrown1272 6 років тому +4

    Great video! Very elegant solution.

  • @RockNostalgic
    @RockNostalgic 6 років тому +2

    This Integral could also be solved by residue theorem very elegant. With this approach you can almost read off the result from the definition ;)

  • @omarbaratelli3831
    @omarbaratelli3831 6 років тому +2

    Hi Flammable Maths... I think we can do more simpler... because the Laplace transform of I(t) is just (pi/2)* (s - 1)/(s² - 1) which is (pi/2)*(1/(s+1)). Therefore, using the linearity of the inverse Laplace transform, we obtain that I(t)=(pi/2)*L^(-1) {1/(s+1)}(t) = (pi/2)*exp(-t). Since I=2*I(t=1) we have: I=2*(pi/2)*exp(-1)=pi/e and we're done. Have a nice week-end :)

  • @lenoel7666
    @lenoel7666 6 років тому +1

    Mach weiter so, immer eine Freude ein neues Video von dir zu sehen.:)

  • @GermanSnipe14
    @GermanSnipe14 6 років тому +23

    God math was interesting but it's so much more interesting when memes are integrated within the teaching MMMMMMMMMMMMMMMM YUM

  • @blazep5881
    @blazep5881 6 років тому +9

    Flammy always wins

  • @TrickingSeba
    @TrickingSeba 6 років тому +1

    Durch Zufall auf deinen Kanal gestoßen und innerhalb von paar Tagen alle Videos geguckt.
    Bitte mach weiter so :^)

  • @iuribachnivsky3022
    @iuribachnivsky3022 5 років тому +1

    Aww, I first read about this back in....2001? This is one of the coolest integrals ever.

  • @Jose-vp3gb
    @Jose-vp3gb 5 років тому +3

    Im finishing my semester and all its going crazy, but 3:30 really made me laugh af. Thanks man!!!!!!!!

  • @nullplan01
    @nullplan01 6 років тому +29

    You know, you could have simplified the (s - 1)/(s² - 1) before doing the inverse Laplace transform. Might have been simpler...

    • @gamma_dablam
      @gamma_dablam 4 роки тому

      Assuming s =/= 1

    • @Charles.Wright
      @Charles.Wright 4 роки тому +1

      @@gamma_dablam - that's implicit

    • @chazzaca
      @chazzaca 4 роки тому +1

      I was thinking the same thing!! The above equations from FG implies s ^= +-1 and that he only needed to take the inverse LT of 1/(s+1) which reduces to 1/e^t. In addition, if you're going to use a Laplace Transform why not replace cos(x) as Re(e^(ix)) from Euler's formula?

    • @frenchimp
      @frenchimp 2 роки тому

      @@gamma_dablam This has already been assumed!

  • @Giganesh_exe
    @Giganesh_exe 4 роки тому +1

    So it equals 1! That's so beautiful

  • @gammaknife167
    @gammaknife167 6 років тому +117

    pi/e? Isn't that just 1?

    • @TrickingSeba
      @TrickingSeba 6 років тому +44

      And sin(x) = x , it's trivial

    • @tobiasgorgen7592
      @tobiasgorgen7592 6 років тому +29

      Ah i see, an Engineer aswell

    • @TrickingSeba
      @TrickingSeba 6 років тому +11

      Tobias Görgen Yes i study chemical engineering and you?

    • @V-for-Vendetta01
      @V-for-Vendetta01 6 років тому +4

      I don't get it, why is it a joke that engineers are bad at math? XD

    • @tobiasgorgen7592
      @tobiasgorgen7592 6 років тому +5

      Civil Engineering

  • @alexander51413
    @alexander51413 6 років тому +17

    At 11:56, can't you simplify the expression to pi/2 * (1/(s+1)) and avoid all of the hyperbolic stuff

    • @kummer45
      @kummer45 2 роки тому

      I was about to contour integrate. Considering f(z)....:3

    • @Noam_.Menashe
      @Noam_.Menashe 2 роки тому

      @@kummer45 The contour integral is very literally two steps.

  • @EmissaryOfSmeagol
    @EmissaryOfSmeagol 6 років тому +1

    Hey man, nice vid! That is a really nice result.

  • @kummer45
    @kummer45 2 роки тому +2

    With all honesty I wish you become a doctoral degree in mathematics and achieve a great contribution in this field. You deserve this. You are a natural teacher. Your content worth. It helps people get interested in this discipline.
    Besides, I think math is more than just a discipline.....

  • @debajyotisg
    @debajyotisg 6 років тому

    At @12.55 we could get a faster result by simplifying the expression in s to get ~ 1/(s+1), the IL of which is exp(-t) .
    This is such a great video. Good job.

  • @nilenninju4709
    @nilenninju4709 5 років тому +3

    Flammy: "Sooo now wee can plug every thing in"
    Me: 😃

  • @Jack__888
    @Jack__888 6 років тому +1

    My favourite youtube channel ever

    • @mihaiciorobitca5287
      @mihaiciorobitca5287 6 років тому

      Flammable Maths i would be sooo happy if you could be my teacher

  • @kqp1998gyy
    @kqp1998gyy 4 роки тому +1

    Beautiful

  • @user-wu8yq1rb9t
    @user-wu8yq1rb9t 2 роки тому

    *Papa Bruce Lee* (min: 3:15)
    Thank you so much dear Papa, great.
    I learned and enjoyed.

  • @FernandoVinny
    @FernandoVinny 6 років тому

    Absolutely beautiful, elegant and surprising!

  • @user-wj3hg8br4t
    @user-wj3hg8br4t 6 років тому

    Thank you for showing wonderful Calculus technique!

  • @Manish-uk2ow
    @Manish-uk2ow 4 роки тому

    You did it beautifully

  • @rockybond42
    @rockybond42 6 років тому +3

    3:00 bis 3:45 ist der beste Witz, dass ich in einem Mathevideo gesehen habe.

  • @matematicasemplice
    @matematicasemplice 3 роки тому

    Sehr schön! Gratulierungen!

  • @kedarbahulkar189
    @kedarbahulkar189 4 роки тому +1

    Amazing . Thank you

  • @willthescienceguy
    @willthescienceguy 5 років тому +3

    12:40 "What are thooooooose" :)

  • @skeletonrowdie1768
    @skeletonrowdie1768 6 років тому +2

    thanks for showing how to do the inverse laplace transform! It really is like integrating, because you know the integral by knowing it's derivative. In this case, you know the inverse laplace transform because you know the laplace transform of the result. Pff haha.

  • @chessandmathguy
    @chessandmathguy 6 років тому

    Beautiful. Absolutely beautiful.

  • @kennypatel3985
    @kennypatel3985 3 роки тому

    Thanks a lot! the way you explained is awesome

  • @pronaybiswas7524
    @pronaybiswas7524 6 років тому

    love this channel

  • @CDChester
    @CDChester 6 років тому +6

    THE SPICY MEMES MUH BOIIIIIIS!!!!!!!!!!

    • @CDChester
      @CDChester 6 років тому +1

      "That's hard to say .. Laplace Transformation." *Goes on saying it like 12 times quickly without batting an eye*

  • @Ideennot
    @Ideennot 6 років тому +1

    Thanks for this!

  • @철-l3n
    @철-l3n 6 років тому

    Amazing. I think this technique can be the key idea to previous videos.

  • @Mr_Mundee
    @Mr_Mundee 8 місяців тому

    for the pdf, you can just do a/(x^2 + 1) + b/(x^2 + s^2) bcz it's just product of linear equations in terms of x^2 so u made ur life a bit harder there

  • @Mr_Mundee
    @Mr_Mundee 9 місяців тому

    ur not a mathematician, you're a mathematician AND a comedian

  • @thomassinha5301
    @thomassinha5301 5 років тому +1

    Oh yeah? What about the integral from 0 to pi/e of 1?

  • @gnikola2013
    @gnikola2013 6 років тому +6

    4:20 Nice and fine? You mean cool and good

  • @JustSimplySilly
    @JustSimplySilly 6 років тому

    That was a good fight at 3:30. Keep it up.

  • @danielkirilov8065
    @danielkirilov8065 6 років тому +1

    I just imagine myself at the corner of the room, watching you kicking the air :^D

  • @j2011j2015j
    @j2011j2015j 6 років тому

    I love your videos it brings back happy memories from University

  • @dibendupal3865
    @dibendupal3865 6 років тому +1

    Sir you can do the partial fraction work easily by taking x^2=some variable u and can apply the same partial fraction as no x term is present

  • @taeim9197
    @taeim9197 6 років тому

    You can just use this: 1/(AB) = (1/(B-A))(1/A - 1/B) without solving (Ax+B)/(x^2+1) + (Cx+D)/(x^2+s^2) = 1/((x^2+s^2)(x^2+1))

  • @joaquin6719
    @joaquin6719 3 роки тому

    Nais video, specially min 3:00

  • @arsenmingo62
    @arsenmingo62 3 роки тому

    The general solution is pi/e^a (for cos(ax))

  • @dr.merlot1532
    @dr.merlot1532 5 років тому +1

    Hahaha, you showed that dominated convergence theorem who is boss!

  • @silasrodrigues1446
    @silasrodrigues1446 6 років тому +2

    Where do you bring these solutions from? You're amazing!

  • @jameswilson8270
    @jameswilson8270 6 років тому

    Awesome solution!

  • @KalikiDoom
    @KalikiDoom 6 років тому

    truly amazing!

  • @thomasblackwell9507
    @thomasblackwell9507 2 роки тому

    That’s right, they are coming for you, but with giant butterfly nets!

  • @arsenmingo62
    @arsenmingo62 3 роки тому

    I just used Leibnitz's method of integration.

  • @juandiegoparales9379
    @juandiegoparales9379 4 роки тому +2

    Dude, I'm really interested to domain this theme (the Laplace transform), could you tell, which should be the things I need to study to have good bases when I start to study this heavily?

  • @danielmilyutin9914
    @danielmilyutin9914 5 років тому

    Cool. I've noticed one thing to simplify.
    s/(s²-1) -1/(s²-1)=1/(s+1) =~> exp(-t)

  • @sajidrizvi4665
    @sajidrizvi4665 6 років тому +1

    That fight tho! :)

  • @Mike-dr1hz
    @Mike-dr1hz 6 років тому

    I appreciate the memes, my man. I'd be pleased if you salted my dish, bartender

  • @damiandassen7763
    @damiandassen7763 6 років тому

    0:20 whoooaaaah savage mathematian

  • @MrTereres
    @MrTereres 6 років тому +2

    What about the integral of sinx/(x^2+1) from 0 to infinity? Can it be expressed in terms of π, e or other known constants? I did a little search on the net and I found only numerical approximations to it, not an exact value. Also, trying the same approach as this video, it leads to ln(s)/(s^2-1) and I have no idea what is the inverse Laplace transformation of this one. Any idea if we can proceed from here or do we need a different approach for this one?

    • @MrTereres
      @MrTereres 6 років тому +1

      Thanks for the immediate response! Appreciated! I really wish you try it if you find the time. :)

    • @omarbaratelli3831
      @omarbaratelli3831 6 років тому

      Hi :) if you want the exact value of the integral of sin(x)/(x^2+1) from 0 to +infinity you should use the Exponential integral function Ei and then the exact value is just (Ei(1)-e^2*Ei(-1))/2e where Ei is not an elementary function but a special one... and so no results can be obtained in terms of real numbers like pi, e or other known constants. I hope this helps you. Bye :)

  • @ericl8743
    @ericl8743 5 років тому

    You make me miss mathematics courses!

  • @deepeshmeena3117
    @deepeshmeena3117 6 років тому +8

    new challenger approaching lol

  • @lionelinx7
    @lionelinx7 6 років тому +1

    cool bro

  • @valentinandrada9340
    @valentinandrada9340 5 років тому

    10:50 i have a question. can u realy say that sqrt(s^2)=s? s is a complex number by definition of Laplace Transforms. I dont remember, but maybe it's related to Re (s)

  • @danielhaselbauer2549
    @danielhaselbauer2549 6 років тому +3

    Do it with feyman technique :)

  • @FuhrerShattercore
    @FuhrerShattercore 6 років тому +1

    Laplace baked us a pi/e and it was delicious
    Oh btw what do you do for a living aside from making YT videos?

  • @WhisDragonBallSuper
    @WhisDragonBallSuper 4 роки тому +1

    Do it again with residu theorem but in only 3 minutes

  • @travorliu1192
    @travorliu1192 4 роки тому

    It is also possible by looking up Fourier transform table

  • @RetsamX
    @RetsamX 6 років тому +1

    The new smash bros looks amazing!
    I love these types of videos

  • @Origamiztec
    @Origamiztec 6 років тому +1

    Bro, I love to work with these videos when I understand them, and just watch in awe when I don't. What level of math or physics are laplace transforms taught? Max I've learned so far is Multivariable Differential Calculus and Physics C

    • @orangeguy5463
      @orangeguy5463 6 років тому +2

      At my university Laplace transforms are introduced in Differential Equations because of their phenomenal way to transform high order constant coefficient differential equations into algebraic problems (as long as initial conditions are known). Laplace and Fourier transforms are explored more in depth in higher level (graduate or senior level undergraduate) complex analysis classes.

  • @hoseinshooryabi3318
    @hoseinshooryabi3318 2 роки тому

    Very nice

  • @hach1koko
    @hach1koko 4 роки тому

    12:00 you could have simplified that further, s/(s^2-1)*pi/2*(1-1/s)=pi/2*s(s-1)/(s(s^2-1))=pi/(2(s+1))

  • @danielkirilov8065
    @danielkirilov8065 6 років тому

    :^> You were on a pretty hard drugs after the 3rd minute, I admire you, Math God.

  • @AndDiracisHisProphet
    @AndDiracisHisProphet 6 років тому +17

    But is it rational?^^

    • @AndDiracisHisProphet
      @AndDiracisHisProphet 6 років тому +5

      Me neither :D

    • @AndDiracisHisProphet
      @AndDiracisHisProphet 6 років тому +4

      Were is Peyam when you need him? Doing something about the Chebyshev boi....

    • @angelmendez-rivera351
      @angelmendez-rivera351 5 років тому +8

      π is approximately 3
      e is approximately 3
      Therefore, π/e is approximately 1.
      1 is rational
      Therefore, π/e is rational.
      Q.E.D.
      ;)

    • @constantin159753
      @constantin159753 5 років тому +8

      @@angelmendez-rivera351 Papa Euler would like to know your location

  • @Jack__888
    @Jack__888 6 років тому +1

    Such an amazing boi, isn't he? ☻

  • @Nemesis096117
    @Nemesis096117 5 років тому +1

    Hahahahahahahahahahahaha that was a pretty hard fight. ..😂

  • @xhourglazzezx
    @xhourglazzezx 6 років тому

    This is amazing. 😍

  • @HilbertXVI
    @HilbertXVI 6 років тому

    This is fucking amazing

  •  6 років тому

    Math-ninja-papaflammy is just awesome. Thou avoid some ChuckNorris-substitution if I can say ...

  • @temurson
    @temurson 6 років тому

    You make great videos man, that really helps me learn new things. I am only the beginner, so could you please give me a clue my can't we change the order of integration so easily? Just tell what topic I need to read, no need to tell the whole story. Thx.
    BTW: best animation I've ever seen

  • @areebuddinphundreimayum9839
    @areebuddinphundreimayum9839 6 місяців тому

    Why don't you use lagrange interpolation to find the partial fraction decomposition quickly?

  • @paulobessa563
    @paulobessa563 5 років тому

    I’ve really loved the fight, don’t get me wrong, but next time, please, be explicit with the measure tools. Or you can just use residue. Nice videos, boi.

  • @chriswinchell1570
    @chriswinchell1570 3 роки тому

    Nice. I do think think you risk a hernia from all that heavy lifting. I thought you were just gonna make cos(x) into e^(jwx), recognize this as Fourier transform of Cauchy, set w=1, taste victory, and get drunk.

  • @chaos4785
    @chaos4785 6 років тому +1

    Soooo coool😍

  • @jackvernian7779
    @jackvernian7779 6 років тому +1

    since you integrate both integrals from 0 to inf I think that is the main reason why order of integration doesn't matter. Correct me if I'm wrong, cheers!

    • @Harryjackgross
      @Harryjackgross 6 років тому

      Uniform continuity

    • @jackvernian7779
      @jackvernian7779 6 років тому +1

      +Harry Gross
      well of course, without uniform continuity it wouldn't hold.

    • @Harryjackgross
      @Harryjackgross 6 років тому

      Not always true

    • @jackvernian7779
      @jackvernian7779 6 років тому

      how so?

    • @Harryjackgross
      @Harryjackgross 6 років тому +2

      In some cases swapped limits can 'coincidentally' match when we do not have uniform continuity, in the same way that the limits of two sequences can match without the sequences being inherently related.

  • @ferchoalmeida1
    @ferchoalmeida1 6 років тому

    Great video

  • @vvladgfhjkm
    @vvladgfhjkm 6 років тому

    Boy, you rock!