A Nice Algebra Problem | Math Olympiad | A Nice Exponential Equation

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  • Опубліковано 8 лис 2024

КОМЕНТАРІ • 6

  • @YAWTon
    @YAWTon 12 годин тому +2

    Hello again...
    The 'usual' transformations lead to the cubic equation x^3-3x-2=0.
    Let f(x)=x^3-3x-2. Then f'(x)=3x^2-3. Therefore f(x) has a local maximum at x=1 and a local minimum at x=-1. Since f(-1)=0 x=-1 is a double root. f(x)/(x+1)^2=x-2, therefore x=2 is a third solution.
    Of course, the two solutions x=-1 and x=2 are immediately obvious...

    • @SALogics
      @SALogics  11 годин тому +1

      Very nice! ❤

  • @ChavoMysterio
    @ChavoMysterio 57 хвилин тому

    [3^(x³)]/(27^x)=9
    [3^(x³)]/(3^3x)=3²
    3^(x³-3x)=3²
    x³-3x=2
    x³-3x-2=0
    x³-x-2x-2=0
    x(x²-1)-2(x+1)=0
    x(x+1)(x-1)-2(x+1)=0
    (x+1)[x(x-1)-2]=0
    (x+1)(x²-x-2)=0
    (x+1)(x+1)(x-2)=0
    x+1=0
    x=-1 ❤❤ multiplicity of 2
    x-2=0
    x=2 ❤

  • @trojanleo123
    @trojanleo123 6 годин тому

    x = { -1 , 2 }

  • @subratabiswas2502
    @subratabiswas2502 10 годин тому

    (3)^x3/3^3x=9 ; i,e 3^(x^3-3x)=3^2 ; i,e x^3-3x=2 ; i,e x^3-3x-2=0 ; x^3+1-3x-3=0 ; i,e (x+1)(x^2-x+1)-3(x+1)=0 ; i,e (x+1)(x^2-x+1-3)=0 ; i,e (x+1)(x^2-x-2)=0 ; i,e (x+1)(x^2-2x+x-2)=0 i,e (x+1)(x-2)(x+1)=0 ; So, x=-1 or x=2 or x=-1.