How to use Laplace Transforms to solve HARD integrals

Поделиться
HTML-код
  • Опубликовано: 5 апр 2020
  • Check out MotorMusic: • Math Bros - We Love Ca...
    outro song lyrics:
    lyrics:
    Blackpenredpen Blackpenredpen (+ C whoo)
    He's a calculus teacher, uses black and red.
    He does math for fun (integrals), diff eqs get done.
    Usin' complex numbers, doin' marathons.
    And as always, that is it.
    *specials thanks to Zach and Jonah for your amazing work!*
    integral of sin(x)/x from 0 to pi/2: • integral of sin(x)/x f...
    See Laplace marathon: • Laplace Transform Ulti...
    If you enjoy my videos, then you can click here to subscribe ruclips.net/user/blackpenredpe...
    Shop Math: teespring.com/stores/blackpen...
    Wear Math: / wear_math
    Support Math: / blackpenredpen
    Follow Math: / blackpenredpen
    More Math: blackpenredpen.com
    Blue Microphone: amzn.to/2DAbHYL
    Expo Markers (black, red, blue): amzn.to/2T3ijqW

Комментарии • 109

  • @blackpenredpen
    @blackpenredpen  4 года назад +43

    Q: what’s the integral of (cos(at)-cos(bt))/t from 0 to inf?

    • @juanmanuelmolanobaron7385
      @juanmanuelmolanobaron7385 4 года назад +9

      ln(b/a)

    • @cjalzar9114
      @cjalzar9114 4 года назад +3

      @@juanmanuelmolanobaron7385 yes

    • @kobayashi148
      @kobayashi148 4 года назад +1

      ln(b/a). Can you make a video demonstrating the parametric equations of the Cissoid of Diocles?

  • @JonahSussman
    @JonahSussman 4 года назад +41

    Thanks so much for the opportunity to write this song! We had so much fun making it :) And another great video as always!

    • @blackpenredpen
      @blackpenredpen  4 года назад +6

      Jonah Sussman
      I should be the one to say thank you! Thank you Jonah and your brother for your time, effort and creativity! It really put a smile on my face when I heard this yesterday! Thank you!!

    • @budtastic1224
      @budtastic1224 4 года назад +2

      Awesome song guys! Love the ad libs in the background... reminds me of migos

    • @JonahSussman
      @JonahSussman 4 года назад

      chico baber thank you! :)

  • @gregoriousmaths266
    @gregoriousmaths266 4 года назад +48

    Omg that outro song lmao

  • @garyhuntress6871
    @garyhuntress6871 4 года назад +34

    "life doesn't have to be that hard" - BPRP :D

    • @blackpenredpen
      @blackpenredpen  4 года назад +3

      It really doesn’t. : )))

    • @SiegfriedFafnirsbane
      @SiegfriedFafnirsbane 4 года назад +1

      @@blackpenredpen hey i really like your channnel very much.It helps me very much even though i technically only have calc 1(calc required for physics and chemistry of highschool) i still appreciate your content sir.Keep up the good work.

  • @learningbasics173
    @learningbasics173 4 года назад +1

    I have learned a lot of things from your lectures. You make complex things so easy and understandable. You are a great teacher indeed.

  • @6099x
    @6099x 4 года назад +3

    prof chow, thank you :D i love having calculus in my life, the videos lately have been really cheering me up

    • @blackpenredpen
      @blackpenredpen  4 года назад

      I am very glad to hear!! Hope all is well!

  • @zbp9541
    @zbp9541 4 года назад +1

    Goosh I was preparing for an exam in integration learning from your videos and here it commees

  • @DavesMathVideos
    @DavesMathVideos 4 года назад +10

    Well as an engineer, I really have to say I appreciate this video... Great work

    • @blackpenredpen
      @blackpenredpen  4 года назад +1

      Thanks!!

    • @DavesMathVideos
      @DavesMathVideos 4 года назад

      @@blackpenredpen you're welcome. Now that I'm under semi-quarantine I decided to start a channel to answer math questions by request. Feel free to check it out sometime

  • @williamwambua7710
    @williamwambua7710 4 года назад

    Wish you posted this videos on Laplace when i had the unit....hahaha cool stuff manh!!!!

  • @IoT_
    @IoT_ 4 года назад +3

    As a university teacher, I really appreciate your way of teaching. Your scrupulous explanations are off the charts.

    • @oilermschmaharasta2905
      @oilermschmaharasta2905 3 года назад

      Just watch this Math Channel.. very impressive
      ruclips.net/channel/UCZDkxpcvd-T1uR65Feuj5Yg

  • @maskedman8368
    @maskedman8368 4 года назад +1

    lifes so easy when i stay at home and just watch what all dis dude comes up with : )

  • @debmalyadasgupta5180
    @debmalyadasgupta5180 4 года назад +5

    Hello bprp I am a child of 14 from India and I love your videos

  • @abhirupchakraborty9027
    @abhirupchakraborty9027 4 года назад +22

    Sir you have shown us the derivative of f(x) = (x^x^x^x^...). Is this f(x) is integrable??? Wolfram Alfa can't solve the integration.
    Pls discuss about this...

    • @calcul8er205
      @calcul8er205 4 года назад +1

      Abhirup Chakraborty not an answer but an observation. f(x)= exp[-W(-lnx)] where W(x) is the Lambert W function

    • @hamsterdam1942
      @hamsterdam1942 4 года назад +4

      closed form of that function is f(x)=exp(-W(-ln(x))) where W(x) is a Lambert W function. I think you can get integral of f(x) in terms of W(x), which is non-elementary

    • @maxsch.6555
      @maxsch.6555 4 года назад +2

      @Shimmy Shai The integral of x^x can be expressed with a nice series: www.desmos.com/calculator/m7l7pxpqwc

    • @abhirupchakraborty9027
      @abhirupchakraborty9027 4 года назад

      @@maxsch.6555 Thanks a lot... 😀😀😀

    • @angelmendez-rivera351
      @angelmendez-rivera351 4 года назад +1

      Shimmy Shai *The integral of x^x really needs - no, begs - to be its own special function.*
      It really doesn't. There are virtually no applications for a function such as this, and there are no useful or straightforward generalizations you can build from this either.

  • @ozzyfromspace
    @ozzyfromspace 3 года назад

    That outro song was serious fire 🔥♥️🙌🏽😁😭

  • @eva42sh
    @eva42sh 5 месяцев назад

    loved the song

  • @user-wu8yq1rb9t
    @user-wu8yq1rb9t 2 года назад

    Great ...
    Thank you my lovely Teacher 💖

  • @cristianvilladatoro9559
    @cristianvilladatoro9559 3 года назад +1

    Hi! Where can i find examples or exercises of HARD integrals to solve with Laplace transfrom?

  • @kobayashi148
    @kobayashi148 4 года назад

    Hi, can you make a video demonstrating the parametric equations of the Cissoid of Diocles?

  • @greyconover1096
    @greyconover1096 4 года назад +1

    Could you do more Fourier series? My diff EQ professor stopped teaching.

  • @yaleng4597
    @yaleng4597 4 года назад +4

    nice song there

  • @sanujatharinda6525
    @sanujatharinda6525 3 года назад

    Amazing Content...

  • @BaoNguyen6742
    @BaoNguyen6742 4 года назад +19

    Damn this time I'm fast

    • @sadboi9706
      @sadboi9706 4 года назад +1

      Me tooo

    • @auhana4945
      @auhana4945 4 года назад

      Congrats 🎁🎁🎁🎂🎂🎈🎈🎀🎉🍌🍌🍌💩💩

  • @yarimosca2955
    @yarimosca2955 4 года назад

    Nice video, you're wonderful.
    Hi from Italy🇮🇹

    • @oilermschmaharasta2905
      @oilermschmaharasta2905 3 года назад

      Just watch this Math Channel.. very impressive
      ruclips.net/channel/UCZDkxpcvd-T1uR65Feuj5Yg

  • @kingbeauregard
    @kingbeauregard 4 года назад

    Not that I have time to play with it right now, but I bet Feynman's Technique would handle this pretty well too. Toss in a term of e^(-bte^t), which evaluates to 1 at b=0 and 0 as you approach infinity. Take the derivative and it poops out a term of -te^t, which will cancel out that pesky denominator. From there, maybe some integration by parts, then all the usual Feynman steps, and then we're done. Maybe? It might work.

    • @violintegral
      @violintegral 3 года назад

      Even simpler, just throw another variable into the argument of the cosine, say, x, and then differentiate with respect to it. Now you just have to integrate e^-tsin(tx) from 0 to ∞. Just apply IBP and then integrate with respect to t and you're done.

  • @justinpark939
    @justinpark939 4 года назад

    I was doing Laplace transforms today and yesterday and this appears while I surf through youtube.

    • @oilermschmaharasta2905
      @oilermschmaharasta2905 3 года назад

      Just watch this Math Channel.. very impressive
      ruclips.net/channel/UCZDkxpcvd-T1uR65Feuj5Yg

  • @kimveranga
    @kimveranga 4 года назад +5

    Feynman’s Technique shall also work but it took me a good 35-45 minutes to solve. It’s a good math challenge though!

    • @ericsmith1801
      @ericsmith1801 4 года назад +1

      Feynman Technique ? Isn't that the same as Leibniz's rule for differentiation under the integral sign ?

    • @bmw123ck
      @bmw123ck 4 года назад

      @@ericsmith1801 yes it is! The procedure has both names

    • @kimveranga
      @kimveranga 4 года назад

      Eric Smith It is! You start out by parameterizing the integral and then take the partial derivatives.

    • @rhversity5965
      @rhversity5965 4 года назад

      Eric Smith Yes and feynmann isn’t as cool as you think

    • @ericsmith1801
      @ericsmith1801 4 года назад

      @@rhversity5965 -- using the Laplace transform is much simpler but it still requires a clever substitution, but still simpler over all.

  • @abdelalibouchouicha1683
    @abdelalibouchouicha1683 4 года назад +2

    Please blackpenredpen teacher can you give a proof of Wilson's theorem in the lesons of algebra

  • @daculesmelbournefuentes4620
    @daculesmelbournefuentes4620 4 года назад

    Awesome 💛💚💜💙

  • @changjeffreysinto3872
    @changjeffreysinto3872 4 года назад +3

    yo lets go nice theorems

  • @user-nt9mt5br1q
    @user-nt9mt5br1q 4 года назад

    I like, that you always smile)

  • @uwiennr4686
    @uwiennr4686 4 года назад

    hmm, can i ask for u blackpenredpen .. where dstribution came from 🙏🙏 ..

  • @maalikserebryakov
    @maalikserebryakov Год назад

    So when do you use it , just for definite integrals?

  • @fernandogmail1
    @fernandogmail1 4 года назад +1

    now I know how to get common denominators

  • @oussamalasfer4860
    @oussamalasfer4860 4 года назад

    Blackpenred pen do you know vivani's theorem? I kinda get how it works but rly i don't know the use of it hope you read it >

  • @ashtonsmith1730
    @ashtonsmith1730 4 года назад +3

    I am watching this on your trig pillow 😉
    Edit one day afterwards:Also outro music at 8:27

  • @blowup2034
    @blowup2034 4 года назад

    Great explanation 👌
    Sir I need help in this volume integration problem , I struggled for hours in vain
    This is the problem
    the base of a solid is the region between the curves f(X)=(x^2) -1 and g(X) = 1-(x^2) and it's cross sections perpendicular to the X axis are equilateral triangles .find the volume of the solid. ( Ans is (16√3)/15)

    • @angelmendez-rivera351
      @angelmendez-rivera351 4 года назад

      The area of a triangle is bh/2. If the triangle is equilateral, then all three sides have measure s. Hence b = s. h can be found by doing some simple trigonometry on a 30-60-90 triangle, and it happens that h = s·sqrt(3)/2. Therefore, the area is given by [sqrt(3)/4]·s^2.
      The base of the solid was described as being enclosed by y = x^2 - 1 and y = 1 - x^2, the curves intersecting at x = -1 & x = 1. These are your boundaries of integration. The measure of the base of the triangles is, therefore, given by (1 - x^2) - (x^2 - 1) = 2 - 2x^2 = 2(1 - x^2). Hence s = 2(1 - x^2). This gives s^2 = 4(1 - 2x^2 + x^4), and the area is sqrt(3)·(x^4 - 2x^2 + 1). This is the function you want to integrate. This is because, in general, you have to find the area of whatever the cross-sectional shape is (in this case, equilateral triangles), and express it as a function of x or y, by using the information given, and then integrate said area along the axis indicated.

  • @rogerlie4176
    @rogerlie4176 4 года назад +2

    Isn't it much easier to use that a primitive function to 1/u - u/(u^2+1) is log(u) - ½log(u^2+1) =...= -½log(1+1/u^2)?

  • @TheIronCollector_
    @TheIronCollector_ 4 года назад

    Hey. Could you try the integral going from 0 to pi of cbrt(sinx)dx sometime? I know it might be a long wait.

    • @angelmendez-rivera351
      @angelmendez-rivera351 4 года назад

      I'm not even sure there is a close-form solution to this.

    • @TheIronCollector_
      @TheIronCollector_ 4 года назад

      Angel Mendez-Rivera This is a very weird graph, but I have done the maths, and there is an answer. I just want to see how he would solve it with x=0 to x=pi

  • @user-wu8yq1rb9t
    @user-wu8yq1rb9t 2 года назад

    Teacher ...
    I love this sentence: *... Link, In the description for your convenience*
    But unfortunately you don't use it any more!
    And ... Thank you for this video ❤️

  • @sajjadmridul1202
    @sajjadmridul1202 4 года назад +1

    Can u please help me finding the integral of 1/(1-tan^2x) dx?

    • @angelmendez-rivera351
      @angelmendez-rivera351 4 года назад

      Sajjad Mridul 1/[1 - tan(x)^2] = cos(x)^2/[cos(x)^2 - sin(x)^2] = cos(x)^2/cos(2x). It should be noted that cos(2x) = cos(x)^2 - sin(x)^2 = cos(x)^2 - [1 - cos(x)^2] = 2·cos(x)^2 - 1 implies cos(x)^2 = [1 + cos(2x)]/2, so cos(x)^2/cos(2x) = [1 + cos(2x)]/[2·cos(2x)] = sec(2x)/2 + 1/2. Integrating sec(2x)/2 + 1/2 should be much easier for you.

  • @doublespoonco
    @doublespoonco 4 года назад +1

    That shirt is great

  • @hurtyjames7165
    @hurtyjames7165 4 года назад

    Cosine Integral Function Sir could you please , thank you

  • @thapakaji8579
    @thapakaji8579 4 года назад +1

    More Integrals of same type please..............

    • @oilermschmaharasta2905
      @oilermschmaharasta2905 3 года назад

      Just watch this Math Channel.. very impressive
      ruclips.net/channel/UCZDkxpcvd-T1uR65Feuj5Yg

  • @manuelwiedmaier23
    @manuelwiedmaier23 4 года назад

    Is it only me or are the links missing?

  • @kntn1688
    @kntn1688 4 года назад +1

    I want big board back!

  • @MrGiancarlo36
    @MrGiancarlo36 4 года назад

    WOW

  • @hbv003
    @hbv003 4 года назад

    sir
    ... What is your name.. ??

  • @ranjeetsohanpal752
    @ranjeetsohanpal752 4 года назад

    Why dont you try some Problems on Conics,It will be fun

  • @dexter2392
    @dexter2392 4 года назад +1

    bananas

  • @GamingDragon07
    @GamingDragon07 4 года назад

    8:32

  • @CoolShade000
    @CoolShade000 4 года назад

    Do a video how you switch red and black pens when when writing on the board 😂😂

  • @jarikosonen4079
    @jarikosonen4079 4 года назад

    Maybe... but normally 0

  • @anononymousarora9929
    @anononymousarora9929 4 года назад

    I think Feynman technique is indirect application of this technique

    • @oilermschmaharasta2905
      @oilermschmaharasta2905 3 года назад

      Just watch this Math Channel.. very impressive
      ruclips.net/channel/UCZDkxpcvd-T1uR65Feuj5Yg

  • @lokendraduttjoshi9823
    @lokendraduttjoshi9823 4 года назад

    S=0 put karna tha

  • @mathssolverpoint6059
    @mathssolverpoint6059 4 года назад

    I solve this question in graduation

  • @SumitKumar-nh7xi
    @SumitKumar-nh7xi 4 года назад +1

    3rd

  • @auhana4945
    @auhana4945 4 года назад +1

    .
    ..

  • @aboudawik7973
    @aboudawik7973 4 года назад +3

    Anyone who got confused like me?
    🥴🤯🤪

  • @DonCherrysDream
    @DonCherrysDream 4 года назад +1

    2nd

  • @kaushikmahanta5923
    @kaushikmahanta5923 4 года назад

    Isn't that too trivial ? HAHA

  • @subhadipbardhan9711
    @subhadipbardhan9711 4 года назад

    I'm early