Can you solve this ?? | iota maths problem | Oxford entrance exam question

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  • เผยแพร่เมื่อ 1 ธ.ค. 2024

ความคิดเห็น • 34

  • @stevenbeddegenoodts4871
    @stevenbeddegenoodts4871 22 ชั่วโมงที่ผ่านมา +4

    it's wrong, solution is +/- sqrt2 and +/- i*sqrt2. 4 solutions for combining two +/- options. and also it much easier in polar form "-1=e^(i*pi)" so sqrt(i) =+/- e^(i*pi/4)

    • @sputnikv1081
      @sputnikv1081 20 ชั่วโมงที่ผ่านมา +2

      Totally agreed ^

    • @AndreTewen
      @AndreTewen 19 ชั่วโมงที่ผ่านมา +1

      Exact.
      sqrt(z) if we work with imaginary numbers, owns two values (|z|, arg(z)/2) and
      (|z|, arg(z)/2 + pi).

    • @troyvanleuken1304
      @troyvanleuken1304 18 ชั่วโมงที่ผ่านมา

      @@AndreTewen a = z^2 had 2 solutions, +/- sqrt(a) but z = sqrt(a) only has 1 solution; sqrt(a) because the formula already sais to take the positive only and not the negative. so since the formula is sqrt(i) + sqrt(-i) the only right solution is sqrt(2). It is not possible for this formula to have multiple solutions. See wolframalpha if you dont believe me.
      how to work out:
      1) i = e^i*pi/2 == > sqrt(i) = e^i*pi/4 and sqrt(-i) = e^-i*pi/4
      2) since e^i*x = cos(x) + i * sin(x):
      ==> sqrt(i) + sqrt(-i) = e^i*pi/4 + e^-i*pi/4 = cos(pi/4) + i*sin(pi/4) + cos(-pi/4) + i* sin(-pi/4) = 2*cos(pi/4) = 2* sqrt(2)/2 = sqrt(2)

    • @AndreTewen
      @AndreTewen 18 ชั่วโมงที่ผ่านมา +1

      @@troyvanleuken1304
      |C does not have order relationship,
      and "sqrt" is not à function :
      we can write sqrt(z) = (sqrt(|z|), arg(z)/2 + k.pi) with k = 0 or 1.
      So the raised question can be translated into 4 equations following
      the k values. with the 4 solutions :
      k=0, k=0. ==> sqrt(2).i
      k=0, k=1 ==> sqrt(2)
      k=1, k=0. ==> -sqrt(2)
      k=1, k=1 ==> -sqrt(2).i

    • @AsadInternationalAcademy
      @AsadInternationalAcademy  12 ชั่วโมงที่ผ่านมา

      why/

  • @arekkrolak6320
    @arekkrolak6320 23 ชั่วโมงที่ผ่านมา

    Cool trick! Bonus points for not losing multiple solutions of sceruto!

    • @AsadInternationalAcademy
      @AsadInternationalAcademy  22 ชั่วโมงที่ผ่านมา

      Glad you liked it!

    • @AsadInternationalAcademy
      @AsadInternationalAcademy  22 ชั่วโมงที่ผ่านมา

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  • @nikolayplatnov5148
    @nikolayplatnov5148 21 ชั่วโมงที่ผ่านมา

    Seems, more convenient to resolve in exponential forn, whe the equation is sgrt (exp (i×pi/2+ 2pi N))+ sgrt (exp(i3pi/2+2pi N)) etc...

    • @AsadInternationalAcademy
      @AsadInternationalAcademy  12 ชั่วโมงที่ผ่านมา

      thanks

    • @AsadInternationalAcademy
      @AsadInternationalAcademy  12 ชั่วโมงที่ผ่านมา

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  • @michaeldoerr5810
    @michaeldoerr5810 2 วันที่ผ่านมา

    The answer is +/- sqrt(2). This was surprisingly easy to do!!! I shall use that for practice!!!

  • @leonardosuriano8260
    @leonardosuriano8260 15 ชั่วโมงที่ผ่านมา +1

    I have an easy easy solution: √i+√-i=X --> (√i+√-i)^2=X^2 --> (i+2-i) = X^2 --> X= ±√2. EASY.

    • @AsadInternationalAcademy
      @AsadInternationalAcademy  12 ชั่วโมงที่ผ่านมา

      wonderful! thanks

    • @AsadInternationalAcademy
      @AsadInternationalAcademy  12 ชั่วโมงที่ผ่านมา

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  • @d95mback
    @d95mback 21 ชั่วโมงที่ผ่านมา

    You can't take ±1/√2 as a common factor, since it stands for _either_ plus or minus, and not necessarily at the same time for both terms.

    • @AsadInternationalAcademy
      @AsadInternationalAcademy  12 ชั่วโมงที่ผ่านมา

      okay but why?

    • @AsadInternationalAcademy
      @AsadInternationalAcademy  12 ชั่วโมงที่ผ่านมา

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  • @carfer
    @carfer 17 ชั่วโมงที่ผ่านมา

    Lacks the solution: +/-Sqr(2)*i
    Sqr(i) = (1/Sqr(2))*(1+i) and Sqr(i) = (-1/Sqr(2))*(1+i)
    And
    Sqr(-i) = (1/Sqr(2))*(1-i) and Sqr(-i) = (-1/Sqr(2))*(1-i)
    So, it's necessary to sum all the possibilities, and it supposes four solutions.

    • @carfer
      @carfer 16 ชั่วโมงที่ผ่านมา

      If we take as a criterion that the root of a complex number is the complex number with the smallest positive angle in the complex plane, something similar to the fact that the root of a real number is always positive, then there would be a unique solution: Sqr(2)*i
      But, I'm not sure if this could be a good criterion.

    • @JoeTaxpayer
      @JoeTaxpayer 13 ชั่วโมงที่ผ่านมา

      I solved to get i sqrt(2).
      And multiple AI confirmed my answer. FWIW, I used DeMoivre’s formula to solve.

    • @AsadInternationalAcademy
      @AsadInternationalAcademy  12 ชั่วโมงที่ผ่านมา

      thanks

    • @AsadInternationalAcademy
      @AsadInternationalAcademy  12 ชั่วโมงที่ผ่านมา

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    • @AsadInternationalAcademy
      @AsadInternationalAcademy  12 ชั่วโมงที่ผ่านมา

      ok

  • @amirghobadzadeh6546
    @amirghobadzadeh6546 16 ชั่วโมงที่ผ่านมา

    your answer is wrong!!!

    • @AsadInternationalAcademy
      @AsadInternationalAcademy  12 ชั่วโมงที่ผ่านมา

      why?

    • @AsadInternationalAcademy
      @AsadInternationalAcademy  12 ชั่วโมงที่ผ่านมา

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