Factoring 4th Degree Polynomials with Synthetic Division

An introduction to synthetic division and how to factor 4th degree polynomials

Пікірлер: 167

  • @collinsmith7572
    @collinsmith75727 жыл бұрын

    Thanks for the refresher. I was doing nth order differential equations and needed to remember how to do this since I haven't done it in ages. Life saver, man! Thanks

  • @fwogboy

    @fwogboy

    7 жыл бұрын

    Collin Smith Same!! If only I could remember every little math lesson I've learned...

  • @jwloohou2

    @jwloohou2

    2 жыл бұрын

    5 years later and I'm watching this for the exact same reason.

  • @mythics102
    @mythics1029 жыл бұрын

    You're about 2000 times better at teaching this than my actual teacher is. THANK YOU SO MUCH

  • @CompleteRandomness22
    @CompleteRandomness229 жыл бұрын

    oh my god, i didn't know that using synthetic division could solve so much!!! I didn't even think of just keep going down further till it hit the quadratic formula!!!!! THANK YOU!!!!

  • @tianxia1wushuang234
    @tianxia1wushuang2344 жыл бұрын

    Very Good! When solve fourth-order equation of one variable 2x^4+5x^3-5x^2-20x-12=0,the solution can continue appling synthetic division,for example -1| +2 + 5 - 5 - 20 -12 | - 2 - 3 + 8 +12 +2|+2 + 3 - 8 - 12 +0 | + 4+14+12 -2|+2 + 7 + 6 +0 | - 4 - 6 |+2 + 3 +0 So follow factorization,original equation can be changed into (x+1)(x-2)(x+2)(2x+3)=0 好棒! 当求解一个变量2x ^ 4 + 5x ^ 3-5x ^ 2-20x-12 = 0的四阶方程时,其可以连续应用综合除法,例如 -1| +2 + 5 - 5 - 20 -12 | - 2 - 3 + 8 +12 +2|+2 + 3 - 8 - 12 +0 | + 4+14+12 -2|+2 + 7 + 6 +0 | - 4 - 6 |+2 + 3 +0 因此,遵循因式分解,可以将原始方程式变为 (x + 1)(x-2)(x + 2)(2x + 3)= 0

  • @MattCollisMusic
    @MattCollisMusic7 жыл бұрын

    Thanks..good teaching ...nice pace

  • @DJ-ks7sh
    @DJ-ks7sh10 жыл бұрын

    AWESOME! I'm a math tutor and it's been awhile since I did grade 12 advanced functions; felt like a tool not knowing this

  • @evank7
    @evank74 жыл бұрын

    thank you sir. taking differential equations and getting into higher order stuff...somehow i never learned how to deal with higher order polynomials...now i know. Thanks man!!!!

  • @fikirsamuel1607
    @fikirsamuel16073 жыл бұрын

    Was about to take a test on simplification of rational equations. Thanks this helped a lot!

  • @rajab4187
    @rajab41874 жыл бұрын

    tommorow is my linear algebra exam BSCS 3RD SEM AND I am watching it at 3 am. exam is at 8.45 am. and you helped me a lot

  • @nayasspace
    @nayasspace7 жыл бұрын

    Thank you very much ! I was searching for this 😥 Iam so thankfull to you sir !

  • @mf6921
    @mf69218 жыл бұрын

    I LOVE YOU! Thank you sooo much I was really stressing out with a similar problem I had, you really are a life saver! (:

  • @JawadMohiuddin
    @JawadMohiuddin9 жыл бұрын

    Thanks. This actually helped me. A big help!

  • @edisonh3093
    @edisonh30937 жыл бұрын

    you absolute legend! Thanks for the help

  • @TheKingOfHeartsIV

    @TheKingOfHeartsIV

    7 жыл бұрын

    you mean The Legend 27?

  • @kondavamshi8697
    @kondavamshi86978 жыл бұрын

    But guessing the factor takes time...

  • @DogeFrom2014

    @DogeFrom2014

    8 жыл бұрын

    +konda vamshi It does, but I'd always start with +-1 & 2 cause they are mostly factors for every number

  • @Rohitsurthi7

    @Rohitsurthi7

    8 жыл бұрын

    +R. W. yeah

  • @DogeFrom2014

    @DogeFrom2014

    7 жыл бұрын

    ^ thanks for bumping this into my notifications, really needed to review this as I won't be taking math courses anymore and don't wanna be math-illiterate.

  • @ashthepandao-o6924

    @ashthepandao-o6924

    7 жыл бұрын

    Mario Micallef you said exactly what my algebra teacher told us xD

  • @jackcoleman2131
    @jackcoleman21316 жыл бұрын

    Took me until this video to understand this, god bless you.

  • @abooja100
    @abooja1009 жыл бұрын

    Instead of doing synthetic division for each of the possible values you can just plug them into the x values in the equation and get the remainder.

  • @richardhall9815

    @richardhall9815

    7 жыл бұрын

    Synthetic division is quicker (unless you're using a calculator).

  • @jojo-nr3yb

    @jojo-nr3yb

    4 жыл бұрын

    @@richardhall9815 actualy no, i can do synthetic divison in my head and replace the x by a number also in my head. I find that replacing the x is easier to calculate mentally, even though I can do both in my head. However, if you write it on paper, synthetic division is faster, and easier to do since you wont have to multiply as big of numbers, for example in most cases just by +/- 1 or 2

  • @RAPOLOGIST
    @RAPOLOGIST6 жыл бұрын

    Thank you so much man, that was so helpful!

  • @armanunited8120
    @armanunited81208 жыл бұрын

    Really helped me and I watched this video in class before the test and I am ready now thanks

  • @TheSurya81

    @TheSurya81

    4 жыл бұрын

    How much did you get in the test BTW

  • @luckzinxcadelices3159
    @luckzinxcadelices31597 жыл бұрын

    I swear this video helped me thank you so much

  • @ohsophie6391
    @ohsophie63918 жыл бұрын

    Thankyou for this! Finally get it

  • @miguelfreecs9095
    @miguelfreecs90956 жыл бұрын

    It helped me solving my daughters assignment..... nice

  • @gauthierla
    @gauthierla2 жыл бұрын

    Super helpful. Thank you very much.

  • @luckiestarz33
    @luckiestarz339 жыл бұрын

    Thank you! This helped me SO much!!! :)

  • @ys3395
    @ys33953 жыл бұрын

    Thank you so much for this!

  • @pragatins548
    @pragatins5489 жыл бұрын

    Thank you very much.. I was in hurry and it gave me clear idea in short time.. Thanks :-)

  • @lalitajoshi5350
    @lalitajoshi53505 жыл бұрын

    Good teaching :) thank you!!

  • @Magnus_E
    @Magnus_E9 жыл бұрын

    For your second example, you can continue the synthetic division for the second and first degree polynomials, right? This is always true I suppose? This way you find the roots -3 and -1\2 and 2 as a remainder so in the end you get the correct 2(x-4)(x+4)(x+3)(x+1\2). Is my thought valid in general?

  • @Shaikspeare0
    @Shaikspeare09 жыл бұрын

    What if you don't know the factors, so how would you know what you're dividing by. in the first example of synthetic division, you put a -3 because the factor was x+3. but it's not like we're gonna know the factor beforehand, so how would we do it?

  • @AKhoja

    @AKhoja

    9 жыл бұрын

    Kevin Shaik You're right, we don't always know what we're dividing by. The trick is to take the positive and negative factors of the constant term and use those as tests. It may seem inefficient at first, but with practice you'll be able to have intuition on what to do. (Basically, use trial and error)

  • @Shaikspeare0

    @Shaikspeare0

    9 жыл бұрын

    Adam Khoja oh you take the factors. alright. thanks.

  • @ashthepandao-o6924
    @ashthepandao-o69247 жыл бұрын

    would another good way be typing in the formula in the ti 86 calculator and check table and find where the y is 0 and use the x value

  • @jerryqin4459
    @jerryqin44596 жыл бұрын

    so when you factored the 2nd time with the positive 2, that deviser (2) is the factor of 6 right, not 12? I understand that 2 is the factor of both 6 and 12 but say that the question have 2 terms that don't have 2 as the common factor. sorry if I'm confusing, I hope you understand my question, thx

  • @darkanser
    @darkanser11 жыл бұрын

    Thanks for the demonstration. I found that making a calculating table in Excel saves you a lot of paper.

  • @ankaiahgummadidala1371
    @ankaiahgummadidala13713 жыл бұрын

    Very interesting . Thanks a lot .

  • @ConstantineQ
    @ConstantineQ11 жыл бұрын

    thx this method is way better than long division

  • @karinaburgess3989
    @karinaburgess39893 жыл бұрын

    how did you factor the last part ? after the synthetic division (2x+1)

  • @marvinallen404
    @marvinallen40410 жыл бұрын

    you are blessing

  • @vishakandroid
    @vishakandroid9 жыл бұрын

    Thank you! 🙏

  • @pratiksakharkar8823
    @pratiksakharkar88237 жыл бұрын

    thanku this tutorial helped me a lot!!!!!!!!!!!!!!!!!!!!!!!!!!!

  • @Mageros
    @Mageros10 жыл бұрын

    In your second example, in looking for the second factor I used -3 instead and still ended up with the right answer. {-3*2=-6} {-1-6=-7} {-3*-7=21} {-25+21=-4} {-3*-4=12} {-12+12=0} Is it possible to have different factors like this, or did I make a mistake in my arithmetic?

  • @slaekgonzales5119
    @slaekgonzales51193 жыл бұрын

    Hello can this method be also applied to other polynomial degrees? Thank you

  • @martinacaprice3856
    @martinacaprice38563 жыл бұрын

    Thank you!!!

  • @derekolson7550
    @derekolson755010 жыл бұрын

    Thank you so much.

  • @kashurintellectual5623
    @kashurintellectual56236 жыл бұрын

    Thanks, was helpful. (But guessing the factor may take time if the constant term is too big)

  • @miryawer4023
    @miryawer40235 жыл бұрын

    Thanks sir .this trik helped me i am very happy

  • @alexandremelo2017
    @alexandremelo20176 жыл бұрын

    In the first case, dont we have to put a 2 behind de factors? Because of the highest degree number ?

  • @annasabat1526
    @annasabat15263 жыл бұрын

    incredible

  • @ramya9097
    @ramya90976 жыл бұрын

    Thank you soo much this helped me

  • @mohammedsuliman8186
    @mohammedsuliman81866 жыл бұрын

    طريقه رائعه جدا ...nice method

  • @pathansahil5393
    @pathansahil53935 жыл бұрын

    What to do when.constant factors and leadind coefficient factors equal

  • @kaydeejay21
    @kaydeejay218 жыл бұрын

    Thank you!!

  • @HAtiger1
    @HAtiger19 жыл бұрын

    thank you very much

  • @anaslife_official
    @anaslife_official4 жыл бұрын

    Nice video too 💕

  • @PanookyDooky
    @PanookyDooky7 жыл бұрын

    find m, and the roots of X^3+mX^2-16X+48 ? :( help?

  • @David-xq3bg
    @David-xq3bg5 жыл бұрын

    How do you know if a factor is a root more than once?

  • @melinahafelt2591
    @melinahafelt25918 жыл бұрын

    can you do that on every degrees?

  • @benten5682
    @benten568211 жыл бұрын

    Really nice, Thanks a lot..

  • @sachinvashisth1491
    @sachinvashisth14915 жыл бұрын

    It's really helpful

  • @mangeshmalgi279
    @mangeshmalgi2796 жыл бұрын

    Great trick Thanks 👍

  • @gjennifer8887
    @gjennifer88874 жыл бұрын

    How did you get 1/2 and 3/2?

  • @dvinedzine
    @dvinedzine4 жыл бұрын

    Where did you get the -2 from?

  • @roeiohayon4501
    @roeiohayon45017 жыл бұрын

    is there a way to find the numbers not by guessing them?

  • @DavidAnatolie
    @DavidAnatolie8 жыл бұрын

    Thanks, my textbook didn't even mention the Rational Roots Test!

  • @jjeon9850
    @jjeon98509 жыл бұрын

    What's he rational ruths test?

  • @sebastiaankimman3925
    @sebastiaankimman39257 жыл бұрын

    thanks for the help

  • @abidashakir7879
    @abidashakir78795 жыл бұрын

    Does it work for ever? I have a question that it does not workl

  • @Perseverance108
    @Perseverance1084 жыл бұрын

    Thank you

  • @fas0f
    @fas0f8 жыл бұрын

    Am i the one wondering how did he solve the quadratic equations so fast ?

  • @jasonchan7319
    @jasonchan731910 жыл бұрын

    Thanks man!!!

  • @larryschmidt
    @larryschmidt11 жыл бұрын

    You don't have to do the rational roots test over again--because all the factors of -12 and 2 are included in the list you generated of factors of -48 and 2. So you can use that same list and just ignore the numbers greater than 12.

  • @gopichand2881
    @gopichand28816 жыл бұрын

    thank you

  • @afranshareefazeez
    @afranshareefazeez7 жыл бұрын

    Thank you so much😃

  • @Arfainali
    @Arfainali8 жыл бұрын

    how to find factors of m^4-2m^3+3m^2-2m+1=0

  • @bapibasak2842
    @bapibasak28425 жыл бұрын

    Is this method applicable for any degree polynomials?

  • @aaronemmanuel9431
    @aaronemmanuel94319 жыл бұрын

    Thanks man...Helped me much!!!!!!!

  • @MangKolokoy333
    @MangKolokoy33310 жыл бұрын

    you can also plug in the possible factors to the expression, and if it equals to zero, that number you plug in to the expression is a factor. the equal zero simply means zero remainder....just to save you sometime:)

  • @tianxia1wushuang234
    @tianxia1wushuang2344 жыл бұрын

    tianxia1wushuang234-天下第一文何文之原帖: Solve fourth order equation of one variable by synthetic division 2x^4+7x^3-29x^2-112x-48=0 Solve: From relationship between root and modulus of polynomials,people know that the roots of the original equation may be "+1-1+2-2+3-3+4-4+6-6+8-8+12-12+16-16+24-24+48-48......" Lucky take -3 +4 -4 -3| +2 +7 -29 -112 -48 | -6 - 3 + 96 +48 +4|+2 +1 -32 -16 + 0 | +8+36 +16 -4|+2 +9 +4 +0 | -8 - 4 |+2 +1 +0 So original equation can be changed into (x+3)(x-4)(x+4)(2x+1)=0 So x1=-3 x2=+4 x3=-4 x4=-1/2 Verify:x1=-3 or x2=+4 or x3=-4 or x4=-1/2 are all the root of the original equation 用合综除法求解一个变量的四阶方程2x ^ 4 + 7x ^ 3-29x ^ 2-112x-48 = 0 解答: 从多项式的根与系数之间的关系,人们知道原始方程的根可能是“ + 1-1 + 2-2 + 3-3 + 4-4 + 6-6 + 8-8 + 12- 12 + 16-16 + 24-24 + 48-48......“ 幸运抽取-3 +4 -4 -3| +2 +7 -29 -112 -48 | -6 - 3 + 96 +48 +4|+2 +1 -32 -16 + 0 | +8+36 +16 -4|+2 +9 +4 +0 | -8 - 4 |+2 +1 +0 因此原始方程式可以变为(x + 3)(x-4)(x + 4)(2x + 1)= 0 所以 x1 = -3 x2 = + 4 x3 = -4 x4 = -1 / 2 验证:x1 = -3或x2 = + 4或x3 = -4或x4 = -1 / 2都是原始方程式的根

  • @IzzyMonroe
    @IzzyMonroe10 жыл бұрын

    Aw. Yes thank you ^.^

  • @60nphi65
    @60nphi655 жыл бұрын

    Good video

  • @asimsyed2211
    @asimsyed22118 жыл бұрын

    better than my high school teacher..

  • @MyThundermuffin
    @MyThundermuffin9 жыл бұрын

    THANK YOU SIR :D

  • @KnightofArab
    @KnightofArab7 жыл бұрын

    what about complex numbers?

  • @l3aIIin23
    @l3aIIin238 жыл бұрын

    thanks

  • @QAJafri
    @QAJafri9 ай бұрын

    Sir how we get 2nd line

  • @viswanathancr349
    @viswanathancr3493 жыл бұрын

    good video

  • @harininadig.s2992
    @harininadig.s29927 жыл бұрын

    Thank u 😁😊

  • @Just1MorePerson1
    @Just1MorePerson18 жыл бұрын

    ty love you

  • @MikeTFresh
    @MikeTFresh9 жыл бұрын

    Thanks! But what if you don't have a constant term and you can't do the rational roots test?... such as finding all roots for f(x)= 6x^4-5x^3-4x^2

  • @Farazj7

    @Farazj7

    9 жыл бұрын

    then take an x out as a factor

  • @abhishekbaba7823
    @abhishekbaba78236 жыл бұрын

    shukriya sir :-)

  • @masorich5888
    @masorich58887 жыл бұрын

    What if none of the factors work?

  • @jessicanjemo432
    @jessicanjemo4325 жыл бұрын

    Where does the 1 in the last answer

  • @armagaan007
    @armagaan0075 жыл бұрын

    Damn ! It works

  • @jurajojo2543
    @jurajojo25437 жыл бұрын

    So can it happen that there is no factor that will give you the remainder 0?

  • @mustafarashad7353

    @mustafarashad7353

    7 жыл бұрын

    If that happens then that means that the equation that you are trying to simply cannot go simplification anymore.

  • @jasonophee6153
    @jasonophee61538 жыл бұрын

    how would you determine the factors of 6x^4 + 11x^3 - 35x^2 - 34x +k

  • @jasonophee6153

    @jasonophee6153

    Жыл бұрын

    @@kfjfkeofitorhf9520 this was seven years ago I don't even remember the context in which I asked

  • @Michael-rn6wo
    @Michael-rn6wo8 жыл бұрын

    solve this 3s^4 + 26s ^3 + 77s^2 + 84^s +24 .. i dont think what u exlained can help me

  • @ianpaoloofina6821
    @ianpaoloofina68217 жыл бұрын

    at 8:42... how did -4 turn into positive 4 which you have wrote into the factor of ( x + 4 )?

  • @LeedsGoNasty

    @LeedsGoNasty

    7 жыл бұрын

    -4+4=0

  • @zain4019

    @zain4019

    7 жыл бұрын

    Ian Paolo Bueno it makes more sense if you think of like this: The factor you chose was 4, so x=4 Now, subtract the 4 from either side and you get (x-4)

  • @carterreed4676

    @carterreed4676

    7 жыл бұрын

    Ian Paolo Bueno the multiplier is k {from (x-k)} so if k was -3 it would be {x-(-3)} therefore changing into (x+3)

  • @coolman612
    @coolman61210 жыл бұрын

    Why did he use the fractions as one of the possible X

  • @swetagollamudi6421

    @swetagollamudi6421

    10 жыл бұрын

    he divided the factors of the constant w/ the co-ef of the variable having the highest power..factors of 12 are 1,2,3,4,6,12.if u divide each with 2, which is the co ef of x^4, u get 1/2,2/2(=1),3/2,4/2(=2) and so on.

  • @feigao5839
    @feigao58397 жыл бұрын

    why 2x^2+ 5x +3 = (2x+1)(x+3)?

  • @gouzacastro7293

    @gouzacastro7293

    7 жыл бұрын

    FEI GAO this is 2x^2 + 6x + 3.

  • @swastikray1430
    @swastikray14304 жыл бұрын

    Plz Factorise: m^4+6m^3+11m^2+6m+1 It is factorising. Plz solve this...!!!

  • @JerimiahMayle
    @JerimiahMayle6 жыл бұрын

    Where does he get (x+3)(x+3) at?

  • @dayday3597

    @dayday3597

    6 жыл бұрын

    You can easily factor x^2+6x+9 using the “x methods” which only works for those equation

  • @damianradinoiu4314
    @damianradinoiu43149 жыл бұрын

    what if your polynomial doesnt have factors of the first degree like (x-3) or (2x+1).... take for example x^4+x^2+1... how do you factor this ?

  • @sk8terman37

    @sk8terman37

    9 жыл бұрын

    then in the synthetic division problem you would set it up with zeros as place holders for the missing numbers (i.e. if you have x^4+x^2+1 you would set it up with 1,0,1,0,1 if that makes sense. he explained it in the beginning of the video

  • @damianradinoiu4314

    @damianradinoiu4314

    9 жыл бұрын

    I did that, but what next ? can you make an attempt to solve it ? you'll see what I'm talking about

  • @DrMdini

    @DrMdini

    9 жыл бұрын

    I'm having the same problem.

  • @damianradinoiu4314

    @damianradinoiu4314

    9 жыл бұрын

    Mark Di Nicola it turns out x^4+x^2+1 factors into (x^2+x+1)(x^2-x+1) ,but i have no idea why because it fails the rational root test so it's kinda hard to factor it

  • @damianradinoiu4314

    @damianradinoiu4314

    9 жыл бұрын

    by the way, try x^5+x^4+1 also

  • @princerajsingh2792
    @princerajsingh27927 жыл бұрын

    4x4 + 3x3 - 15x2 + 13x + 16 = 0 please solve this equation