China | Can you solve this? | Math Olympiad

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  • Опубликовано: 5 ноя 2024

Комментарии • 120

  • @Alamaths
    @Alamaths  Месяц назад +5

    Hello My Dear Family😍😍😍
    I hope you all are well 🤗🤗🤗
    If you like this video about
    How to solve this math problem
    Please like and subscribe to my channel as it helps me a lot,🙏🙏🙏🙏
    ❤❤🎉🎉

  • @key_board_x
    @key_board_x Месяц назад +22

    √2 + √x = 2 → where: x ≥ 0
    √x = 2 - √2
    (√x)² = (2 - √2)²
    x = 4 - 4√2 + 2
    x = 6 - 4√2

    • @Alamaths
      @Alamaths  Месяц назад +1

      Wow 😮, thank you so much for the comments 👍❤ .
      Where are you watching from 💖?

    • @key_board_x
      @key_board_x Месяц назад +1

      @@Alamaths I'm watching from France

    • @Alamaths
      @Alamaths  Месяц назад +2

      @@key_board_x Wow, thanks 😊

  • @sy8146
    @sy8146 Месяц назад +17

    Thank you for explaining. The solution is (only) x=6-4√2 . [ x=6+4√2 must be rejected. ] Please check.

    • @Alamaths
      @Alamaths  Месяц назад +4

      Great 👍. It is true. Thanks for the comments. Are you a maths teacher 💖?

    • @tapiola61
      @tapiola61 Месяц назад +2

      I calculated under 15 seconds, should have done it head but not today. From Finland.

    • @toninhorosa4849
      @toninhorosa4849 Месяц назад +4

      Dear teacher I solved a little different:
      √2 + √x = 2
      √x = 2 - √2
      (√x)^2 = (2 -√2)^2
      x = 4 - 4√2 + 2
      x = 6 - 4√2
      This is de only solution.
      Thanks

    • @sy8146
      @sy8146 Месяц назад +2

      @@Alamaths In the past, I was a math teacher in Japan.

    • @nguyenvietxuan7843
      @nguyenvietxuan7843 23 дня назад +1

      ​@@Alamathsx = 6+4√2 >2 không thỏa mãn đầu bài. Tác giả tự làm phức tạp bài toán √2+√x=2, -> √x= 2-√2,-> x= (2-√2)(2-√2)= 4-4√2+2= 6-4√2.

  • @habeebalbarghothy6320
    @habeebalbarghothy6320 Месяц назад +10

    x^0.5 = 2 - 2^0.5
    Square both sides
    x = 4 - 4.2^0.5 + 2
    x = 6 - 4.2^0.5

  • @HansTelerud
    @HansTelerud Месяц назад +2

    I agree The solution is only x=6-4√2 . I had a great deal work to verify this solution in the original equation in an exactly way.

    • @Alamaths
      @Alamaths  Месяц назад +1

      Great 👍. Thanks for the comments.
      Where are you watching from 💖?

  • @jamesharmon4994
    @jamesharmon4994 Месяц назад +4

    The first step I would make is moving sqrt(2) to the right. This puts variables on one side, constants on the other. Then square both sides resulting in:
    sqrt(x)^2 = (2 - sqrt(2))^2.
    x = 2^2 - 2(2*sqrt(2)) + sqrt(2)^2.
    All that's left is collecting terms and simplifying.❤

    • @Alamaths
      @Alamaths  Месяц назад +1

      Yes. Thanks for the comments 👍
      Where are you watching from 💖?

  • @toninhorosa4849
    @toninhorosa4849 Месяц назад +3

    I solved a little different:
    √2 + √x = 2
    √x = 2 - √2
    (√x)^2 = (2 - √2)^2
    x = 4 - 4√2 + 2
    x = 6 - 4√2
    There are only this solution for "x" in this problem.

    • @Alamaths
      @Alamaths  Месяц назад +2

      Yes. Thanks for the comments 👍.
      Where are you watching from 💖?

    • @toninhorosa4849
      @toninhorosa4849 Месяц назад +1

      @@Alamaths
      I am watching from São Paulo - Brazil.🇧🇷🇧🇷

    • @Alamaths
      @Alamaths  Месяц назад +1

      @toninhorosa4849 wow, thanks for the comments 👍. Where are you watching from 💖?

  • @prabirsarkar504
    @prabirsarkar504 Месяц назад +1

    Through this math you are trying to express yourself that what a scholar

    • @Alamaths
      @Alamaths  Месяц назад +1

      Great. Thanks for the comments 👍
      Are you a professor of maths 💖?

  • @nafisatsulaiman-cd2xm
    @nafisatsulaiman-cd2xm Месяц назад +1

    Thanks so much sirr 😊

    • @Alamaths
      @Alamaths  Месяц назад +1

      ❤❤ thanks for the comments

  • @jmlfa
    @jmlfa Месяц назад +3

    sqrt(x) = 2 - sqrt(2) >> x = 0.343 (elementary school)

    • @Alamaths
      @Alamaths  Месяц назад +1

      Great 👍. Thanks for the comments
      Are you a maths teacher 💖?

  • @joshuamoses9274
    @joshuamoses9274 Месяц назад +1

    Good one there! 😊

    • @Alamaths
      @Alamaths  Месяц назад +1

      Yes. Thanks for the comments 👍
      Where are you watching from 💖?

  • @devapriyaguharoy7745
    @devapriyaguharoy7745 Месяц назад +2

    Impressed the way you present math to beginners. Great job 👏
    Speaking from India.

    • @Alamaths
      @Alamaths  Месяц назад +1

      Wow, thank you!

  • @akr749
    @akr749 21 день назад +3

    Too many unnecessary steps. Sol. 6+4√2 is incorrect.
    √2+√x=2
    √x=2-√2
    x=(2-√2)^2
    x=4-2*2√2+2
    x=6-4√2

    • @Alamaths
      @Alamaths  21 день назад

      Thanks for the comments 👍
      Are you a maths teacher 💖?

    • @akr749
      @akr749 21 день назад

      @@Alamaths no, I am not. I am an engineer.

  • @lakshmikutty2255
    @lakshmikutty2255 Месяц назад +1

    √x+√2=2
    X=(2-√2) ^ 2= 4+2-2×2√2
    =6-4√2=2(3-2√2)

    • @Alamaths
      @Alamaths  Месяц назад +1

      Yes. Thanks for the comments 👍
      Are you a maths teacher 💖?

  • @KhinMaungSan-qc9uv
    @KhinMaungSan-qc9uv Месяц назад +1

    √x=2--√2>>>square both sides.etc.

    • @Alamaths
      @Alamaths  Месяц назад +1

      Yes. Thanks for the comments 👍
      Where are you watching from 💖?

  • @gagik9401
    @gagik9401 Месяц назад +1

    if the final answer is an irrational number, there is no point in doing the transformations. You can simply calculate in the first calculus by taking 2 from the radical

    • @Alamaths
      @Alamaths  Месяц назад +1

      No. Thanks for the comments 👍
      Where are you watching from 💖?

  • @seedseed7801
    @seedseed7801 10 дней назад +1

    incorect

    • @Alamaths
      @Alamaths  10 дней назад +1

      Great 👍. Thanks for the comments
      Are you a maths teacher 💖?

    • @seedseed7801
      @seedseed7801 9 дней назад +1

      @@Alamaths Here's the translation:
      I’m learning a lot from watching your videos. I’m an ordinary working professional in my 50s living in Korea, and watching these videos brings back memories of my school days. I couldn’t leave a polite comment because I’m not very confident in English, but your videos have been a great help, and I enjoy watching them.

    • @Alamaths
      @Alamaths  9 дней назад +1

      @@seedseed7801 thanks 😊

  • @thuyngoc2542
    @thuyngoc2542 Месяц назад +1

    Thầy hãy thử với nghiệm x1 nhé

    • @Alamaths
      @Alamaths  Месяц назад +1

      Ok... thanks for the reply 👍. Where are you watching from 💖?

  • @evbdevy352
    @evbdevy352 Месяц назад +1

    It is rather long way.

    • @Alamaths
      @Alamaths  Месяц назад +1

      Okay 👍. Thanks for the comments
      Are you a professor of maths 💖?

    • @evbdevy352
      @evbdevy352 Месяц назад

      @@Alamaths No,I am not,only a teacher

  • @subratabiswas2502
    @subratabiswas2502 Месяц назад +1

    √x=2-√2 ; i,e x=4+2-4√2 ; x=6-4√2 2nd method. √2+√x=2 ; i,e 2+x+2√2x=4 ; i,e x+2√2x=2 ; 2√2x=2-x ; 8x=x^2+4-4x ; x^2-12x+4=0 ; x= (12+√144-16)/2 or x= (12-√144-16)/2 ; i,e x= (12+8√2)/2 ; x= 6+4√2 or x= 6-4√2

    • @Alamaths
      @Alamaths  Месяц назад +1

      Wow, thanks for the comments 👍
      Are you a professor of maths 💖?

  • @1zaj34
    @1zaj34 Месяц назад +5

    Sorry to bother, but this is overly complicated (and false). By squaring an equation you can create extraneous solutions (you did! x=6+4√2 is false).
    Much easier would be to just substract √2 from both sides and only then to square the equation. This gives directly x=6-4√2 which is the only solution.
    The reason behind this is the "dichotomy" of squares and roots:
    √4 has only one(!) solution: "2".
    But x²=4 has two solutions: +√4 = +1 * 2 = "2" and -√4 = -1 * 2 = "-2"

    • @Alamaths
      @Alamaths  Месяц назад +1

      Great 👍. Thanks for the comments.
      Are you a professor of maths 💖?

    • @1zaj34
      @1zaj34 Месяц назад +2

      @@Alamaths No, I am "just" an engineer.

    • @Alamaths
      @Alamaths  Месяц назад +1

      @@1zaj34 okay 👍. Thanks for the reply.

    • @petersmith264
      @petersmith264 Месяц назад +1

      Yes. I noticed this too. Watch out for extraneous roots. And yes, there is a much easier way to solve.

  • @mohamedkhatimi8938
    @mohamedkhatimi8938 Месяц назад +1

    in: √(2x) = (2-x)/2
    (2-x)/2 must be ⩾0
    So: 2 ⩾ x
    So: x ≤ 2
    But: 6 + 4√2 ⩾ 2
    So: 6 + 4√2 is not solution
    S = { 6 - 4√2 }
    Because: (6 - 4√2) ≤ 2

    • @Alamaths
      @Alamaths  Месяц назад +1

      Great 👍. Thanks for the comments
      Where are you watching from 💖?

    • @mohamedkhatimi8938
      @mohamedkhatimi8938 Месяц назад +1

      @@Alamaths
      From Morocco

    • @Alamaths
      @Alamaths  Месяц назад

      @@mohamedkhatimi8938 Great 👍. How is everything over there?

    • @mohamedkhatimi8938
      @mohamedkhatimi8938 Месяц назад

      ​@@Alamaths
      Very nice

  • @hunghuynh4846
    @hunghuynh4846 Месяц назад +1

    √x = 2 - √2. X = (2 -√2)......

    • @Alamaths
      @Alamaths  Месяц назад +1

      Thanks for the comments. Are you a maths teacher 💖?

  • @Nazimİsmayılov-e9u
    @Nazimİsmayılov-e9u Месяц назад +1

    1.bərabərliyin hər iki tərəfini 2-yə bölüb qüvvətə yüksəltdikdən sonra 4-ə vurmaq nəyə lazım idi?Elə birbaşa qüvvətə yüksəltsə idiniz eyni nəticə alınacaqdı.
    2. X^2-12X+4=0 şevrilmiş kvadrat tənlik olduğundan onun köklərini
    X=-P/2+-*(P/2)^2 -q kimi həll etsə idiniz daha əlverişli olmazdımı?
    Təşəkkürlər.

    • @Alamaths
      @Alamaths  Месяц назад +1

      Yes. Thanks for the comments 👍
      Where are you watching from 💖?

    • @БайрамовАрзуман
      @БайрамовАрзуман Месяц назад

      Məlum bir tərəfə məhcul digər tərəfə etməklə alınan ifadə sqrt(x)=2-sqrt(2)

  • @purushothamanm.k778
    @purushothamanm.k778 Месяц назад +1

    6-4 root 2 is the onlycorrect answer

    • @Alamaths
      @Alamaths  Месяц назад +1

      Great 👍. Thanks for the comments.
      Where are you watching from 💖?

  • @martinzavalaleon8856
    @martinzavalaleon8856 Месяц назад +1

    Siempre cuando obtengas un número al cuadrado, como lo haces, pierdes información crucial sobre el número que elevas al cuadrado. Esa información es la positividad o negatividad del número.
    Para ser precisos, en el momento que elevas al cuadrado a 2 - x, estás permitiendo que 2 - x sea negativo y esto no puede ser.
    Es por eso que obtienes dos soluciones a la ecuacion cuadrática, que no tienen por qué ser soluciones de la ecuación original. De hecho desde la ecuación original tenemos que solo habrá una solución obtenida como alguien te comentó antes.
    x = sqrt(2 - sqrt(2)).

    • @Alamaths
      @Alamaths  Месяц назад +1

      Noted. Thanks for the comments 👍
      Are you a professor of maths 💖 🤔?

    • @martinzavalaleon8856
      @martinzavalaleon8856 Месяц назад

      @@Alamaths Yes, I am

  • @yanssala2214
    @yanssala2214 Месяц назад +1

    Redondeado
    x = 0,343...es irracional

    • @Alamaths
      @Alamaths  Месяц назад +1

      Yes. Thanks for the comments 👍.
      Are you a maths graduate 💖?

  • @walterwen2975
    @walterwen2975 Месяц назад +1

    Math Olympiad: √2 + √x = 2; x =?
    2 > √2 > 1 > √x > 0; √x = 2 - √2, x = (√x)² = (2 - √2)² = 2² - 4√2 + (√2)² = 6 - 4√2
    Answer check:
    x = 6 - 4√2 = (2 - √2)²; √x = 2 - √2, √2 + √x = 2; Confirmed
    Final answer:
    x = 6 - 4√2
    Note:
    If: x = 6 + 4√2 > 9, √2 + √x > 3; x ≠ 6 + 4√2

    • @Alamaths
      @Alamaths  Месяц назад +1

      Great 👍. Thanks for the comments . Where are you watching from 💖?

    • @walterwen2975
      @walterwen2975 Месяц назад +1

      @@Alamaths USA

    • @Alamaths
      @Alamaths  Месяц назад +1

      @@walterwen2975 Wow, thanks.
      How is everything over there?

  • @عليالنجفي-ض8ذ
    @عليالنجفي-ض8ذ 29 дней назад

    عندما نعوض قيمة xالناتجه في المعادله نجد ان الطرف الأيسر لا يساوي الطرف الأيمن اذن الحل خطاء

    • @Alamaths
      @Alamaths  28 дней назад

      Great. Thanks for the comments 👍
      Are you a maths teacher 💖?

  • @edwinpittomvils2570
    @edwinpittomvils2570 Месяц назад +1

    This is easy math, not Olympiad level

    • @Alamaths
      @Alamaths  Месяц назад +1

      Okay. Thanks for the comments 👍. Where are you watching from 💖?

  • @conarddranoc7618
    @conarddranoc7618 Месяц назад +3

    not good! at 3:00 to take square on both side, x must be >=0 and x must be

    • @Alamaths
      @Alamaths  Месяц назад +1

      Great 👍. Thanks for the comments
      Where are you watching from 💖?

    • @conarddranoc7618
      @conarddranoc7618 Месяц назад +1

      @@Alamaths from algeria👍

    • @Alamaths
      @Alamaths  Месяц назад +1

      @@conarddranoc7618 Great 👍. Thanks for the comments.

  • @ΔΗΜΗΤΡΗΣΑΓΑΤΣΑΣ
    @ΔΗΜΗΤΡΗΣΑΓΑΤΣΑΣ Месяц назад +2

    dekti mono 6-4.i,41....

    • @Alamaths
      @Alamaths  Месяц назад +1

      Yes. Thanks for the comments 👍
      Where are you watching from 💖?

    • @ΔΗΜΗΤΡΗΣΑΓΑΤΣΑΣ
      @ΔΗΜΗΤΡΗΣΑΓΑΤΣΑΣ Месяц назад +1

      @@Alamaths Greece..

    • @Alamaths
      @Alamaths  Месяц назад +1

      @@ΔΗΜΗΤΡΗΣΑΓΑΤΣΑΣ Wow, thanks 😊

  • @محمدالنجار-و2ف
    @محمدالنجار-و2ف Месяц назад +1

    + ve never right

  • @stephandobush7935
    @stephandobush7935 Месяц назад +1

    6+4sqrt(2)=12. ... It is not the solution!!!!

    • @Alamaths
      @Alamaths  Месяц назад +1

      Great 👍. Thanks for the comments
      How is everything over there?

  • @nufailanoon
    @nufailanoon Месяц назад +1

    You square both sides so you end up with
    2 + x = 2^2
    X = 4 - 2
    X = 2

    • @Alamaths
      @Alamaths  Месяц назад +1

      Great 👍. Thanks for the comments
      Where are you watching from 💖?

    • @1zaj34
      @1zaj34 Месяц назад

      Huh, this is a joke, right?

    • @nufailanoon
      @nufailanoon Месяц назад

      @@1zaj34 why

    • @1zaj34
      @1zaj34 Месяц назад

      @@nufailanoon Because, if you square "√2 + √x" the anser is not(!) "2 + x" but "2 + 2√2√x + x". Binomial theorem: (a + b)^2 = a^2 + 2ab + b^2

    • @nufailanoon
      @nufailanoon Месяц назад

      @@1zaj34 Oh yea
      (a + b) ^2 is a^2 +2ab + b^2
      But I thought the square will cancel the square roots?

  • @alexandertia2666
    @alexandertia2666 Месяц назад +2

    Laughable way of solving...its like spaghetti...simplify first by putting x on 1 side then constants on the other side...see comments above

    • @Alamaths
      @Alamaths  Месяц назад +1

      Yeah. Thanks for the comments 👍
      Are you a maths teacher 💖?

  • @mirkosoft1000
    @mirkosoft1000 14 дней назад +2

    This is so wrong!

  • @imamkhambali1212
    @imamkhambali1212 Месяц назад +1

    Too worse time

    • @Alamaths
      @Alamaths  Месяц назад +1

      Noted. Thanks for the comments 👍.
      Where are you watching from 💖?

  • @БайрамовАрзуман
    @БайрамовАрзуман Месяц назад +1

    !/x=2-!/2
    X=(2-!/2)²=4-4!/2+2=6-4!/2

  • @anatolijpachomenko8280
    @anatolijpachomenko8280 24 дня назад +1

    Совершенно нерациональный способ решения. И результат ошибочный: два корня вместо одного. Если автор видео запутался в решении такой примитивной задачи, которая была рассмотрена, то ему должно быть очень стыдно и лучше впредь не пытаться заниматься математикой.

    • @Alamaths
      @Alamaths  24 дня назад +1

      Great 👍. Thanks for the comments.
      Are you a maths teacher 💖?

  • @arturovera1721
    @arturovera1721 Месяц назад +1

    jajajaj most of people speak English.

    • @Alamaths
      @Alamaths  Месяц назад +1

      Great 👍. Thanks for the comments
      Where are you watching from 💖?

  • @telemans107
    @telemans107 27 дней назад +1

    Stay away from mathematics .you made it too complicated .

    • @Alamaths
      @Alamaths  27 дней назад +1

      OK 👍. Thanks for the comments
      Where are you watching from 💖?

  • @sie_khoentjoeng4886
    @sie_khoentjoeng4886 Месяц назад +1

    √2 + √X = 2
    √X = 2 - √2
    (√X)^2 = (2 - √2)^2
    X = (2 - √2) (2 - √2)
    X = 4 - 2√2 - 2√2 + 2
    X = 6 - 4√2
    Let's check!!
    X = 6 - 4√2 = 0.34314..
    √2 + √0.34314.. = 2
    FYI: For X = 6 + 4√2
    X = 6 + 4√2 = 11.65685..
    √2 + √11.65685.. = 4.8284..

    • @Alamaths
      @Alamaths  Месяц назад +1

      Great 👍. Thanks for the comments.
      Are you a professor of maths 💖?

    • @ТамараМошникова
      @ТамараМошникова Месяц назад

      Ведь элементарный пример, зачем усложнять простейшее, не пойму!

  • @satyamshivamsundaram5512
    @satyamshivamsundaram5512 Месяц назад +1

    It takes 1 minute.Wasting 8 minutes is funny and foolishness.
    2nd step..square root of x=2-root 2
    Squaring both sides
    x=2-root2 whole square.
    = 4+2-4root 2.
    = 6-4root2.
    Mind that VIEWERS are not L.K.G. students.
    By seeing your time wasting version ,
    I remeber one saying,
    Digging a MOUNTAIN and getting a RAT.😂😂😂😂😂😂😂😂😂😂😂😂😂.
    It clearly means that basically you do not know
    simple methods and time saving skills.If you have perfect and thorough knowledge, by adopting
    simple methods and easy
    tricks one fourth of time is sufficient. Or else you can as well keep HEADING ' LESSON FOR 6th CLASS KIDS"😂😂😂😂😂

    • @Alamaths
      @Alamaths  Месяц назад +1

      Great, Prof . Thanks for the comments 👍
      Where are you watching from 💖?