Synthetic division example 2 | Polynomial and rational functions | Algebra II | Khan Academy

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  • เผยแพร่เมื่อ 6 ก.พ. 2025
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    Another example of applying the basic synthetic division algorithm
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ความคิดเห็น • 66

  • @timmypena241
    @timmypena241 4 ปีที่แล้ว +3

    everybody is doing online classes and my professor posted your video so we can continue our work. I'm glad she did.

  • @ramble21
    @ramble21 2 ปีที่แล้ว +2

    W khan academy

  • @danielmak4333
    @danielmak4333 12 ปีที่แล้ว +1

    Wow I learned this last semester and totally forgot how to do this. Thanks for the refresher!

  • @jayoncetaylor3610
    @jayoncetaylor3610 12 ปีที่แล้ว +4

    don't get me wrong, you've done an awesome job explaining how synthetic division is done, I'm just looking for the specific video that you said you that you have explaining why it all makes sense...

    • @rendobro274
      @rendobro274 2 ปีที่แล้ว +3

      I got your back bro just search this up "Why synthetic division works | Polynomial and rational functions | Algebra II | Khan Academy"

  • @erwinjedracho640
    @erwinjedracho640 10 ปีที่แล้ว +29

    man..how did they discover this....fuck bro, this isn't math, this is VODOO.....

  • @viet-anhle2440
    @viet-anhle2440 6 ปีที่แล้ว +2

    Lol in the first video example he was like in the next example we will show you how it's like voodoo and in this video he says the same thing again😂

  • @nii_san1201
    @nii_san1201 7 ปีที่แล้ว +2

    i like how he keeps the numbers colored rather than having them in just 1 boring color

  • @biganakan5508
    @biganakan5508 7 ปีที่แล้ว +1

    Thank you sooo much !

  • @adamarbab5152
    @adamarbab5152 7 ปีที่แล้ว +1

    Now I got it
    thanks!

  • @reinowarren7880
    @reinowarren7880 8 ปีที่แล้ว +7

    Sal claims that synthetic division works ONLY for x - k as a divisor, NOT SO. It also works for nx - k where the reference value is the solution to nx - k = 0, which is x = k/n.
    There is a slight twist: P(x)/ (nx - k) = P(x)/[n(x - k)] = (1/n)P(x)/(x - k/n). So the quotient of P(x)/(x - k/n) must be multiplied by 1/n (or if you wish, the coefficients must be divided by n).
    Try (8x³ + 2x² + 5x - 6)/(2x - 1): Using the reverence number ½ the original synthetic quotient is 8, 6, 8, with remainder -2. So the real quotient polynomial is 4x² + 3x + 4 and the remainder is -2. That is, (8x³ + 2x² + 5x - 6)/(2x - 1) = (4x² + 3x + 4) + -2/(2x - 1)

    • @investigate711
      @investigate711 6 ปีที่แล้ว

      Reino Warren thanks man, it really helps

  • @seajaey1
    @seajaey1 7 ปีที่แล้ว +1

    Thanks a lot! 👍

  • @Nickadoo500
    @Nickadoo500 7 ปีที่แล้ว

    useless stuff, but i got to know it for the next math quiz! thankyou khan!

  • @MrD3STR03R
    @MrD3STR03R 12 ปีที่แล้ว +1

    This is very helpful, Thanks! :D

  • @S1rjoemama
    @S1rjoemama 12 ปีที่แล้ว +1

    in the last video he says that the degree of the divisor must be 1. In other words in the denominator you can only have (x^1)+ a number

  • @jayoncetaylor3610
    @jayoncetaylor3610 12 ปีที่แล้ว +17

    Now... where's the video explaining WHY this all makes sense?

    • @salvadormarley75
      @salvadormarley75 3 ปีที่แล้ว

      you probably dont care but does anybody know a trick to get back into an instagram account?
      I was stupid forgot the account password. I appreciate any assistance you can offer me.

    • @jaxtynallan4195
      @jaxtynallan4195 3 ปีที่แล้ว

      @Salvador Marley Instablaster :)

    • @salvadormarley75
      @salvadormarley75 3 ปีที่แล้ว

      @Jaxtyn Allan thanks so much for your reply. I got to the site on google and im trying it out now.
      Seems to take a while so I will reply here later with my results.

    • @salvadormarley75
      @salvadormarley75 3 ปีที่แล้ว

      @Jaxtyn Allan it worked and I finally got access to my account again. Im so happy:D
      Thanks so much, you saved my account !

    • @jaxtynallan4195
      @jaxtynallan4195 3 ปีที่แล้ว

      @Salvador Marley glad I could help :)

  • @caliconfirmed3984
    @caliconfirmed3984 11 ปีที่แล้ว +8

    Forget this, wolfram alpha time -.-

  • @Sakurachan001
    @Sakurachan001 8 ปีที่แล้ว +9

    what if the numerical coefficient of the divisor is 2,3 and so on not 1 . like 2x-3 instead of x-3

    • @udithNRP
      @udithNRP 6 ปีที่แล้ว

      then x=3/2! Simple!!

  • @kunjankaim6250
    @kunjankaim6250 7 ปีที่แล้ว

    Really helped!!! Thanks

  • @gilbertmartinez9910
    @gilbertmartinez9910 9 ปีที่แล้ว +1

    Thanks khan academy for helping me with this now I can study in peace lol

  • @WhatsBliss
    @WhatsBliss 11 ปีที่แล้ว +6

    I actually prefer using synthetic division. I tend to make fewer mistakes and it feels like there's less to keep track of. :P

  • @beary605
    @beary605 12 ปีที่แล้ว +1

    but with the intuition he gives, that means there should be a way to divide by polynomials.

  • @uggmonster8795
    @uggmonster8795 8 ปีที่แล้ว +2

    You did not fully explain why we change the K in x+k and can be confusing. We set x+k=0 and solve for x. This would have been easier to explain so when you tell us variables being multiplied by a number make this more complicated when it is the same proceedure.

  • @niloofareshghi8780
    @niloofareshghi8780 8 ปีที่แล้ว +1

    is there a video with a second degree divisor?

  • @orizbethsolis3756
    @orizbethsolis3756 4 ปีที่แล้ว +1

    How did you get the [6x to the 3rd power]? It does not make sense? I thought when you dived exponent, you are really subtracting exponents. So, How did you get 6X to the third power?

  • @xTESTimonyx
    @xTESTimonyx 10 ปีที่แล้ว +26

    and this is why I hate math...

  • @beary605
    @beary605 12 ปีที่แล้ว +1

    Can you explain the method of synthetic division with polynomials, such as (4x^3-2x^2+4)/(2x^2+5x+1)?

  • @metroid_gauntlet
    @metroid_gauntlet 8 ปีที่แล้ว

    What do you do if x has a coefficient with it? Like x-3, what if you had 2x-3 instead, what would you have to do?

    • @romacarlos3401
      @romacarlos3401 8 ปีที่แล้ว

      he said in the video that it doesn't work if it has a coefficient.

    • @MarkCarrollGrumpyBear
      @MarkCarrollGrumpyBear 7 ปีที่แล้ว

      not true. it will work if it has a coefficient; you just have to divide the denominator by whatever the coefficient is to make it a coefficient of 1

  • @idsamuel
    @idsamuel 12 ปีที่แล้ว

    It's in informal Indonesian language though haha.
    By the way I've tried with more than binomials and it works! You just have to add the rows and do the same concept as in the video I gave.
    I'm relieved that Indonesia still has contributions to science and math in this case, so Khan Academy can you make a video about this? I'm sure it will help people and Sukino's work can be appreciated by more people in the world.

  • @prakashsolanki9116
    @prakashsolanki9116 7 ปีที่แล้ว +3

    What do you do if x has a degree with it

    • @cassialli1547
      @cassialli1547 6 ปีที่แล้ว

      Synthetic division won't work, so you have to do long division.

  • @kingle1775
    @kingle1775 10 ปีที่แล้ว +1

    Can you add a complex one with some thing divided by 2x-3?

    • @kingle1775
      @kingle1775 10 ปีที่แล้ว +1

      and it's not impossible

    • @Formula_Chase
      @Formula_Chase 8 ปีที่แล้ว +1

      Synthetic division only works with x's that have the coefficient of 1. You'd have to do long division.

    • @MarkCarrollGrumpyBear
      @MarkCarrollGrumpyBear 7 ปีที่แล้ว +1

      no, you wouldn't. you just need to reduce the coefficient of the x term to 1 by dividing the binomial by whatever the coefficient is.

  • @ranxu9832
    @ranxu9832 8 ปีที่แล้ว

    shouldn't it be minus during ring the synthetic division process rather than plus???

  • @samanthachan3241
    @samanthachan3241 11 ปีที่แล้ว

    so how will you be able to solve this:
    14x^4+3x^3+x^2-6x+2/x^2-9x+20

    • @MarkCarrollGrumpyBear
      @MarkCarrollGrumpyBear 7 ปีที่แล้ว

      that requires you to factor using synthetic division, which I learned about just recently. you need to take the factors of the constant term (plus or minus) and figure out what factors into the rest of the equation without the constant term using synthetic division. because it's a degree 4th polynomial, after you figure out what can factor into the equation, you need to factor it again using the x cubed polynomial and doing the same process as you did with the starting thing. you need to reduce it to an x squared term in order to have your whole answer, and if that x squared trinomial can factor further, then you need to factor it into its binomials.

  • @ashleymendez4533
    @ashleymendez4533 7 ปีที่แล้ว

    What happens if the equation not in order by exponents

  • @idsamuel
    @idsamuel 12 ปีที่แล้ว

    /watch?v=jqXSbmKn3gs
    The video is in Indonesian, but maybe you can watch the diagrams.
    It's called "Horner Kino", an addition to Horner's method to divide polynomials with binomials (or more i can't be sure) found by an Indonesian mathematician Sukino. Hope it helps ^^

  • @xavieraguinaldo3661
    @xavieraguinaldo3661 8 ปีที่แล้ว

    Is that a missing term

  • @josierosie8445
    @josierosie8445 10 ปีที่แล้ว

    Why did you compare it to voodoo?

  • @irismarchant6752
    @irismarchant6752 7 ปีที่แล้ว

    why does he separate the 487????

    • @f3lla776
      @f3lla776 7 ปีที่แล้ว

      Iris Marchant because it's the remainder

  • @rubycosmo6279
    @rubycosmo6279 6 ปีที่แล้ว +2

    This looks like voodoo.

  • @jasmineo7724
    @jasmineo7724 7 ปีที่แล้ว

    Why 487/x-3???

    • @shubhamjain1328
      @shubhamjain1328 7 ปีที่แล้ว

      Jasmine J that's what the logarithm says you separate out the last term from the answer and it is the remainder.

  • @SofieDiaz
    @SofieDiaz 9 ปีที่แล้ว

    Wait how did 160 become + 160 and how did 17x^2 become + 17x^2??

  • @jasonlong5097
    @jasonlong5097 6 ปีที่แล้ว +1

    who is the dude? I kind of want to know him.

  • @levanbichinashvili989
    @levanbichinashvili989 7 ปีที่แล้ว

    After watching this I realised how useless my professor is.......

  • @user-tw5ek1gg8j
    @user-tw5ek1gg8j 5 ปีที่แล้ว

    I understand everything except what is Voodoo?
    Are you referring to Wudu in Islam?
    How is this Wudu?