[Algebra] Derive the quartic formula

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  • Опубликовано: 8 дек 2022
  • In this video, we will derive the quartic formula (a.k.a. finding out the general solution of a degree 4 polynomial).

Комментарии • 66

  • @nightytime
    @nightytime Год назад +69

    Quartic polynomials are of degree 4, this video's duration is 44:44. Perfection.

  • @YoungPhysicistsClub1729
    @YoungPhysicistsClub1729 2 месяца назад +9

    bro hesitated to write the constant as 'e' in the thumbnail, relax nobody thought it was euler's number

  • @sagee_.r
    @sagee_.r Год назад +2

    Well done one 250 subsxribers! Keep up the good work!

  • @arnavdeep8396
    @arnavdeep8396 15 дней назад

    W channel, subscribed 👍

  • @mf-boomer
    @mf-boomer 5 месяцев назад

    You just got yourself a new subscriber :)

  • @leaDR356
    @leaDR356 25 дней назад +1

    I am your 722nd sub!

  • @ben5115
    @ben5115 7 месяцев назад

    Superb

  • @theneekofficial8829
    @theneekofficial8829 7 месяцев назад

    This seemed cool, youve got a new subscriber!

  • @DoctorSantosh
    @DoctorSantosh 8 месяцев назад +1

    Subbed. Thanks for the good content 👍

  • @cycklist
    @cycklist Год назад +3

    Goodness. Amazing video 👍

  • @abhaygvasista9433
    @abhaygvasista9433 2 месяца назад

    very cool

  • @ArpitaSinghBrollno
    @ArpitaSinghBrollno 8 месяцев назад +1

    You deserve more suscribers🥰

  • @bobbyheffley4955
    @bobbyheffley4955 9 месяцев назад +2

    If you can obtain a rational root for the resolvent cubic, it can simplify work.

    • @kobethebeefinmathworld953
      @kobethebeefinmathworld953  8 месяцев назад

      Not exactly. It needs some kind of symmetry with conditions that only degrees 4 and below fit, but not 5 or above

    • @bobbyheffley4955
      @bobbyheffley4955 8 месяцев назад

      @kobethebeefinmathworld953 if lambda is rational and positive, then the solutions to the quartic involve the following possibilities: integers, fractions, and expressions with square roots.

    • @kobethebeefinmathworld953
      @kobethebeefinmathworld953  8 месяцев назад

      @bobbyheffley4955 I thought you were referring to quintic equation. My mistake.
      Yes, that can reduce the solution into something nicer.

  • @calvinjackson8110
    @calvinjackson8110 23 дня назад

    Just get rid of the 3degree term by using a linear transformation like one did for cubic.

  • @extreme4180
    @extreme4180 8 месяцев назад +3

    is there a video for cubic formula?

  • @detectiveandspynovels7140
    @detectiveandspynovels7140 14 дней назад

    ♥️

  • @gigantopithecus8254
    @gigantopithecus8254 7 месяцев назад +1

    underated

  • @johannestan8681
    @johannestan8681 2 месяца назад

    Hi! I have a question. How did you come up with 3/8a^2x^2? I got 21/16a^2x^2 instead. Thanks for helping out in advance😊

    • @kobethebeefinmathworld953
      @kobethebeefinmathworld953  2 месяца назад

      Good question! It is based on the expansion of (x +a/4)⁴, the x² term of it would then be 6×x²×(a/4)²=(6/16)a²x²=(3/8)a²x²

    • @johannestan8681
      @johannestan8681 2 месяца назад

      @@kobethebeefinmathworld953 Great! I mislooked the 4^2 of a^2/4^2 when I multiplied it by x^2

  • @ignaziogiacobbe3747
    @ignaziogiacobbe3747 4 месяца назад

    Hi, I have a question, if the third degree equation in lambda, has no rational solutions; how should we proceed?

    • @kobethebeefinmathworld953
      @kobethebeefinmathworld953  4 месяца назад

      Good question. Lambda does not need to be rational in order to solve the quartic equation. In fact, since lambda is determined by the corresponding cubic equation, as long as we substitute the coefficients into the cubic formula, we can find out what lambda is.

    • @bobbyheffley4955
      @bobbyheffley4955 3 месяца назад

      ​@kobethebeefinmathworld953 of course, lambda must be nonzero

  • @steelbrotherhoodof2359
    @steelbrotherhoodof2359 Год назад

    zero is the second iteration, step, to solve the equation variable. too determine them. it is actually not zero.
    we add equal to zero to solve an unknown varable. it starts without. the = 0. wich is the first step. first literation. the whole formula is not equal to zero. but has a different answer. but this is probably not a formula. but points on a graphic out of a table. wich means their are individual coordinates. wich are unique units.

    • @steelbrotherhoodof2359
      @steelbrotherhoodof2359 Год назад

      x means x. until x is a number. x is a variable. a yet to defind number. otherwise it is just a... formula without an answer. just as is. it only make sense if you replace the numbers. with figures, numbers.

  • @per3868
    @per3868 9 месяцев назад +5

    At 500 subs you should derive the quintic formula :D

    • @carultch
      @carultch 8 месяцев назад

      Galois proved there can be no such thing.

    • @Alians0108
      @Alians0108 8 месяцев назад +1

      ​@@carultchAt 500 subs he should prove that there is no formula

    • @kobethebeefinmathworld953
      @kobethebeefinmathworld953  8 месяцев назад

      Correct!

    • @kobethebeefinmathworld953
      @kobethebeefinmathworld953  8 месяцев назад

      I'll wait until 2500

    • @bobbyheffley4955
      @bobbyheffley4955 6 месяцев назад

      Niels Henrik Abel proved that the quartic is the highest degree equation that has a general solution in radicals.

  • @Redzaryo01
    @Redzaryo01 8 месяцев назад +1

    I'm in third grade Middle school and this is complex meybe .. so i want to know , why we don't have ( ∆ ) like ax²+bx+c=0
    ∆=b²-4ac
    X1=(-b+√∆)/2a ou X2=(-b-√∆)/2a , if ∆ = 0 we have only one solution if he negative we have complex number but why and why we don't have this in ax⁴+...+e=0

    • @kobethebeefinmathworld953
      @kobethebeefinmathworld953  8 месяцев назад

      That's a very good question. The quick answer is: Yes, there is (sort of), which is the lambda that's used as a parameter of finding the roots of the cubic equation that yielded from the original quartic equation.

    • @Redzaryo01
      @Redzaryo01 8 месяцев назад

      @@kobethebeefinmathworld953 can you make videos for the solution of equation 3 , 4 , 5 degree or 3 , 4 please with this method ?

    • @Redzaryo01
      @Redzaryo01 8 месяцев назад

      @@kobethebeefinmathworld953 and thank you brother for reponse xD

  • @preciousmathematicsfun4331
    @preciousmathematicsfun4331 15 дней назад +1

    I'm your 444 liker,

  • @daniel_77.
    @daniel_77. 2 месяца назад

    my phone's battery is at 44%. perfect

  • @cristianwiththek1015
    @cristianwiththek1015 Год назад

    what do you do if λ = 0

    • @kobethebeefinmathworld953
      @kobethebeefinmathworld953  Год назад

      As a parameter, you can use any 1 of the 3 solutions of λ and yield the same 4 solutions of x, so you can try to use the nonzero λ to get the results. Now, if all 3 solutions of λ are equal to 0, it provides that all p, q, and r are equal to 0, implying that there are some kind of conditions for a, b, c, and d su h that you can simplify the original equation.

    • @Fluorineer
      @Fluorineer 9 месяцев назад +1

      more specifically, λ can only be 0 if the absolute term is 0. The absolute term is -q^2, but if q=0, that means we have a biquadratic equation which can be solved easily. When q≠0, we never get any zero-solutions for λ, so you never have to explicitly choose.

    • @bobbyheffley4955
      @bobbyheffley4955 9 месяцев назад

      ​@kobethebeefinmathworld953 if p, q, and r all equal 0, the original equation has four roots all equal to -a/4, since this implies that a, b, c, and d are all 0.

    • @kobethebeefinmathworld953
      @kobethebeefinmathworld953  9 месяцев назад

      @@bobbyheffley4955 Yes, that is correct.

    • @bobbyheffley4955
      @bobbyheffley4955 9 месяцев назад

      ​@Fluorineer if q is nonzero and you get a rational value for lambda, use it to simplify calculations.

  • @abhinavprabhakar455
    @abhinavprabhakar455 2 месяца назад +1

    44 minutes 💀💀💀

  • @VanNguyen-kx6gx
    @VanNguyen-kx6gx 6 месяцев назад +1

    Difficult to solve.

  • @islamkamal8557
    @islamkamal8557 Год назад +2

    Add Arabic subtitles to your videos please

    • @kobethebeefinmathworld953
      @kobethebeefinmathworld953  Год назад +1

      I will try to find a way to add the option, but I don't speak Arabic, so I need someone to type the subtitles for me.

    • @islamkamal8557
      @islamkamal8557 Год назад +6

      @@kobethebeefinmathworld953 deer sir you do not need to type subtitles youtube provides subtitles for videos .just activate it

  • @user-on7ct8em3m
    @user-on7ct8em3m 2 месяца назад

    👍👍🫡❤