Factoring a Cubic Polynomial in Two Ways

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  • Опубликовано: 24 дек 2024

Комментарии • 57

  • @samsonblack
    @samsonblack 3 года назад +1

    I enjoy the way you manipulate these symmetric polynomials with such facility!

  • @diogenissiganos5036
    @diogenissiganos5036 3 года назад +6

    The first method is what I thought of initially and is pretty straightforward. The second solution is unrealistically concise! Well done once again!

  • @anisbm8873
    @anisbm8873 3 года назад +1

    17 days without a single geometry problem. It's not that I don't like algebra but I love geometry and I enjoyed the geometric problems you post on your channel. I wish to see them back again quickly. Anis from Algeria.

    • @SyberMath
      @SyberMath  3 года назад

      Sure. I understand. I will do a geometry puzzle after tomorrow. and you're the first person to know that!
      🙂

    • @dhruvladdha4789
      @dhruvladdha4789 3 года назад +2

      @@SyberMath nahh i saw it before him :D am the first xD

    • @SyberMath
      @SyberMath  3 года назад +1

      @@dhruvladdha4789 Oh ok! 😁

  • @242math
    @242math 3 года назад +1

    The first way was straightforward and easier for me to follow. Love algebra.

  • @amiyabora1011
    @amiyabora1011 3 года назад +1

    I solved it in 5 sec
    It is directly a formula see
    We know:-
    (a+b) (b+c) (c+a) = a²b+ab²+b²c+bc²+a²c+ac²+2abc
    If we add abc to rhs it will be
    a²b+ab²+b²c+bc²+a²c+ac²+3abc which is
    (a+b+c) (ab+bc+ca)

  • @echandler
    @echandler 3 года назад

    Great video. Note that Vieta’s formulas involve the elementary symmetric polynomials, an interesting subject in itself.
    Also note that your identity shows up in (x+y+z)³ = x³+y³+z³+3(x+y)(x+z)(y+z).

  • @HemantPandey123
    @HemantPandey123 3 года назад

    Put x+y+z = 0 we get function as zero. Means x+y+z is a factor. By symmetry and inspection next bracket can be guessed.

  • @MathElite
    @MathElite 3 года назад +4

    I saw on your Twitter that you are into Cybersecurity
    Ironically as I'm typing this, I'm in Cybersecurity university course
    this video seems interesting :D

    • @SyberMath
      @SyberMath  3 года назад +1

      That's interesting! Do we follow each other?

    • @MathElite
      @MathElite 3 года назад

      ​@@SyberMath Hey I just made a twitter account and followed you. I tweeted you
      Can you follow me back?

  • @snejpu2508
    @snejpu2508 3 года назад

    I used exactly the first method, but the second one is interesting as well. I knew it has something to do with Vieta's formulas. Nicely done.

  • @arifulhasan1558
    @arifulhasan1558 3 года назад

    Hey, I've learnt something new from your video and it is the method no. 2.It was really very interesting

  • @呂永志
    @呂永志 3 года назад

    Take x=-y-z, we have (-z)*(-y)*(y+z)+(-y-z)yz=0. So, the formula has the factor x+y+z. Then we can use method 2 in progress.

  • @wesleydeng71
    @wesleydeng71 3 года назад +1

    I have a somewhat nasty solution that requires no finesse. Let it = 0 and use the quadratic formula to solve for x. There are two roots: x=-(y+z) and x=-yz/(y+z). From there you have the factors.🤣

    • @SyberMath
      @SyberMath  3 года назад +1

      That's interesting!

  • @carloshuertas4734
    @carloshuertas4734 3 года назад

    Another great explanation!

  • @timetraveller2818
    @timetraveller2818 3 года назад +4

    wow that second method was AMAZING Everything just cancelled with it's additive inverse

    • @SyberMath
      @SyberMath  3 года назад +1

      Yeah, I like the second method because it's the Vieta way!

    • @thebammer5166
      @thebammer5166 3 года назад +1

      @@SyberMath I prefer the first method. It is easier to understand, even if it takes longer. The only reason I say that is because I am not familiar with the Vieta Way.

  • @Thomas-wi6si
    @Thomas-wi6si 3 года назад

    I distribute the terms also but i rewrite the sum as a quadratic with x as the variable
    (y+z)x^2 + ( y^2 + 3yz + z^2 )x + yz(y+z) => (y+z)x^2 + (y+ z)^2*x + yz*x + yz(y+z) =>
    (y+z)x*( x + (y+z) ) + yz*( x + (y+z) ) => ( x + (y+z) )*( (y+z)x + yz ) =>
    (x+y+z)(xy+yz+xz)
    Also great video

  • @vivekbhutada3049
    @vivekbhutada3049 3 года назад

    Second method was the one which I used to factor this equation by seeing in the thumbnail. Just using a instead of b

  • @schoolofmathematicsandscie766
    @schoolofmathematicsandscie766 3 года назад

    Excellent vid. I liked the second method👍

    • @SyberMath
      @SyberMath  3 года назад +1

      Glad you liked it!

  • @timetraveller2818
    @timetraveller2818 3 года назад

    Second method just shows the beauty of Algebra MIND BLOWN

  • @manojsurya1005
    @manojsurya1005 3 года назад

    Nice one

  • @sanjaysurya6840
    @sanjaysurya6840 3 года назад

    "Can you find the factor(s) or try to factorize", should be the question..

    • @timetraveller2818
      @timetraveller2818 3 года назад

      alternative: factorise (in the UK)

    • @SyberMath
      @SyberMath  3 года назад

      'factor' can be used as a verb as well as a noun!

  • @dominiquebercot9539
    @dominiquebercot9539 3 года назад

    Ça y est, j’ai trouvé !!!!

  • @r-star6140
    @r-star6140 3 года назад

    nice question

  • @shreyan1362
    @shreyan1362 3 года назад

    seems easy but requires a bit of thinking

  • @tonyhaddad1394
    @tonyhaddad1394 3 года назад +1

    Amazing problem !!!!!!
    [(x+y+z)-z][(x+y+z)-y][(x+y+z)-x] + xyz
    Finaly you get -xyz and all the rest term have (x+y+z) as factor so we get finaly (x+y+z)(xy+xz+yz) and yay!!!🎉🎊🎉🎊