A Beautiful Problem on Sum of Powers | IMO Longlist

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  • Опубликовано: 12 дек 2024

Комментарии • 38

  • @christopherrice4360
    @christopherrice4360 2 года назад +3

    This is the type of Math video i find worth watching, beautifully done!!

  • @prabhudasmandal6429
    @prabhudasmandal6429 2 года назад +6

    The solution is critical to keep in mind!

  • @bait6652
    @bait6652 2 года назад +2

    nice to see a general solution method!...solved by just repeating Si*S1 (1) xyz (R)& xy+yz+zx (Q) in terms of S2 (2)solved S2 then S5...kinda neat, 2 integer solutions if M unbounded

  • @firdavsrakhmonov2121
    @firdavsrakhmonov2121 2 года назад +1

    Nice problem and of course nice solution! Would be great if you can upload more combinatorial problems.

  • @stephenlpitts
    @stephenlpitts 2 года назад +1

    If the last equation had been x^4 + y^4 + z^4 = 33, the solution would have been so much easier. Simple trial and error reveals x=y=2 and z=-1 satisfies all of the stipulations. Then the answer is simply 32 + 32 -1 = 63. Interesting how such a small change on the one equation makes such a difference.

  • @nirmankhan2134
    @nirmankhan2134 2 года назад +7

    That was a nice one. I solved it. I used elementary symmetric functions to find the value of symmetric functions of degree 1,2,3 of three variables then put them in vieta's formula to find x,y and z. Then put them in the S5. 😇

    • @mustafizrahman2822
      @mustafizrahman2822 2 года назад

      Einstein is always Einstein. By the way, you haven't taken Ifter meals from our house. I think you like our hospitability and food. We are now sad about your conduct because you have not taken Iftari foods.

  • @Szynkaa
    @Szynkaa 2 года назад +2

    i solved it totally different (and in my opinion easier) way. I directly solved this system of equations and got solutions (x,y,z)=(1,sqrt(2)+1,1-sqrt(2)) and permutations. Then i just find x^5+y^5+z^5 easily

    • @Szynkaa
      @Szynkaa 2 года назад +1

      Futhermore, my method proves that without condition x^2+y^2+z^2

    • @pierpaoloarmilio5513
      @pierpaoloarmilio5513 2 года назад

      I think that I’ve solved the problem in the same your way. I’ve just used two algebraic tricks: x+y = 3-z, x^3 + y^3 = (x+ y)(x^2 -xy + y^2) = 15 - z^3 and (x^2 + y^2)^2 = 35 - z^4 +2(xy)^2. After these passages solve the new system and you obtain an 6th degree equation in z but really easy to solve using Ruffini for example or some decomposition, you find z = 1 and so substitute this in the previous equations and you get a second degree equation in xy solving that equation you obtain xy =-1 or xy = 15 and always by substitution you’ve done (i.e. your solutions). In this way, more computational, the system can be solved also by one who doesn't know much “advanced” math, in the spirit of IMO (tested for the high school guys).

    • @granchiopodista8660
      @granchiopodista8660 2 года назад

      The two method are the same in reality but they seems different

  • @raunakmukherjee8029
    @raunakmukherjee8029 2 года назад

    gained a new appreciation for vieta's formula

  • @firdavsrakhmonov2121
    @firdavsrakhmonov2121 2 года назад

    I was wondering can you upload solutions to IMO 1969 Problems 1 and 6. Thank you!

  • @empajerek4193
    @empajerek4193 2 года назад +1

    so cool!

  • @armacham
    @armacham 2 года назад +3

    The image at the start of the video should have the entire problem

  • @beautifulworld6163
    @beautifulworld6163 2 года назад

    I thought you are going to solving for x,y,z. Is this possible in this problem?

    • @granchiopodista8660
      @granchiopodista8660 2 года назад

      Yes, you can simplify the system in this two equation where the solutions are x, y and z:
      λ³−3λ²+λ+1=0
      and
      λ³−3λ−λ+7=0
      The first one is easy to solve by factoring the second one you can prove that the solutions aren’t all real (or you can see that S₂>0)
      But this is his method with a more complicated final (if you want to find x⁵+y⁵+z⁵)

  • @daoudandiaye4636
    @daoudandiaye4636 2 года назад

    Class!

  • @raunakmukherjee8029
    @raunakmukherjee8029 2 года назад

    👍

  • @iceblaze8180
    @iceblaze8180 2 года назад

    I Solved With Girard-Newton Identity,It's Take 5 Minutes

    • @brinzanalexandru2150
      @brinzanalexandru2150 2 года назад

      How did you get the value of x²+y²+z² I started solving by this method also and I need the value of only x²+y²+z²

    • @iceblaze8180
      @iceblaze8180 2 года назад

      @@brinzanalexandru2150 After Reach X^4 + Y^4 + Z^4,You Just Solve For e2,p2,And e3

    • @brinzanalexandru2150
      @brinzanalexandru2150 2 года назад

      @@iceblaze8180 can u explain it further

  • @tianqilong8366
    @tianqilong8366 2 года назад

    😍😍😍😍🔥🔥🔥🔥

    • @mustafizrahman2822
      @mustafizrahman2822 2 года назад

      Where are you from?

    • @nirmankhan2134
      @nirmankhan2134 2 года назад

      @@mustafizrahman2822 hello

    • @tianqilong8366
      @tianqilong8366 2 года назад

      @@mustafizrahman2822 nice to meet you. I am from ghe Earth?

    • @mustafizrahman2822
      @mustafizrahman2822 2 года назад

      @@tianqilong8366 Ghe earth! What is this? Are you from China?

    • @mustafizrahman2822
      @mustafizrahman2822 2 года назад

      @@nirmankhan2134 Einstein is always Einstein. By the way, you haven't taken Ifter meals from our house. I think you like our hospitability and food. We are now sad about your conduct because you have not taken Iftari foods.

  • @ShefsofProblemSolving
    @ShefsofProblemSolving 2 года назад

    Hi letsthinkcritically! I send you an email about Shef's Scholars which could be of interest to your viewer who are competing in math competitions !