How to find an explicit formula for a repeating sequence (using sine or cosine)

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  • เผยแพร่เมื่อ 24 พ.ย. 2024

ความคิดเห็น • 15

  • @MC_Transport
    @MC_Transport ปีที่แล้ว +1

    This is like magic

  • @glowmobile596
    @glowmobile596 3 ปีที่แล้ว +3

    Wooo sequences!!!

  • @jadeblades
    @jadeblades 3 ปีที่แล้ว +6

    is there any reason not to do the ceiling function instead of adding 1/2 and multiplying by 2/3? it seems easier to just do ⌈cos(n * 2 * π/3)⌉

    • @gtziavelis
      @gtziavelis 3 ปีที่แล้ว +1

      this reminds me of when he said something about preserving differentiability, and I honestly don't know if that preserves it or not, but he did say that taking the absolute value (a similar thing to floor and ceiling) does not preserve it.

    • @NubPaws
      @NubPaws 3 ปีที่แล้ว +1

      @@gtziavelis Yes it's about differentiability. When working with a series we have tests regarding integration so having a sequence defined as something continuous is important. The ceiling function, and also the absolute value are not differentiable for all x's in their domain.

  • @rogerkearns8094
    @rogerkearns8094 3 ปีที่แล้ว

    Interesting.

  • @rubenverg
    @rubenverg 3 ปีที่แล้ว +6

    isn't the last one clearer if written as √2sin(n*π/2 - π/4)? that way you're also showing that you start at π/4

    • @ZipplyZane
      @ZipplyZane 3 ปีที่แล้ว +1

      Yeah, it makes more sense to simplify, IMO. I expected him to multiply out the inside and fix that, but then he didn't.

    • @madhavsoni2144
      @madhavsoni2144 2 ปีที่แล้ว

      You should include one - sign in front
      Yeah may be there are many ways to write the same thing

  • @quill3731
    @quill3731 3 ปีที่แล้ว

    Nice

  • @claudefleming1011
    @claudefleming1011 ปีที่แล้ว

    is there another formula for this that doesn't involve trigonometric functions? and without modulus operators and without the ceiling and floor operators?

  • @jarikosonen4079
    @jarikosonen4079 3 ปีที่แล้ว

    What if you used unit step function for the 0,0,0,1,...
    Also to make it little more versatile, possible to try make 0,0,1,0,1,1,0,0,1,0,1,1,... or something different between each repeating part.

  • @neverdie0001
    @neverdie0001 2 ปีที่แล้ว

    1) (x%3==0)?1:0 or int(x%3==0)

  • @brenomachado2845
    @brenomachado2845 3 ปีที่แล้ว +3

    Finally first.