France | A Nice Math Olympiad Algebra Problem

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  • Опубликовано: 18 ноя 2024

Комментарии • 29

  • @ajitandyokothakur7191
    @ajitandyokothakur7191 6 месяцев назад

    Very elegantly done such that a retired mathematics professor like myself cam appreciate. Dr. Ajit Thakur (USA).

  • @kwa6022
    @kwa6022 7 месяцев назад +2

    You should not stop if y is complex. the 12th power of y may not be complex.

  • @is7728
    @is7728 7 месяцев назад +7

    Brilliant

  • @MathSync
    @MathSync 7 месяцев назад +2

    Math is My ❤

  • @Lemda_gtr
    @Lemda_gtr 3 месяца назад

    Your font is very cool 👌

  • @mennoydema5222
    @mennoydema5222 7 месяцев назад

    Nice video. I'm not sure if people would immediately see that 12=2^3+2^2. And putting 2^10 in there is totally random, people would have to put that in a calculator just as much as they would 2^12 to come to the number of 4096.

  • @irinabaigozina8551
    @irinabaigozina8551 6 месяцев назад

    Very nice, thank you!

  • @glennmann634
    @glennmann634 7 месяцев назад +2

    Beautiful solution

  • @goendgishuya5313
    @goendgishuya5313 6 месяцев назад

    Can you explain why you get -8 & -4

  • @Misha-g3b
    @Misha-g3b 6 месяцев назад

    Автор решает уравн. y³+y²-12=0 ycложнённо: ведь видно, что y=2 и 2 - единственный полож. корень.

  • @Vadimdim1967
    @Vadimdim1967 6 месяцев назад

    Браво 👍

  • @АлександрПавлов-з7р
    @АлександрПавлов-з7р 7 месяцев назад +4

    4096. Перебором...

  • @Misha-g3b
    @Misha-g3b 6 месяцев назад

    4096.

  • @Mal1234567
    @Mal1234567 6 месяцев назад

    now solve 4th root of x + 6th root of x = 13.

    • @oahuhawaii2141
      @oahuhawaii2141 2 месяца назад +1

      That's easy, since you specified x = 13.
      The 4th root of x is ⁴√13.
      The 6th root of x is ⁶√13.
      Thus, the sum is ⁴√13 + ⁶√13.

  • @ST-sd8un
    @ST-sd8un 7 месяцев назад

    Excelente !

  • @vbphysiologyexp682
    @vbphysiologyexp682 7 месяцев назад

    х=4096

  • @DC-zi6se
    @DC-zi6se 7 месяцев назад +1

    These so called Olympiad problems are surprisingly easy

    • @SalmonForYourLuck
      @SalmonForYourLuck 6 месяцев назад

      ofc it is easy when you see the answer but when you have to do all of this in a limited time, the real challenge begins.

  • @himadrikhanra7463
    @himadrikhanra7463 6 месяцев назад

    Sorry 2^12..?

  • @مهدیخواجه-و3ت
    @مهدیخواجه-و3ت 7 месяцев назад

    سوال قشنگی بود ولی بهتر نبود جای اون همه کار ریشه درجه سه رو حدس میزدی و با تقسیم حل میکردی

  • @oahuhawaii2141
    @oahuhawaii2141 2 месяца назад

    I'll guess that x = 2¹² = 4096 :
    ⁴√2¹² + ⁶√2¹² = 2³ + 2² = 8 + 4 = 12
    Let's formally find all solutions:
    ⁴√x + ⁶√x = 12
    ¹²√x³ + ¹²√x² = 12
    This is a cubic equation in y = ¹²√x :
    y³ + y² = 12
    Let's do a quick check with factorization:
    y²*(y + 1) = 2²*3
    It's clear that y = 2 is a solution. We know (y - 2) is a factor below:
    y³ + y² - 12 = 0
    (y - 2)*(y² + 3*y + 6) = 0
    y = 2, (-3 ± i*√15)/2
    x = y¹² = 2¹², (-3 ± i*√15)¹²/2¹²
    Let's manually calculate this as (((y²)*y)²)² :
    y¹ = 2, (-3 ± i*√15)/2
    y² = 4, -3*(1 ± i*√15)/2
    y³ = 8, 3*(9 ± i*√15)/2
    y⁶ = 64, 27*(11 ± i*3*√15)/2
    y¹² = 4096, 729*(-7 ± i*33*√15)/2
    Thus:
    x = 4096, 729*(-7 ± i*33*√15)/2
    Let's add y² and y³ from the lines listed above:
    y² = 4, -3*(1 ± i*√15)/2
    y³ = 8, 3*(9 ± i*√15)/2
    y²+y³ = 12, 12 ± 0
    This checks out.
    BTW: You said "one hundred twenty four" for 1024, and "four hundred ninety six" for 4096. You should've said "thousand" instead of "hundred".