How to find the roots of a polynomials by factoring

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  • čas přidán 14. 03. 2015
  • 👉 Learn how to find all the zeros of a polynomial. A polynomial is an expression of the form ax^n + bx^(n-1) + . . . + k, where a, b, and k are constants and the exponents are positive integers. The zeros of a polynomial are the values of x for which the value of the polynomial is zero.
    To find the zeros of a polynomial, we first equate the polynomial to 0 and then use our knowledge of techniques of factoring polynomials to factor the polynomial. After we have factored the polynomial, we can then use the zero-product property to evaluate the factored polynomial and hence obtain the zeros of the polynomial.
    Recall that the zero-product property states that when the product of two or more terms is zero, then either of the term is equal to 0.
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    Organized Videos:
    ✅Zeros of a Polynomial by Factoring
    • Zeros of a Polynomial ...
    ✅Zeros and Multiplicity of Polynomials | Learn About
    • Zeros and Multiplicity...
    ✅How to Find all of the Zeros by Sum and Difference of Two Cubes
    • How to Find all of the...
    ✅How to Find all of the Zeros by Grouping
    • How to Find all of the...
    ✅How to Find all of the Zeros in Factored Form
    • How to Find all of the...
    ✅How to Find all of the Zeros by Factoring 5th Degree
    • How to Find all of the...
    ✅How to Find all of the Zeros by Difference of Two Squares
    • How to Find all of the...
    ✅How to Find all of the Zeros by Factoring 4th Degree
    • How to Find all of the...
    ✅How to Find all of the Zeros of a 3rd Degree Polynomial
    • How to Find all of the...
    ✅How to Find all of the Zeros Without Factoring
    • How to Find all of the...
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Komentáře • 95

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    @aquacultureeducation6542 Před 3 lety +108

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    @shard7572 Před 2 lety +24

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  • @joshua8417
    @joshua8417 Před 3 lety +65

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    @shashwatsinghchauhan Před 4 lety +41

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  • @applessauce7961
    @applessauce7961 Před rokem +13

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    @olukiyesimi Před 3 lety +92

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    @marryanne8701 Před 3 lety +18

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    @kachelampepo9297 Před 3 lety +1

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  • @jaxxonx3877
    @jaxxonx3877 Před rokem +2

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  • @resistanceisfutile520
    @resistanceisfutile520 Před 9 měsíci +4

    I still dont get it.

  • @SammyyNico
    @SammyyNico Před 4 měsíci

    this guy is the reason i’m not failing my test tomorrow.

  • @valentinarodriguez4384
    @valentinarodriguez4384 Před 4 lety +12

    1:22 what technique was used? I've never seen it before

  • @maxwellmagazi4268
    @maxwellmagazi4268 Před 2 lety

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  • @shreyaps951
    @shreyaps951 Před 3 lety +3

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    @romtf9266 Před rokem

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  • @AmCanTech
    @AmCanTech Před 2 lety

    thanks

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    @djhon3844 Před 3 lety

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  • @shivsc6167
    @shivsc6167 Před 11 měsíci

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    @stephsmith7638 Před rokem

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    @joharibacolod165 Před 3 lety +6

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  • @wintanahabtu7259
    @wintanahabtu7259 Před 3 lety

    Okay one question plsss answer it for me if you know it,
    If the answer we got is 3 we can write in a factor form as(X-3) right? What about if we get a zero how to we write it in a factor form????

    • @maryfahmy2141
      @maryfahmy2141 Před 2 lety

      Yes if it’s positive 3 then it would be (x-3) the zero is the same (x+0) or (x-0) it doesn’t matter in the end because 0+0=0 and 0-0=0

    • @CurryMuncher2
      @CurryMuncher2 Před rokem +1

      factor of 0 is just (x+0), or (x)

  • @samlynn7681
    @samlynn7681 Před 2 lety +1

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    @aurelia8028 Před 9 měsíci

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  • @kamoryesantana5019
    @kamoryesantana5019 Před 3 lety +10

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  • @arshaqrazeen8465
    @arshaqrazeen8465 Před 3 lety +2

    HOW MANY REAL ROOT DOES THE POLINOMIAL X^4+3X^2+5 HAVE?

  • @youtubeaccount0x073
    @youtubeaccount0x073 Před 3 lety +2

    How would you do x^6-7x^3-8 = 0

    • @hubertmonzon7223
      @hubertmonzon7223 Před 3 lety +2

      raise it to three instead of (what he did) 2.

    • @hubertmonzon7223
      @hubertmonzon7223 Před 3 lety

      (x^3-8)(x^3+1)

    • @youtubeaccount0x073
      @youtubeaccount0x073 Před 3 lety +2

      @@hubertmonzon7223 yes that only factors to 2 factors. But the end result would be 6 factors if done correctly.
      I just found that there is another formula

    • @powerdriller4124
      @powerdriller4124 Před 2 lety +1

      It is an interesting equation, it´s solutions are vertices of two equilateral triangles in the complex plane. You have to know and be comfortable with complex numbers, are you? If you are, then: Let y = x^3 , then the equation transforms to : y^2 - 7y - 8 = 0. A quadratic equation where you can use the quadratic formula. Once you get the two solutions of "y" you have to find the cubic root of "y", Three solutions for each, for a total of six solutions. Solutions X = -1, -2, -1 ± (3)^(1/2)*sqrt(-1) , +.5 ± 1*sqrt(-1)

    • @CurryMuncher2
      @CurryMuncher2 Před rokem +1

      @@youtubeaccount0x073 2 real solutions, 4 complex solution. it is 6 solutions not factors. (some factors are quadratic, and have 2 solutions)

  • @jakecathey7061
    @jakecathey7061 Před 6 měsíci

    saving my algebra 2 grade

  • @graduatedmaths
    @graduatedmaths Před 2 lety +1

    find roots of x^4-2x^3+2x^2+1=0 .... please

  • @sakatagintoki5562
    @sakatagintoki5562 Před 3 lety +4

    What if the only thing they have in common is a 1?
    For example: x^3 + 4x^2 - 20x - 48

    • @cantthinkofaname7525
      @cantthinkofaname7525 Před 3 lety

      my question exactly

    • @CurryMuncher2
      @CurryMuncher2 Před rokem +3

      rational root theorem.
      for any polynomial, a possible rational root can be expressed as (+-)(p/q), where p is a factor of the constant term, and q is a factor of the coefficient of the largest degree term.
      in this case, the constant term in -48, but since the theorem accounts for plus or minus, we can just factor 48.
      1x48
      2x24
      3x16
      4x12
      6x8
      since the coefficient of the largest term is just one, we don't need it, so the numbers listed above, and there negative counterparts, are possible roots for the polynomial. after plugging in many numbers, and after a lot of trial and error, we can figure out one root of the polynomial is -2. now that we know one root of the polynomial is -2, we know one factor of the polynomial is (x+2). this means we can divide the polynomial by (x+2), end up with a quadratic, and factor that normally. although that is pretty easy, I will also demonstrate how to do that.
      dividing polynomials, and demonstrating it using a keyboard and mouse, in a CZcams comment section is too hard, so just watch a CZcams video on that.
      if we divide the polynomial, we get x^2+2x-24
      lets use CTS
      x^2+2x=24
      x^2+2x+1=25
      (x+1)^2=25
      x+1=5 x+1=-5
      x=4 x=-6
      so there you go. using rational root theorem we can figure out the roots of the polynomial, and they come to be -2, 4, and -6.
      if you have any other questions feel free to reply.

  • @andrewm6424
    @andrewm6424 Před 11 měsíci

    Bonus fact: Both of those factors from the x^4 factorization could also have been factored again, because each factor was a difference of squares.

    • @andrewm6424
      @andrewm6424 Před 11 měsíci

      But, in this case, it was faster to just take the root of both sides because they were simple squares.

  • @magalyhinojozabarrera5448

    I need this now on reverse, I have to find 2 possibilities for p(x) if it has 3 roots x= 5, x= -10 and x= 0 😭😭😭 I don't know how to

    • @Frost59
      @Frost59 Před rokem

      Still need help?--

  • @annamacphee6397
    @annamacphee6397 Před 2 lety

    i love u sm

  • @yusufi2542
    @yusufi2542 Před 2 lety +1

    "And guess what? That works now" hehehe

  • @TheZteach
    @TheZteach Před 6 měsíci

    Wow

  • @angelicacanlas2032
    @angelicacanlas2032 Před 3 lety

    How about 3x³+24x²+48x

    • @CurryMuncher2
      @CurryMuncher2 Před rokem +1

      just take out a 3x, and solve like a quadratic

  • @lors4336
    @lors4336 Před 2 lety +1

    Sir can I ask why u didn't factor the (x^2-4) and (x^2-4) with the factoring technique sum of the difference of two squares? In that case u can get all real roots? Can I get u'r response to end my confusion???

    • @CurryMuncher2
      @CurryMuncher2 Před rokem +1

      he used plus and minus, but i agree with you, he shouldve factored

  • @elielmathe
    @elielmathe Před 2 měsíci

    Not sure you are right on x = -2 or x=2, it should have been 2

  • @Tyler-qp6rc
    @Tyler-qp6rc Před 3 lety +1

    should have dropped the pen at the last

  • @prashudwivedi99
    @prashudwivedi99 Před 4 lety +3

    Love from India 🥰

  • @belamagalhaes7325
    @belamagalhaes7325 Před 4 měsíci

    HOW DID HE GET A 4 IN THE BEGINNING GUYS IM SO CONFUSED

  • @mflewnari3997
    @mflewnari3997 Před 2 lety +3

    Guys can someone answer my Question
    Find the roots of each equation by factoring
    1. 15a³ - 9a² = 0
    2. 8x⁴ = 6x³
    3. 12a² + 12a = 0
    4. x² + 3× - 4x - 12 = 0
    I cant understand this, my teacher is too lazy to teach us and just gives us works without teaching 😩

  • @ashupashu5559
    @ashupashu5559 Před 2 lety

    This is an SAT question lol

  • @rafifasif373
    @rafifasif373 Před 4 lety +1

    According to other sites there is no x = 2 and -2 for an answer

    • @neylan4587
      @neylan4587 Před 2 lety

      Together +&- are normal to come

  • @cocoaloaff1093
    @cocoaloaff1093 Před 2 lety

    I feel so stupid I've been learning this for weeks now and I still don't get it. Idk why my brain doesn't get it.

    • @neylan4587
      @neylan4587 Před 2 lety +2

      First pretend to understand it the second time you will understand

  • @Laner7
    @Laner7 Před 3 měsíci

    I heard a bit of an accent come out of him at the very beginning of the video. Anyone else notice?

  • @aryanshankar3353
    @aryanshankar3353 Před 3 měsíci

    No wonder drop out rates are high...

  • @whipgame3137
    @whipgame3137 Před rokem

    Man this is so confusing .

  • @ClemonSchyrox143
    @ClemonSchyrox143 Před 7 měsíci

    bro why u always walk out after u solve the equation?