Power series differentiation (KristaKingMath)

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  • เผยแพร่เมื่อ 19 ธ.ค. 2024

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  • @whackedout101
    @whackedout101 9 ปีที่แล้ว +13

    I have a question though, why don't you change the bounds of the summation once you change all the n's to (n+1)

  • @waltwilliams1770
    @waltwilliams1770 8 ปีที่แล้ว

    My college textbook is not very clear on how to preform this procedure. It took a couple times of replaying the video but now I see what is going on. In places where the denominator, or perhaps the whole function, of 1/(1+x) is surrounded by a power we can take the derivative on the 'x' within the sum representation of the simpler, known, form of function to get the sum representation of function where the denominator of 1/(1+x) is surrounded by a power. (I hope that made sense)
    Its apparent that you love mathematics in that you started a web site so you can do what you love. Keep it up.

  • @johnfraser8158
    @johnfraser8158 9 ปีที่แล้ว +17

    You took the derivative of the series but you didn't say one word about indexing the starting value of n.

  • @magicguy1988
    @magicguy1988 10 ปีที่แล้ว +3

    An easier way to differentiate 1/(1+x) is rewrite it as (1+x)^(-1), then d/dx[(1+x)^(-1)] becomes as simple chain rule problem. Which, would give -1(1+x)^(-2) or -1/(1+x)^2. I always prefer to use the chain rule whenever possible because it is so much simpler to use than the product rule or quotient rule

  • @myrtyltheTURTLE
    @myrtyltheTURTLE 9 ปีที่แล้ว +2

    Great and thorough explanation. Much appreciated.

  • @whackedout101
    @whackedout101 9 ปีที่แล้ว

    Oh my goodness gracious. Thank you so much for making these videos. I am struggling so much in calculus 2 class in college because I have my instructor is so bad and after watching your video, I finally understand all the steps! Thank you so much!

    • @kristakingmath
      @kristakingmath  9 ปีที่แล้ว

      You're welcome, I'm so glad that it's finally making sense!

    • @whackedout101
      @whackedout101 9 ปีที่แล้ว +1

      integralCALC But I am confused though at one thing. I feel like you have to change the index when you want x^(n-1) to x^n.

  • @MultiMathtutor
    @MultiMathtutor 10 ปีที่แล้ว +4

    In the first example, it doesn't make any difference because the first term is zero. But in general, if you change n to n+1 you also need to change the index to n+1=0. So the summation should start at n=-1. Am I right?

    • @martaflothmann-alpar1534
      @martaflothmann-alpar1534 7 ปีที่แล้ว

      You are right. The starting value of n should have been n=1 after the differentiation since the constant term became 0. Then after the re-indexing it should have gone back to 0. None of that was mentioned in the video.

    • @matrixate
      @matrixate 6 ปีที่แล้ว

      Yes, f(n) has an additive inverse sum to the index n=a. So, if f(n) becomes f(n+c) then the index n starts at n=a-c. The same works the other way.

  • @aaronchow2366
    @aaronchow2366 9 ปีที่แล้ว +2

    Great Video! Love all of these thanks for all you do!

  • @fatimaosman8584
    @fatimaosman8584 9 ปีที่แล้ว

    This is just Awesome! Thank you so much. This topic is one of the hardest in Calculus.

    • @kristakingmath
      @kristakingmath  9 ปีที่แล้ว

      Fatima Alamin You're welcome, I'm so glad it helped!

  • @qwe12353
    @qwe12353 10 ปีที่แล้ว

    why don't you multiply -1 to nx^n-1 at 8:15?

  • @PetStuBa
    @PetStuBa 6 ปีที่แล้ว

    omg you wonderful .. one of the best teachers ever ... very clear :)

  • @biggerthaninfinity7604
    @biggerthaninfinity7604 4 ปีที่แล้ว

    Amazing explanation! Thank you sm!

    • @kristakingmath
      @kristakingmath  3 ปีที่แล้ว

      You're very welcome, Bigger, I'm so glad you liked it! :D

  • @BelieverStarcraft
    @BelieverStarcraft 8 ปีที่แล้ว

    I am not sure if I am just dumb but since the infinite series starts at n=0, shouldn't it be (-1)^(n+1) instead of (-1)^(n)? What am I missing here?
    Respectively when you take the derivative , the signs inherently change in the series, wouldn't it then convert two in the derivative to (-1)^(n) because the series starts with a negative value?

  • @saintous94
    @saintous94 10 ปีที่แล้ว

    Thanks for making these videos, they have helped me so much. One question though, once you get the value of the indefinite integral is it possible to find a value or assign a number to C? Or If you just leave C is okay? Thanks in advance

    • @kristakingmath
      @kristakingmath  10 ปีที่แล้ว

      You can if you've been given an initial condition like y(0)=5. When you have an initial condition that you can use to find C, it's called an initial value problem. In this example, you'd just plug in 0 for x and 5 for y, and that would allow you to solve for a value of C. Hope that helps!

  • @hindali5247
    @hindali5247 8 ปีที่แล้ว

    There is no better than that. I hope to be as awesome as you are!

  • @StraightAnthony
    @StraightAnthony 10 ปีที่แล้ว

    is this the same as term by term differentiation?

  • @hamisiwenge1369
    @hamisiwenge1369 9 ปีที่แล้ว

    thanks so much always you do at your level best very helpful to me

  • @shawndelmay9525
    @shawndelmay9525 7 ปีที่แล้ว

    Amazing very detailed thank you

  • @yogendravishwakarma5592
    @yogendravishwakarma5592 5 ปีที่แล้ว

    What a magic mam!!! Would you like to tell me how to find sum of any finite series??

  • @alfa_q
    @alfa_q 8 ปีที่แล้ว

    Finally, an explanation in plain English that actually makes sense \[T]/

  • @XxM4g1CxQUANxX
    @XxM4g1CxQUANxX 7 ปีที่แล้ว +1

    you may have just saved my calculus grade

  • @kingsleybenjaminobika2301
    @kingsleybenjaminobika2301 8 ปีที่แล้ว

    Wow! You are awesome!

  • @wowokole
    @wowokole 6 ปีที่แล้ว

    FUCKING THANK YOU

  • @usix123
    @usix123 8 ปีที่แล้ว +1

    not trying to be mean, but your demonstration/explanation is quite confusing.

  • @xolanimavuso6989
    @xolanimavuso6989 10 ปีที่แล้ว

    .

  • @shadowxelnaga
    @shadowxelnaga 10 ปีที่แล้ว +1

    A piece of advice: you should not explain all the easy steps. It makes the video too long. Everything else is perfect.

    • @kristakingmath
      @kristakingmath  10 ปีที่แล้ว +6

      Thanks for the feedback. It's always tough to balance... some people like the steps, some don't.

    • @rojasdaniel94
      @rojasdaniel94 10 ปีที่แล้ว +10

      integralCALC Keep the easy steps, I value the longer videos with more information and that's why I come here instead of PatrickJMT or khanacademy! If you want short "tip-clips", watch those guys noob.

    • @moinaction
      @moinaction 10 ปีที่แล้ว +4

      integralCALC The steps is what makes your teaching style stood out from others. Thanks for doing what you do right!

    • @shadowxelnaga
      @shadowxelnaga 10 ปีที่แล้ว

      Daniel Rojas
      you don't know basic algebra?

    • @msokiedokie123
      @msokiedokie123 10 ปีที่แล้ว +1

      The videos are perfect with all the extra steps thanks! Some of us are brilliant at math and forget things! @intergal