How to Integrate ln(x)?

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  • Опубліковано 22 тра 2024
  • What is the integral of ln x? We apply integration by parts to solve this because it is a product of functions, where ln x multiply by 1 dx.
    We first select ln x as 'u', and 1 dx as 'dv'. Then, we take the derivative of 'u' in terms of dx, and take the integral of 'dv'. Finally, plug them into the formula of integration by parts and we got ' x ln(x) - x + C ' as our final answer.
    INTEGRATION BY PARTS EXPLANATION: → • Integration By Parts F...
    TIMECODES:
    0:00 → Intro
    0:13 → Why Integration By Parts is used?
    0:34 → Selection of u and dv
    1:15 → Derivative of u & Integral of dv
    1:50 → Plug in the terms into formula
    2:26 → We did it!

КОМЕНТАРІ • 23

  • @IAmAPeti
    @IAmAPeti Місяць тому +5

    ln ❌️
    lawn ✅️

  • @pauselab5569
    @pauselab5569 4 місяці тому +5

    My first thought is to use u sub. Let x=e^u, dx=e^udu Then we have integral(ln(x)dx)= integral(e^u*udu) and then integration by parts which clearly simplified because of exponential.

  • @mtaur4113
    @mtaur4113 3 місяці тому

    This is less commonly done and has higher prerequisites, but you could write out ln(x) as integral 1 to x of 1/t dt, and reverse the order of integration. You might have to set up the outer integral as a definite integral, such as int_1 to x of ln(s) ds, so you have a concrete region for Fubini to work with.
    This definite form is an antiderivative of ln, with a specific "+C" built in, which you can rewrite in a simplified form with a generic +C absorbing any unnecessary constants when stating the general antiderivative we were looking for. I got a +1 I didn't need when I did this.

  • @icafe36485
    @icafe36485 4 місяці тому +1

    Hello, sorry, what software do you use to make this video?

    • @YeahMathIsBoring
      @YeahMathIsBoring  4 місяці тому +3

      I only use Microsoft PowerPoint as visual display, and Microsoft CLIPCHAMP as voiceover and merge it with the PPT slides.

    • @icafe36485
      @icafe36485 4 місяці тому +1

      Thank you🌹

    • @YeahMathIsBoring
      @YeahMathIsBoring  4 місяці тому +1

      @@icafe36485 You're welcome

  • @idkyet9458
    @idkyet9458 6 місяців тому +15

    why not DI method
    D I
    + lnx 1
    - 1/x x
    since -(1/x)(x) can be integrated stop there
    then you get
    ∫lnx dx = xlnx - ∫(1/x)(x) dx
    = xlnx - x + C

    • @YeahMathIsBoring
      @YeahMathIsBoring  6 місяців тому +6

      Yeah, that's true. DI method can also be used to get the answer. The one I've used here is just a normal IBP.

    • @RebornKaotic
      @RebornKaotic 3 місяці тому +6

      its the same process bro

    • @DaanHun
      @DaanHun 2 місяці тому +3

      DI method is just a way to write down IBP right? same thing.

  • @user-xr6zh5cd4z
    @user-xr6zh5cd4z 22 дні тому

    Isn't it ILATE instead of LIATE

  • @mugengabertrand6891
    @mugengabertrand6891 Місяць тому

    Help me in his question Cos^3xdx by using integration by party

    • @Loots1
      @Loots1 17 днів тому +1

      Why?
      [ cos^(2)x][cosx]
      [1-sin^(2)x][cosx]
      Set your u=sinx
      There is no needfor integration by parts

  • @mathsfamily6766
    @mathsfamily6766 4 місяці тому

    very nice Integral! can you please show me by another way?

    • @YeahMathIsBoring
      @YeahMathIsBoring  4 місяці тому +1

      Thanks! Another way to find the integral without performing integration by parts is to use the DI Method, in which we will still be getting the same answer.

    • @mathsfamily6766
      @mathsfamily6766 4 місяці тому

      oh! i got it.thanks sir!@@YeahMathIsBoring

  • @user-nd7th3hy4l
    @user-nd7th3hy4l Місяць тому

    J=xlnx-x+k

  • @ragedgamer2850
    @ragedgamer2850 3 місяці тому

    integrate (x^n (lnx)^n )

  • @godisalive6685
    @godisalive6685 5 місяців тому +1

    Lol that AI VOICE IS CRACKING ME UP😂😂

    • @YeahMathIsBoring
      @YeahMathIsBoring  5 місяців тому +1

      It's voiceover generated from text by using MICROSOFT CLIPCHAMP.

    • @godisalive6685
      @godisalive6685 5 місяців тому +1

      @@YeahMathIsBoring ya Ik it's text to speech but the ai voice over kinda failed to pronounce word ln that's where It got me

    • @YeahMathIsBoring
      @YeahMathIsBoring  5 місяців тому +1

      @@godisalive6685 😂😂