A Nice Exponential Equation | Algebra | Math Olympiad Training

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  • Опубликовано: 18 окт 2024

Комментарии • 9

  • @RashmiRay-c1y
    @RashmiRay-c1y 2 месяца назад +1

    Let 5^x=t. Then, the equation becomes t^4-5t^3+6t^2-5t+1=0, which upon dividing both sides bt t^2, yields t^2+1/t^2 -5(t+1/t)+6 = 0 > (t+1/t)^2 -5(t+1/t) + 4 = 0 > t+1/t= 1,4. But t+1/t=1 does not lead to a real x. So, with t+1/4 = 4, t = 2 +/-√3 > x = [ln(2+/-√3)]/ln5.

  • @Shobhamaths
    @Shobhamaths 2 месяца назад +1

    Let 5^x=t; t^4-5t^3+6t^2-5t+1=0;divide with t^2 then
    y=t+1/t;y^2-5y+4=0;x=log(2±√3) /log5👍

  • @kassuskassus6263
    @kassuskassus6263 2 месяца назад +1

    Let 5^x=a and solve a^4-5a^3+6a^2-5a+1=0. Divide both sides by a^2. We get (a^2+1/a^2 -5(a+1/a)+6=0. Let's make another COV, u=a+1/a. Then, we have to solve u^2-5u+4=0. For u=1, the discriminant is negative, and for u=4, we'll get a=2+or-sqrt3. So, x=log(2+or-sqrt3)/log5.

  • @Quest3669
    @Quest3669 2 месяца назад +2

    X= log ( 2+ - √3)/ log 5

  • @RajeshKumar-wu7ox
    @RajeshKumar-wu7ox 2 месяца назад +1

    x=log (2+√3)/log 5 ,log(2-√3)/log5, another solution is comlex not valid.

  • @SidneiMV
    @SidneiMV 2 месяца назад +1

    5ˣ = a
    (a² + 5)/(5a - 1) - 1/(a²) = 1
    a²(a² + 5) - (5a - 1) = a²(5a - 1)
    a²(a² + 5) - (a² + 1)(5a - 1) = 0
    a²(a² + 5) + (a² + 1)(1 - 5a) = 0
    a⁴ + 5a² + a² - 5a³ + 1 - 5a = 0
    a⁴ - 5a³ + 6a² - 5a + 1 = 0
    a² - 5a + 6 - 5/a + 1/a² = 0
    (a² + 1/a²) - 5(a + 1/a) + 6 = 0
    (a + 1/a)² - 5(a + 1/a) + 4 = 0
    a + 1/a = u
    u² - 5u + 4 = 0
    (u - 4)(u - 1) = 0
    u = 4
    a + 1/a = 4
    a² - 4a + 1 = 0
    a = 2 ± √3
    5ˣ= 2 ± √3
    *x = log₅(2 ± √3)*
    u = 1
    a + 1/a = 1
    a² - a + 1 = 0 => complex solution

    • @SidneiMV
      @SidneiMV 2 месяца назад

      x = log₅(2 ± √3)
      verification
      [(2 ± √3)² + 5]/[5(2 ± √3) - 1) - 1/(2 ± √3)² = 1
      (12 ± 4√3)/(9 ± 5√3) - 1/(7 ± 4√3) = 1
      (12 ± 4√3)(7 ± 4√3) - (9 ± 5√3) = (9 ± 5√3)(7 ± 4√3)
      (12 ± 4√3)(7 ± 4√3) = (8 ± 4√3)(9 ± 5√3)
      (3 ± √3)(7 ± 4√3) = (2 ± √3)(9 ± 5√3)
      33 ± 19√3 = 33 ± 19√3

  • @RealQinnMalloryu4
    @RealQinnMalloryu4 2 месяца назад

    10x+{5+5 ➖ }/5{x+x ➖ }{1+1 ➖}(1)^2 = {10x+10 } /5{x^2+2} ➖ 1= 20/5^2x^2 ➖ 1= 20x/{10x^2 ➖ 1}= 20x/9x^2 =2.2x^2 1.1x^2 1x^2 (x ➖ 2x+1). {1+1 ➖}/10x =2/10x 2^1/2^5x 1^1/2^1x 2^1x (x ➖ 2x+1) .

  • @Fjfurufjdfjd
    @Fjfurufjdfjd 2 месяца назад +1

    χ=[log(2+ _ριζα3)]/log5