Nice Square Root Math Simplification. Math Olympiad | Two methods

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  • Опубліковано 21 лис 2024

КОМЕНТАРІ • 5

  • @abist17
    @abist17 17 днів тому

    a(sqrt(asqrt(a)))=2
    a^2(asqrt(a))=4
    a^6*a=16
    a^7-16=0
    Solution 1: a=2^(4/7)
    Solution 2: on the complex plane, n^7 has to be 16, or in other words, 7θ=2pi
    θ=2pi/7, r=2^(4/7);
    a=2^(4/7)(cos(2pi/7)+isin(2pi/7))

    • @yajurraghavan4193
      @yajurraghavan4193 16 днів тому

      Can't believe they call this an Olympiad question.

    • @yajurraghavan4193
      @yajurraghavan4193 16 днів тому

      Though i didn't consider the complex plane while solving in mind. I just did a^7/4=2 so a=2^4/7 and called it quits

    • @n00bxl71
      @n00bxl71 16 днів тому

      These extra complex solutions do not exist. The only solution is 2^(4/7). You created more solutions when you squared both sides twice. The other replier was correct to only consider a^(7/4)=2 => a=2^(4/7)
      If you try plugging in those complex values, you will not get 2, but rather values that result in 2^4 when raised to the 4th power, e.g. -2,2i, and -2i. You must be careful to consider these cases when raising both sides to a power greater than 1.

    • @yajurraghavan4193
      @yajurraghavan4193 16 днів тому

      @@n00bxl71 i though so, but based on his description, i decided to accept his as the correct answer. I've ignored complex and negative solutions way too many times lol.