Let's solve this crazy integral quickly with a nice trick!

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  • เผยแพร่เมื่อ 28 ม.ค. 2025

ความคิดเห็น • 32

  • @DOROnoDORO
    @DOROnoDORO 2 ปีที่แล้ว +47

    The animation at 1:35 looks so nice! You should do it more often :)

    • @ryderpham2826
      @ryderpham2826 2 ปีที่แล้ว +3

      I love the transparency effect as well 🥰

  • @theartisticactuary
    @theartisticactuary 2 ปีที่แล้ว +6

    Needs some more tidying up at the end, Michael. Any ln(1/something) needs replacing with -ln(something) and any log roots need replacing with half logs. You’re getting marks docked for that.
    ln(1-half.ln(2)) - ln(half.ln(3) - ln(2)+third.root3)

  • @goodplacetostop2973
    @goodplacetostop2973 2 ปีที่แล้ว +11

    5:58

  • @abrahammekonnen
    @abrahammekonnen 2 ปีที่แล้ว +4

    That was a nice simple problem(in the grand scheme of things). Thank you

  • @dingo_dude
    @dingo_dude 2 ปีที่แล้ว +2

    loving these trigonometric integrals lately, keep it up!

  • @Dan-cw8xu
    @Dan-cw8xu 2 ปีที่แล้ว

    Substitution at its finest! NIce job.

  • @manucitomx
    @manucitomx 2 ปีที่แล้ว +3

    A case of follow your instincts.
    Thank you, professor.

  • @figur3itout307
    @figur3itout307 2 ปีที่แล้ว

    Cool problem. Thanks for the inspiration!!

  • @Alex-kp3hd
    @Alex-kp3hd 2 ปีที่แล้ว +6

    add in the numerator cot(x) and then subtract it, split the integral into 1-(cot(x)-csc^2(x))/ln(sinx) and notice that the numerator is the derivative of the denominator, so the substitution u=ln(sinx) gets it done.
    Edit: this is basically what you did, but without substituting ln(sinx)=f(x)

  • @perimetros314
    @perimetros314 2 ปีที่แล้ว

    Wolfram alpha gives us the indefinite integral of that :
    ∫(csc²(x) + ln(sin(x)))/(cot(x)+ln(sin(x)))dx
    =
    x + log(sin(x)) - log(cos(x) + sin(x) log(sin(x))) + C

  • @SuperYoonHo
    @SuperYoonHo 2 ปีที่แล้ว

    nice video!:)

  • @MacHooolahan
    @MacHooolahan 2 ปีที่แล้ว

    This video has made me wonder (phps heretically) - is there a point to the functions csc, sec, cot - and if you really want to go there... tan? Do they really justify a label?

    • @jacemandt
      @jacemandt 2 ปีที่แล้ว +3

      Tan (at least) deserves a label because if a line goes through the origin, its slope is calculated with the tangent function.

    • @MacHooolahan
      @MacHooolahan 2 ปีที่แล้ว

      @@jacemandt Fair, but I mean why introduce new labels when: tan = sin/cos, sec = 1/cos, they are not fundamental in any way - they feel like a hangover....

  • @ex9033
    @ex9033 2 ปีที่แล้ว

    Suggest me a book or pyq of the examination where I get such questions equivalent or greater level to jee advanced

  • @bronchiel
    @bronchiel 2 ปีที่แล้ว

    I never knew that f'(x)/f(x) = ln(f(x)). Never was taught such a thing. Thanks, but where does it come from?

    • @allanjmcpherson
      @allanjmcpherson 2 ปีที่แล้ว +4

      It's not that f'(x)/f(x) = ln(f(x)). Rather the RHS is an antiderivative of the LHS. You can see this by taking the derivative of ln(f(x)) using the chain rule.

    • @bronchiel
      @bronchiel 2 ปีที่แล้ว

      @@allanjmcpherson oh yeah you're right, thanks. sometimes i'm a bit slow

    • @allanjmcpherson
      @allanjmcpherson 2 ปีที่แล้ว +1

      @@bronchiel no worries. I'm sure we've all been there. I know I have.

    • @leif1075
      @leif1075 2 ปีที่แล้ว

      FUCK qhybajdnh8wnin gods name wiuld.anyone noticeable numeratornisnjust f if x minus f orime..I don't see angine seeing that at all just a lucky dirty trick and if you missnyoundont see it..surelynthere must be a logical smarter way..

  • @jacemandt
    @jacemandt 2 ปีที่แล้ว +1

    Approximately 0.672, for the record.

  • @General12th
    @General12th 2 ปีที่แล้ว

    Hi Dr.!

  • @NotoriousSRG
    @NotoriousSRG 2 ปีที่แล้ว +1

    I’m new here. Who’s the “favorite problem suggested”?

    • @stephenbeck7222
      @stephenbeck7222 2 ปีที่แล้ว +4

      Michael has a google form for people to suggest problems (in the description box of the video). Someone spams the form with a bunch of problems that end up being interesting enough for Michael to make videos with them. Their pseudonym on the form is “integral suggester” or I guess “problem suggester” now. I don’t think he knows who the person actually is.

    • @NotoriousSRG
      @NotoriousSRG 2 ปีที่แล้ว

      @@stephenbeck7222 TY!!! you rock dude

  • @jkid1134
    @jkid1134 2 ปีที่แล้ว +2

    Crushed it! What an ugly number though

    • @General12th
      @General12th 2 ปีที่แล้ว +2

      yo dawg I heard you like natural logarithms

    • @jkid1134
      @jkid1134 2 ปีที่แล้ว +5

      @@kostasbr51 would love to see a proof

  • @minwithoutintroduction
    @minwithoutintroduction 2 ปีที่แล้ว

    الفكرة رائعة و الخبير هو من سيلاحظها.
    تحية لكم

  • @축복-l1l
    @축복-l1l 2 ปีที่แล้ว +1

    asnwer=1(dx+xd)(sin-sin) 🤣🤣🤣🤣🤣