Partial fraction expansion 3 | Partial fraction expansion | Precalculus | Khan Academy

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    Dealing with repeated factors
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ความคิดเห็น • 99

  • @tonygorogo478
    @tonygorogo478 8 ปีที่แล้ว +43

    I didn't find this video " a bit helpful", I find it "very very very helpful". Thank you.

  • @CROFTYNESS
    @CROFTYNESS 13 ปีที่แล้ว +3

    Thank buddy, these are great refreshers for my exams on Monday and Wednesday!
    You describe and explain with the upmost excellence, and you’re clean and energetic in your voice. Great aid for thousands of students. Keep it up!

  • @MrShagification
    @MrShagification 8 ปีที่แล้ว +6

    It's easy if the cubic is something like in the video. But I'm having trouble when the cubic is something like (x+2)^3.
    I can find C, because A and B both = 0. However, when finding A, the B doesn't = 0 and vice versa.

  • @mathematiknet
    @mathematiknet 12 ปีที่แล้ว +1

    The problem in 10:10 is easy to solve. You can figure J, if you put x=a. Then differentiate the equation and put x=a again, to get I,H,G,F,E,D,C,B, A

  • @93stormer
    @93stormer 13 ปีที่แล้ว +2

    I don't know how I got to calculus without knowing how to do partial fractions, but I did. When I was taking integrals, I found that I needed to use this concept, but I didn't know how! Luckily, I had the Khan Academy, which explained partial fractions within a half hour. All I can say is: these videos can help you no matter where you are in your education. Salman Khan, you are the greatest!

  • @purpletosh
    @purpletosh 12 ปีที่แล้ว +10

    what a wizard... 'j' IS the tenth letter of the alphabet!

  • @dominator1699
    @dominator1699 3 ปีที่แล้ว +2

    crazy how a video from 2009 is still better than teachers in 2021

  • @abhishekravindra4008
    @abhishekravindra4008 6 ปีที่แล้ว +3

    he idk and gets it spot on J letter 9:57

  • @BadMouton
    @BadMouton 13 ปีที่แล้ว

    I seldom write comments on youtube since its usually pointless, but I sincerely thank god that there are ppl like you in this world, so keep on the good work and rest easy knowing that you're helping a lot of people. Thanks!

  • @Tuffadandem
    @Tuffadandem 9 ปีที่แล้ว +2

    Sal you are a legend! Thank you so much for these videos.

  • @johnholme783
    @johnholme783 ปีที่แล้ว +1

    There’s another method of solving partial fractions, it’s called equating the coefficients. I use whatever method is simpler for the particular problem.

  • @aparrotslife
    @aparrotslife 15 ปีที่แล้ว +1

    I cannot thank you enough! You're going to help me get an A in my precalculus class! You're my savior! :)

  • @HeeyWhitey
    @HeeyWhitey 11 ปีที่แล้ว +3

    Sal, you have saved me from certain failure!

  • @bebarshosnie8751
    @bebarshosnie8751 6 ปีที่แล้ว +3

    can't get enough of these intuitions 😂

  • @GangnamStyle60
    @GangnamStyle60 7 ปีที่แล้ว +3

    My life saver

  • @imegatrone
    @imegatrone 12 ปีที่แล้ว +1

    I Really Like The Video From Your Dealing with repeated factors

  • @Mcdonald390
    @Mcdonald390 11 ปีที่แล้ว +2

    Actually, this is no special case really as you can actually split the fractions normally as
    A/(x-1) + B/(x-2) + C/(x-2) and get the same answer.
    Why? Because all you need to do is add them in order like they appear, as:
    [A/(x-1) + B/(x-2) ]+ C/ (x-2)
    I find this method to be straight forward as all you do is carry out you usual cross multiplication. Just keep everything in brackets and choose your values for 'x' in that state as it saves you time rather than expanding the brackets.

  • @zynthealwavii5084
    @zynthealwavii5084 11 ปีที่แล้ว +1

    This guy is amazing hes funny and helpful,man my grades improved!

  • @SN1350
    @SN1350 13 ปีที่แล้ว

    I wonder if any college professors watch these videos and actually learn a thing or two about teaching, because I have seen some professors that SUCK at teaching.
    Thanks dude you kick some major ass.

  • @Rajivrocks-Ltd.
    @Rajivrocks-Ltd. ปีที่แล้ว

    First time I heard about this is in Calc 2 for integrating a fraction so now I am finding this vid very very helpful!

  • @AnaVazquez428
    @AnaVazquez428 12 ปีที่แล้ว

    Thank you for all of your help Sal. You are doing an amazing gob. I don't know how I would have gotten past Calculus without you.

    • @henrydacruz3857
      @henrydacruz3857 4 ปีที่แล้ว

      Thanks....so so so.much. this is why I.love TH-cam. When you don't understand it in class, u ll understand at TH-cam.... Bless u

  • @retuzziaro
    @retuzziaro 4 ปีที่แล้ว

    Thanks, Sal!

  • @Arham1716
    @Arham1716 2 ปีที่แล้ว

    Please sal Its a humble request to you please make a video on partial fractions with 5 constants
    .... It would be really useful

  • @vanmanforsman1
    @vanmanforsman1 12 ปีที่แล้ว

    check the first - you use long division, then express it as blah blah + remainder/divisor (the original denominator)

  • @owenferrera7295
    @owenferrera7295 8 ปีที่แล้ว

    great. the lecture provided to us was a bit confusing. this helped a lot

  • @DistortionCG
    @DistortionCG 8 ปีที่แล้ว +5

    I love you

  • @Catbuttttt
    @Catbuttttt 14 ปีที่แล้ว

    thankkkk you...God bless

  • @keeyishan1995
    @keeyishan1995 6 ปีที่แล้ว

    Thank you so much!

  • @lisagibbon
    @lisagibbon 14 ปีที่แล้ว

    as others have said previously and sincerely, thank you!

  • @katherinebcn
    @katherinebcn 13 ปีที่แล้ว

    Thank you! You explained it way better than my precalc teacher. Keep it up, finals are coming up soon hahah

  • @idknuttin
    @idknuttin 8 ปีที่แล้ว +3

    can we also solve this by doing A/(x-1) + (Bx+C)/(x-2)^2?

    • @theajayyy
      @theajayyy 4 ปีที่แล้ว

      A little late, but yes. Expand it and it is the same.

  • @Df994_
    @Df994_ 12 ปีที่แล้ว

    @2i20 This might be a little late but yeah he actually does. It's in partial fraction expansion part 1.

  • @hjfnation
    @hjfnation 11 ปีที่แล้ว

    that tutorial is quite useful as always

  • @nicholasm716
    @nicholasm716 10 ปีที่แล้ว

    THANK YOU SO MUCH SAL YOU ARE THE BEST PERSON EVER

  • @holyempire08
    @holyempire08 11 ปีที่แล้ว

    this is so helpful. urgh! exams tomorrow.. and I'm glad to say that this has helped me a lot. Keep it up :D

  • @TheChuggtom88
    @TheChuggtom88 14 ปีที่แล้ว

    thanks so much! i get it now!!!

  • @2i20
    @2i20 12 ปีที่แล้ว

    do u have a video explaining if the numerator's degree was bigger than the denominator's?

  • @PancakeMan123000
    @PancakeMan123000 12 ปีที่แล้ว

    With the third term of the decomposition: C/(x-2)^2, why is it possible to only use a constant for the numerator? In the previous video he said that the degree of the numerator had to be one less than the denominator, in which case the expression for the numerator would be Cx+D? Could someone explain please?

  • @MrMikees20
    @MrMikees20 13 ปีที่แล้ว

    Thks..

  • @Carebearbull
    @Carebearbull 12 ปีที่แล้ว +1

    @ledkeb
    lolol
    "Hairy", "hit the point home" and there's a third one as well.

  • @khwajaabdurrehman1375
    @khwajaabdurrehman1375 ปีที่แล้ว

    Isn't the numerator's degree supposed to be less than the denominator's before we can start expanding?

  • @TheeLavv
    @TheeLavv 12 ปีที่แล้ว +1

    can this guy teach me all of my subjects... forever....

  • @RooTHackera
    @RooTHackera 7 ปีที่แล้ว

    Thank you so much. I saved me .

  • @lemonsilled7156
    @lemonsilled7156 3 ปีที่แล้ว

    thank you sal

  • @minhazmahmud9315
    @minhazmahmud9315 7 ปีที่แล้ว +5

    sir, Why CX + D has not been used in place of C, in the partial fraction C/(x-2)^2 ? here numirator is 2nd degree.....!????

    • @martincattell6820
      @martincattell6820 6 ปีที่แล้ว +5

      I know your comment was 8 months ago but still: when the fractions are added together again, B will be multiplied by (x - 2) (to create like terms in its denominator) giving B(x + D) (D = -2) in the numerator anyway. So it is sort of taken care of by having (x - 2)squared under C.

    • @climbingcat
      @climbingcat 4 ปีที่แล้ว

      @@martincattell6820 Thanks :) After rewatching the vid, Sal does explain why 1.47 - 2.55

  • @MemeScreen
    @MemeScreen 6 ปีที่แล้ว

    Any way you could re-upload it or replace it with the ring in the audio taken out. I was able to do it with one filter in adobe audition. I just think others would appreciate it.

  • @blumpkin123456789
    @blumpkin123456789 13 ปีที่แล้ว

    hey i have a question how would you find the partial fraction of (2x+9)/(x^2+4x+20).
    I know theres no factors for the denominator so would u complete the square and get (x+2)^2 + 16?

  • @davidaq6
    @davidaq6 14 ปีที่แล้ว

    indeed the awesome is strong with this one

  • @SpenserF
    @SpenserF 11 ปีที่แล้ว

    by the reasoning at 2:34, where B/((x+2)^2) + C/(x+2) = (Bx+C)/((x+2)^2), shouldn't I be able to do A/(x-1) + (Bx+C)/((x+2)^2) and get an equally valid answer? Whenever I try this it doesn't come out

  • @PancakeMan123000
    @PancakeMan123000 12 ปีที่แล้ว

    actually I get it now!

  • @daniellindeque8701
    @daniellindeque8701 5 ปีที่แล้ว

    Thank you

  • @Kratos6798
    @Kratos6798 13 ปีที่แล้ว

    keeping it stylish

  • @MellowCruisin
    @MellowCruisin 12 ปีที่แล้ว

    It didn't look like the numerator was a lower degree than the denomenator in this one? Does it not matter because the denomenator was already factored? I am confused on this

  • @cheechiongfun
    @cheechiongfun 12 ปีที่แล้ว

    Hey what if you have a denominator value of x^2(x^2+1)?

  • @nkolatsis
    @nkolatsis 14 ปีที่แล้ว

    You have missed adding number 2 to the series.

  • @kugalojan
    @kugalojan 12 ปีที่แล้ว

    Thank you Khan sir :)

  • @mdshakhawathossain2668
    @mdshakhawathossain2668 8 ปีที่แล้ว

    thank you khan

  • @aGoooNeR
    @aGoooNeR 12 ปีที่แล้ว

    I was in class this morning and didn't know what the hell was going on. Now, everything is crystal clear. Thank you very much for these wonderful videos.

  • @jjimbodb
    @jjimbodb 13 ปีที่แล้ว

    thank you good sir :)

  • @luisdavid1989
    @luisdavid1989 11 ปีที่แล้ว

    What if my denominator cannot be factored? Can I still expand the fraction?

  • @TheMikarelax
    @TheMikarelax 8 ปีที่แล้ว

    does that work with : 1/(x+a)²= 1/ (x+a) + 1/ (x+a)² too ? i mean with + a place of -

  • @MultiGuitarman21
    @MultiGuitarman21 7 ปีที่แล้ว

    how would someone do the partial fraction of this Y(s) = (s+8)/(s+4)^2? I tried this method but i keep getting the wrong numerators. tried several problems actually and seem to only work on some problems. Im clearly doing something wrong. could someone help please thanks

  • @SuperMusa1998
    @SuperMusa1998 7 ปีที่แล้ว

    thanks

  • @caffeineiv4335
    @caffeineiv4335 9 ปีที่แล้ว

    And round 3. 2e^x + 4e^2x + xe^2x minimum passing score, here we come! Thank you

  • @marihuano69
    @marihuano69 14 ปีที่แล้ว

    i need your help man, look at this: (2s-1)/s^2(s+1)^3 i know the answer (A=5, B=-1, c=-5, D=-4, E=-3) but im only able to get B and E cos the other letters are multiplied by S^2(s+1)^3 , thx in advance!

  • @samibraheem2333
    @samibraheem2333 9 ปีที่แล้ว +1

    I'm in LOVE WITH YOU!!!

  • @nkhlgeorge
    @nkhlgeorge 14 ปีที่แล้ว

    hey could u pls convert this term into partial fractions for me-
    1/[r(r+1)(r+2)(r+3)]

  • @alidostan
    @alidostan 14 ปีที่แล้ว

    you r just greeeeeeeeeeeeeeat sal :)

  • @kingmurillo
    @kingmurillo 14 ปีที่แล้ว

    O.o
    thanks! :D

  • @Daski69
    @Daski69 9 ปีที่แล้ว

    the fact that it's C/(x-2)^2 makes perfect sense, but couldn't you also put
    A/x-1 + Bx+C/(x-2)^2
    in that case you'd still have a 1st degree over a 2nd degree, right?
    thanks!!!
    ...and all hail the Great Khan

    • @mawahebbadawi3819
      @mawahebbadawi3819 9 ปีที่แล้ว

      for you to put bx+c as your numerator your denominator has to be , 1. not factorise and 2. not factorisable

  • @bwibwi5
    @bwibwi5 9 ปีที่แล้ว +7

    My head. It hurts.

  • @neetumishra2632
    @neetumishra2632 8 ปีที่แล้ว

    what if we had (x-2)^3 in the denominator

    • @idknuttin
      @idknuttin 8 ปีที่แล้ว +1

      watch the end of the video, he explains it

  • @Daski69
    @Daski69 9 ปีที่แล้ว

    couldn't you write the denominator as (x-1)(x^2-4x+4) and just do (A)/(x-1) + (Bx+C)/(x^2-4x+4) ???
    i get why he did it the way he did but I fail to see how the way above is inconsistent... it gives the wrong answer

  • @rockandrollkevin
    @rockandrollkevin 13 ปีที่แล้ว +1

    My intuition is a bit hairy, Sal.

  • @anonymous-pb2fc
    @anonymous-pb2fc 9 ปีที่แล้ว

    I will now tell you a magic trick, at around 5:34 or 5:45 when he takes the value of x to be (1)one there instead of 1 take the value to be 2 and instantly all your variables will be canceled out !!!!!

    • @niceandwise1474
      @niceandwise1474 8 ปีที่แล้ว +1

      +Yusra Sohail i think you can use the constant two at that time and nothing will be changed .

  • @anjalbinayak
    @anjalbinayak 3 ปีที่แล้ว

    How many people are watching it on February 2021?

  • @rosep4424
    @rosep4424 7 ปีที่แล้ว

    Why is x set to 0 ?

    • @sleepilatanja
      @sleepilatanja 6 ปีที่แล้ว +1

      RoseLilly Channel he just thought it was easier to do with zero, you can literally use any number. :)

  • @abeeramir6006
    @abeeramir6006 7 ปีที่แล้ว

    (x^3+2x+2)÷(x^2+x+1)^2
    how to begin that one???

    • @magnuschanduru6173
      @magnuschanduru6173 4 ปีที่แล้ว

      Use binomial thrm at the bottom and u will get the degree as 4 😝🤭, but still solvable

  • @mrhappy192
    @mrhappy192 7 ปีที่แล้ว +3

    10th letter is J :D

  • @valentinbeleca6096
    @valentinbeleca6096 7 ปีที่แล้ว

    this guy...so funny

  • @junkyarddog723
    @junkyarddog723 4 ปีที่แล้ว

    What!! 2009!!!😲

  • @paulceltics
    @paulceltics 13 ปีที่แล้ว

    no dislikes :)

  • @cinquain0
    @cinquain0 5 ปีที่แล้ว

    I don’t know how you turned that ugly equation into something pretty

  • @MrTakeUrBitch95
    @MrTakeUrBitch95 12 ปีที่แล้ว

    fucking genius

  • @AnaVazquez428
    @AnaVazquez428 12 ปีที่แล้ว

    Oh hush, get your head out of the gutter :)

  • @td-po5ik
    @td-po5ik 11 ปีที่แล้ว

    thanks for this !

  • @doublelunch24
    @doublelunch24 9 ปีที่แล้ว

    Thanks, Sal!