A log trig integral with a beautiful result

Exactly what the title says...
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Пікірлер: 33

  • @dhibaid3578
    @dhibaid35789 күн бұрын

    Use properties of definite integrals, replace θ by (π/2 - θ) and add both I. Pretty straight forward and easier haha.

  • @maths_505

    @maths_505

    9 күн бұрын

    Oh yeah 😂 but this is more fun

  • @user-lu6yg3vk9z

    @user-lu6yg3vk9z

    8 күн бұрын

    @@maths_505why didn’t u use kings property?

  • @famillemagnan1313

    @famillemagnan1313

    8 күн бұрын

    Much easier indeed!

  • @manjugangwar7245

    @manjugangwar7245

    7 күн бұрын

    I used the same

  • @nerden1549
    @nerden15498 күн бұрын

    Love when he writes π as a и with - on top of it

  • @vladthemagnificent9052

    @vladthemagnificent9052

    8 күн бұрын

    ln, sin, and tan also looks like lu siu and tau

  • @orionspur
    @orionspur9 күн бұрын

    Replacing theta with x, the curve is symmetric with respect to the segment from (0,2) to (pi/2,0), so the area of that triangle is pi/2.

  • @gabrielerizzoo
    @gabrielerizzoo7 күн бұрын

    i encountered this integral in school: integral from 0 to 1 of xe^x, i obviously solved it using integration by parts and it resulted in 1 but i tried to generalize it using a parameter alpha in the exponent of x so i got the integral of x^alpha*e^x but i'm not smart enough to solve it and i would love to see it in one of the next videos. also i love watching your videos, especially at night since they're so relaxing and they help me falling asleep. great work! keep it up

  • @Anonymous-Indian..2003
    @Anonymous-Indian..20039 күн бұрын

    Ohh man just replace θ by (π/2 - θ) And then add both. You'll get, 2 I = ∫ { ln(tan²θ) / ln(tanθ) }dθ = ∫ 2 dθ = π I = π/2

  • @MrWael1970
    @MrWael19709 күн бұрын

    This is gorgeous, thank you very much.

  • @rohitashwaKundu91
    @rohitashwaKundu919 күн бұрын

    Some people are somehow not happy with you not using that easy 2 liner solution. But (at least to me), this one was way more fun. I think sometimes, the way matters more than the result. And Ik it's better to have a simple solution, but still sometimes the complex one is the one which actually seems interesting and more fun. So thanks!

  • @maths_505

    @maths_505

    9 күн бұрын

    Thanks for getting it homie

  • @SussySusan-lf6fk

    @SussySusan-lf6fk

    7 күн бұрын

    Yep 😊

  • @leroyzack265
    @leroyzack2659 күн бұрын

    A wild integral representation of pie.

  • @ericthegreat7805
    @ericthegreat78058 күн бұрын

    Basically this is saying the magnitude of sin2theta relative to tantheta along the first quadrant changes by a rate of pi/2 (up to a constant).

  • @justdoingmath292
    @justdoingmath2929 күн бұрын

    The integral reduces to int(1)dx from 0 to pi/2 using King, Log, and Trig properties without substitution.

  • @Haxislive766
    @Haxislive7668 күн бұрын

    Here's the solution in 3-4 line -- I= ∫ [ (stuff) -1+1]d∅ now take lcm With -1 U will find inside logarithms upstairs ln(sin2∅) Downstairs ln(tab∅) You have listen about The KINGS rule apply to the above integral and you will find the integral collapse 0 , ∫d∅ from π/2to 0 = π/2 ans

  • @kingzenoiii
    @kingzenoiii9 күн бұрын

    Greetings Kamal, i also forget how to talk from time to time 😂😂

  • @mikecaetano
    @mikecaetano8 күн бұрын

    At the point where you expand by e^x/2 (9:08), the integrand readily becomes sech(x/2) when multiplied by 2. 1/2Integrate[Sech[x/2], x,-infy,infy] Nevertheless, the z-substitution afterward was nifty.

  • @3manthing
    @3manthing7 күн бұрын

    It's all making sense now, the Black speech of Mordor, sounded very scary when I was a child, cause it was all maths.😁 I even got some hints for this to be true at school, when writting a test, and I looked to my neighbours test for a second, the teacher gave me a nasty look, and said "I see yooouuu."😅

  • @HeyKevinYT
    @HeyKevinYT9 күн бұрын

    Another dope integral representation of π

  • @perlin11
    @perlin119 күн бұрын

    Using the change of variable u=pi/2 - thêta, and addint it to the initial integral leads to the results much faster. (A bit frustrated for you not using it)

  • @davidblauyoutube
    @davidblauyoutube9 күн бұрын

    Nice!

  • @maths_505

    @maths_505

    9 күн бұрын

    Thanks mate

  • @CM63_France
    @CM63_France9 күн бұрын

    Hi, "ok, cool" : 1:11 , 1:56 , 2:29 , 3:46 , "Terribly sorry about that" : 4:55 , 6:31 .

  • @bandishrupnath3721
    @bandishrupnath37219 күн бұрын

    i didnt understand the part where u say as x is an odd function but the others are even functions ,due to even f(x) the integral converges to zero from negative to positive infinity

  • @giuseppemalaguti435
    @giuseppemalaguti4359 күн бұрын

    Mi sembra troppo semplice 2I=Int(2)dx(0...π/2)=π..I=π/2

  • @rageevanthaneswaran4659
    @rageevanthaneswaran46599 күн бұрын

    Is there any textbook for these kimd of question

  • @faaiz6672
    @faaiz66729 күн бұрын

    Which country are you from? Your are videos are so good

  • @maths_505

    @maths_505

    9 күн бұрын

    I'm from Pakistan

  • @SuperSilver316
    @SuperSilver3169 күн бұрын

    No beta function??, are you okay??

  • @trelosyiaellinika

    @trelosyiaellinika

    8 күн бұрын

    😂