Finding The Zeros of Fourth Degree Polynomial

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  • čas přidán 23. 10. 2011
  • 👉 Learn how to find all the zeros of a polynomial by grouping. 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 by grouping, we first equate the polynomial to 0 and then use our knowledge of factoring by grouping to factor the polynomial. Next, we 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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    👨‍👩‍👧‍👧 About Me: I make short, to-the-point online math tutorials. I struggled with math growing up and have been able to use those experiences to help students improve in math through practical applications and tips. Find more here: www.freemathvideos.com/about-me/
    #polynomials #brianmclogan

Komentáře • 222

  • @brianmclogan
    @brianmclogan  Před 12 lety +80

    glad I could help, its fun when those things finally start to make sense

    • @iftikharshamsniloy8579
      @iftikharshamsniloy8579 Před 3 lety +3

      Thanks a lot ,sir. I really appreciate your effort ! You helped me a lot. May Allah bless you.

  • @liankhai6019
    @liankhai6019 Před 7 lety +241

    LOL my math teacher is too lazy to teach so she told us to watch this video

  • @Bigschmitt25
    @Bigschmitt25 Před 8 lety +46

    Thank you this helped a lot! I also love how you dont even edit out you calling out your student for not paying attention. I was laughing my ass off at that.

    • @brianmclogan
      @brianmclogan  Před 8 lety +14

      +Nick Meme you are welcome! yep it's the real deal, life in my classroom

  • @brianmclogan
    @brianmclogan  Před 11 lety +55

    I don't know why I said you couldn't factor by grouping for this problem. You certainly could. I think I was more concerned with showing how to solve using rational zeros

  • @bksupply8186
    @bksupply8186 Před 5 lety +28

    So lucky i found this channel

  • @brianmclogan
    @brianmclogan  Před 11 lety +21

    I appreciate your kind words

  • @Riverbend1752
    @Riverbend1752 Před 3 lety +26

    I'm a sophomore in college, and the professor teaching my differential equations course linked this video in our study materials. Thanks for putting it out there. It had been so long since I took an algebra class that I had forgotten how to do this, but this was a really approachable way to relearn it.

    • @IRON_KING_KNIGHT
      @IRON_KING_KNIGHT Před 2 lety +1

      I’m going through the same thing in differential equations as well 🤣🤣🤣

    • @she8334
      @she8334 Před rokem

      Are we living the same life? a sophomore too, and I am here because of my differential equations course

    • @souryour6598
      @souryour6598 Před 4 měsíci

      You learn this in collage, im learning it in year 9

    • @Riverbend1752
      @Riverbend1752 Před 4 měsíci

      @@souryour6598 I hope you are also studying English. One does not study at collage; they study at college.

  • @deedeeOWL
    @deedeeOWL Před 5 lety +13

    👍🏼 I like how the teacher have include all zeros (even the imaginaries) so students see the big picture, and think in terms of Complex: Real and Imaginaries

  • @khushibarnawal9271
    @khushibarnawal9271 Před 5 lety +22

    Sir your videos are easy to understand... I wish I could study with you in my school.

    • @brianmclogan
      @brianmclogan  Před 5 lety +8

      happy they help, visit them whenever you neeed

  • @1v1noscope37
    @1v1noscope37 Před 4 lety +6

    Was going crazy trying to figure out how to factor these, appreciate the help 💪

  • @asystoleD
    @asystoleD Před 7 lety +96

    0:45 LMFAO

  • @mt33205
    @mt33205 Před 4 lety +3

    I'm taking engineering and watching this guys vids for finals, really shouldn't have skipped so many lectures...

  • @Starscrayper
    @Starscrayper Před 7 lety +1

    With your help, I'm able to cram for my college algebra test, and I am infinitely grateful for this.

  • @fedorshcheglov5534
    @fedorshcheglov5534 Před 4 lety +3

    Watching this during quarantine, very helpful when you can't reach your teacher! :)

  • @those.gamers.
    @those.gamers. Před 5 lety +14

    ah thank you, my math teacher expected us to do a packet with a question like this and didn’t teach it lol

  • @kmillz7414
    @kmillz7414 Před 11 měsíci +1

    Brian, your videos continue to help me everyday. Thank you for doing what you do...and please continue to do so.

  • @aliris19
    @aliris19 Před 8 lety

    I'm a parent struggling to explain "CC" math to my kid and wow do I appreciate your videos. Thank you!!!

    • @brianmclogan
      @brianmclogan  Před 8 lety

      +Sara Roos you are very welcome! happy my videos are helping!

  • @yzel36
    @yzel36 Před 3 lety +1

    Your channel is a life saver thank goodness I found these videos

  • @livfrazier6295
    @livfrazier6295 Před 8 lety +2

    Wow, this was explained so well. THANK YOU!

  • @FreeDomSy-nk9ue
    @FreeDomSy-nk9ue Před 6 lety +1

    The trick you mentioned about the constant is just amazing

  • @jesuisravi
    @jesuisravi Před 5 lety

    Question: What do you call the course you are teaching here? Is it Algebra 2 or precalculus or what?

  • @gsbedi68
    @gsbedi68 Před 4 lety

    Wow !! Thank you for the help sir!! You were amazing !!

  • @Hahaalot
    @Hahaalot Před 7 lety

    Yo my nigha! Literally in college Algebra and used this video for my homework. Completely forgot parts because of spring break. U's the real MVP! Thanks my guy! :)

  • @sohamparekh
    @sohamparekh Před 4 lety

    Very helpful, thank you.

  • @mammamia151
    @mammamia151 Před 3 lety

    Thank you so much for helping me with my math homework!

  • @kelaahmetaj785
    @kelaahmetaj785 Před 5 lety

    Your video was helpful for me, but I wanted to ask you about sth: how did z+1 came out as a factor. The other factor is taken by the coefficients we take by the synthetic division, but I wanted to know more about the first one

  • @thomasjones145
    @thomasjones145 Před 4 lety

    Thank you, this helped me so much!

  • @annhashi1768
    @annhashi1768 Před 5 lety +1

    Thank you sir it really helped me .

  • @Historyhappenshere
    @Historyhappenshere Před 2 lety

    Brian is saving my life right about now

  • @nonokay20
    @nonokay20 Před 11 lety

    You are a great teacher!!!!

  • @darrelseibert420
    @darrelseibert420 Před 9 lety

    one hell of a video thanks for clearing up the whole if it isn't to at least the 2nd power it is a 0 thing. also i am glad to see a thorough explanation to your work. For example, my teacher never really elaborated with the remainders in synthetic division and I had no clue what it meant. Wish me luck on my quiz tomorrow.

    • @brianmclogan
      @brianmclogan  Před 9 lety

      Darrel Seibert Good Luck! keep up the hard work and let me know how you do

  • @postbarone
    @postbarone Před 7 lety +9

    what if you can't factor it?
    also, what (in your opinion) is the most difficult thing about pre-calc after finishing algebra2?
    I'm taking a pre-calc final without having taken the class because I want to skip the class and go straight to ap calc. I heard most of pre-calc is basically algebra2, therefore I need to know what new things I need to learn. any advice you would give me? thanks

    • @brianmclogan
      @brianmclogan  Před 7 lety +3

      I think if you knew these three chapters really well you would do fine in calc. Trig, you have to know your trig, rational function, you need to know rational functions, logarithms, especially natural logarithms and exponential. You are correct that most of Pre-Calc is Algebra 2 but it also serves another purpose and goes deeper than Algebra 2. If you feel comfortable in your math skills and are willing to work hard in Calc you can do it. However for a lot of people taking an extra year to focus on Pre-calculus skills is necessary to be successful in Calc. It might be helpful to speak with your Algebra 2, Pre-Calc, and Calc teacher for their advice as well as to maybe give you an assessment to see where you stand

    • @postbarone
      @postbarone Před 7 lety +2

      Brian McLogan ok thank you! I'll be taking an assessment in a couple of days and if I pass I can go to ap calc next year. Also what in your opinion are the best ways to study this?

  • @jerryfan8378
    @jerryfan8378 Před 4 lety +4

    At 8:46 shouldn't it be i*sqrt of 2? This way, when you put "i" in the equation, it will change sqrt of -2.

  • @remytherat2175
    @remytherat2175 Před 4 lety +1

    THIS SAVED ME THANK YOUUU

  • @ansenliu
    @ansenliu Před 3 lety

    Thank you so much, you're a good man, you deserve honor :)

  • @brianmclogan
    @brianmclogan  Před 11 lety +3

    When graphing this polynomial see that there are no real roots. Meaning their are no real zeros you can solve for(x-intercepts)

    • @MPV2023
      @MPV2023 Před 6 lety

      Brian McLogan ...can u find me the roots for below eq'n...
      s^4+12s^3+91s^2+150s+50....???

  • @paulinjosepha2336
    @paulinjosepha2336 Před 7 lety

    Good Job Professor and thank you so much for this video. I have Mid-term of Math 34 differential equation on the Wednesday , i was struggle to understand this part . However your video give me 10 points already. Again, thank you so very much.

  • @heystobit2608
    @heystobit2608 Před 5 lety

    Sir, can we use another method other than factorization.

  • @jonathanjohnson7508
    @jonathanjohnson7508 Před 9 lety +1

    What would you do if there were no rational zeroes for a polynomial to the fourth degree? I know it'd require imaginary numbers, but I don't know how to factor it and get a+bi

  • @user-om3vf1qf2d
    @user-om3vf1qf2d Před 6 měsíci

    Can i ask what grade u teach it's very helpful

  • @ganeshnithiyananthan8487

    thanks for these videos really helped a lot for my exams

  • @Jakomaniac1
    @Jakomaniac1 Před 3 lety

    Bless your soul

  • @proshidhhajong9914
    @proshidhhajong9914 Před 7 lety

    Thank you Sir it was really helpful!

  • @Orcrin12
    @Orcrin12 Před 6 lety

    So say you have access to a graphing calculator, how do you determine the imaginary zeros? Can you do it using the graph or do you have to use rational zero test and factoring?

    • @brianmclogan
      @brianmclogan  Před 6 lety +1

      graphing calculator is not going to help you with the imaginary, that will come from factoring down your remaining factors

  • @900q8
    @900q8 Před rokem +1

    tysm this helped a lot!

  • @RzVids
    @RzVids Před 7 lety

    You'd divide P/q and use that answer for synthetic division? That's if 1 and -1 doesn't work.
    So (in the same problem), you could try 4 and -4? 2 and -2?
    Does the Rational Zero test always work?
    What if you couldn't factor by grouping and if you didn't have another factor?

    • @brianmclogan
      @brianmclogan  Před 7 lety

      best bet is to graph the polynomial to find the zeros and go from there, however if you are not allowed a graphing calculator then yes Rational zero test will give you every zero that is rational. Only problem is you don't know which one till you test them

  • @harrisonbennett7122
    @harrisonbennett7122 Před 5 lety

    Thank you

  • @ShivaPrasad-hm5lk
    @ShivaPrasad-hm5lk Před 6 lety

    superb excellent.......... I liked ur explanation continue

  • @cadmiumbop
    @cadmiumbop Před 5 lety

    so for that polynomial there is only 3 roots even though it is an x^4 polynomial? is it something to do with the fact that there is no x^2

  • @wexer82
    @wexer82 Před 8 lety

    Thank you.

    • @brianmclogan
      @brianmclogan  Před 8 lety +1

      +wexer82 you are very welcome! happy to help

  • @marymccory8075
    @marymccory8075 Před 8 lety

    Great!!!!! I should have came here for help a long time ago!!!!!

  • @jlitt
    @jlitt Před 5 lety

    You are an angel

  • @dailycam9579
    @dailycam9579 Před 3 lety

    Sir you are the best

  • @sethlangendoen1313
    @sethlangendoen1313 Před 3 lety

    All he said was "factor by grouping" in the beginning and I could solve my question.

  • @adarshkumar6231
    @adarshkumar6231 Před 6 lety +3

    Omg nice!!

  • @ASTROvalo
    @ASTROvalo Před 6 lety +1

    Awesome

  • @monicamedina3838
    @monicamedina3838 Před 5 lety +2

    I Need Your Help !! You Are Very Good At Teaching !! Can you Help Me With This Problem !! Please x^5+7x^3-x^2+4x-21!! It's A Problem on My Homework and It Says to Determine The Number of Roots that Each Polynomial will have. I Don't Understand It !! Please Get Back To Me.

  • @ipihu
    @ipihu Před 3 lety

    Thanks you helped a lot I want tutions from you if you can plz

  • @bluekai3317
    @bluekai3317 Před 3 lety +2

    this make me feel like im in actual class tho it's online class now bc of corona

  • @aadamrayanbinabu
    @aadamrayanbinabu Před 7 lety

    the polynomial x^5+ax^4+3x^3+bx^2+a where a and b are constant has a factor (x-2)^2 using the factor theorem and the result of part (i) otherwise find the value of a and b.

    • @brianmclogan
      @brianmclogan  Před 7 lety +1

      sorry I do not have time to work on extra problems for students as I receive multiple requests

  • @oskarlindelof9685
    @oskarlindelof9685 Před 7 lety +1

    I solved it using factoring, this is how I did:
    z^4-4=(z^2+2)(z^2-2)
    -z^3-2z=-z(z^2+2)
    z^4 -z^3-2z-4=(z^2+2)(z^2-2)-z(z^2+2)=(z^2+2)(z^2-2-z)
    z^2-z-2=0 or z^2+2=0. Using the quadratic formula you can then determine that the roots are -1, 2 and +/-sqrt(2)i.

  • @kumarshrey5206
    @kumarshrey5206 Před 6 lety

    Thank you sir .....do u have any trick to solve using differiation calculus...plz reply...From india

    • @brianmclogan
      @brianmclogan  Před 6 lety

      I have plenty of videos on that, not tricks but examples

  • @legendneverdiegaminglndg4136

    Sir can you tell me who was the student ?

  • @kushalchakrabarti240
    @kushalchakrabarti240 Před 5 lety

    Sir.. big fan!

  • @prathameshvarma4999
    @prathameshvarma4999 Před 7 lety +1

    Helped me a lot... Thanks!!

  • @ghazishaaban5253
    @ghazishaaban5253 Před 6 lety

    very good teacher

  • @boywonder_YT
    @boywonder_YT Před 2 lety +1

    Tristen, you really gotta listen buddy.

  • @gr8tmeg
    @gr8tmeg Před 11 lety

    why in the beginging couldn't do you factor by grouping? you could group z^4 and z^3 together, and -2z and -4

  • @rolandpoland5363
    @rolandpoland5363 Před 3 lety

    Helped me pass too many Alg 2 tests

  • @Remarkpeace
    @Remarkpeace Před dnem

    Thank you isn't enough!

  • @lanyahunar2659
    @lanyahunar2659 Před 2 lety

    What if you tried all number and not equal to 0 to factor it?? please answer

  • @eunicedickson9526
    @eunicedickson9526 Před 6 měsíci

    What if this method also doesn't work for me? I'm solving x^4 + 2x^2 - x - 3 = 0. Any help please?

  • @to0ot512
    @to0ot512 Před 7 lety

    why did u use -1 ?
    I tried to use you way at this polynomial and I couldn't make it
    find the zeros : x^3-7x^2+7x+15
    how can u solve it by using the possible rational zeros ? and thank u so much

    • @brianmclogan
      @brianmclogan  Před 7 lety

      I would not use the rational zero test, I would graph it on my calculator or google to determine one rational zero, then use synthetic division to find the rest. -1, 3, and 5 look good

  • @JLvatron
    @JLvatron Před 2 lety +1

    Great explanation! And who are the fools at 0:42 disturbing class!!

  • @Samsam_149
    @Samsam_149 Před 3 lety

    ur a god dude thank you so much

  • @dallasbakerfollowthecode

    Hey im taking college algebra and I havnt taken a math class sense junior year of highschool and I remember this but im not understanding how you went from a x^3 to a square?

  • @bustinbinden
    @bustinbinden Před 3 lety

    that chinstrap was STRONG

  • @neil6257
    @neil6257 Před 7 lety +59

    triggered

    • @brianmclogan
      @brianmclogan  Před 7 lety +26

      ?

    • @RzVids
      @RzVids Před 7 lety +28

      Brian McLogan hahaha, he meant that the student wasn't paying attention and you got peeved about it, thus you were "triggered".

  • @shravanikharkar4687
    @shravanikharkar4687 Před 3 lety

    My teacher suggest me this channel To better understand 😊

  • @musicisthefoodofthesoul

    Super

  • @Its_A_Dulla
    @Its_A_Dulla Před rokem +1

    Why is the q ±1?

  • @splabicado6510
    @splabicado6510 Před 3 lety

    my teacher always told us that the degree of the polynomial is the amount of solutions it has, but here you only got 3 solutions for a degree 4 polynomial, whats up with that?

  • @danpost5651
    @danpost5651 Před 4 lety +1

    In nine years, did no one catch your error that sqrt(-2) is not +-sqrt(2i), but +-sqrt(2)*i ? It appeared to me that (the wrong one) is what you wrote on the board twice.

  • @VardhanAditya
    @VardhanAditya Před 5 lety +2

    can you solve m^3 -3m^2 -4m +8

    • @pgbrandon
      @pgbrandon Před 2 lety

      Any luck? I was trying to solve the same one;)

  • @meownamejeff
    @meownamejeff Před 5 lety +6

    says "q" writes "8"

  • @ghorg1337
    @ghorg1337 Před 10 lety

    im only in first year of highschool and this might be a stupid question but when u set z^3-2z^2+2z-4 where do u get the -2 in -2z^2 from i understand the rest of it but i cant see where u get that

    • @brianmclogan
      @brianmclogan  Před 10 lety

      I don't see the -2

    • @ghorg1337
      @ghorg1337 Před 10 lety

      OriGinal Bosnian i looked it up now and i saw that u dont have the same school categorys as we do and translated to ur school system im in 3rd year of highschool but in our system its first of a 3 year school the first year after like basic school

    • @ghorg1337
      @ghorg1337 Před 10 lety

      Mr. McLogan's Math Channel i understood why u put -2 now at 6:16 its becasue of the polynoma system thing

    • @brianmclogan
      @brianmclogan  Před 10 lety

      okay good, glad you were able to have it straighten out

  • @rababbouali4023
    @rababbouali4023 Před 4 lety

    Can you find the zeroe of. 2x⁴-9x³+8x²-9x+2

  • @xbz3795
    @xbz3795 Před 3 lety

    what math level is this? algebra 2?

  • @nathanselman.realtor
    @nathanselman.realtor Před 6 lety

    What do you do if your "q" doesn't equal 1?

  • @dash15yearsago67
    @dash15yearsago67 Před 3 lety

    6:17 wouldn't we have to use rational root theorem again?

  • @gurpreetbhullar2540
    @gurpreetbhullar2540 Před 6 lety

    Pls make a video on. Eight power equation

    • @brianmclogan
      @brianmclogan  Před 6 lety

      that does not seem very fun, the same process would apply but there would be 8 zeros so a bit of work

    • @gurpreetbhullar2540
      @gurpreetbhullar2540 Před 6 lety

      Brian McLogan sir I am unable to solve eight power equations do you know how to solve them. Pls help me it will great help sir

    • @gurpreetbhullar2540
      @gurpreetbhullar2540 Před 6 lety

      I have four equations on eight power which I am unable to solve pls guide me sir

  • @huankoi3403
    @huankoi3403 Před 2 lety +1

    i'm from vietnam and it's very simple here

  • @-clipz-
    @-clipz- Před 8 měsíci

    God bless agtg

  • @gerhardvanniekerk3759
    @gerhardvanniekerk3759 Před 7 lety

    Pleas do -20x to the power of 4 + 5x to the power of 3 +17x to the power of 2 -129x +87 = 0

    • @brianmclogan
      @brianmclogan  Před 7 lety +1

      sorry only have time to work problems for my classes

  • @imranali-iy5wk
    @imranali-iy5wk Před 6 lety

    please make video on probability

    • @brianmclogan
      @brianmclogan  Před 6 lety

      I only have a couple videos, here is the playlist czcams.com/play/PL0G-Nd0V5ZMqm0bjCCiqbTCXQ2OzU2fqy.html

  • @Maharshigurukultrader
    @Maharshigurukultrader Před 6 lety

    (X-1)^4 + (x-5)^4 = 82 how solve it?

  • @fahadimran6961
    @fahadimran6961 Před 6 lety +1

    Sir how to solve x^4+x^3=0

  • @steamline432
    @steamline432 Před 10 měsíci

    Awesome video, very helpful, but I spent an unholy amount of time trying to figure out why he said "q", then wrote an 8. I'm pretty dumb sometimes.

  • @sketchers7331
    @sketchers7331 Před 6 lety

    where are you from

  • @devan7485
    @devan7485 Před 2 lety +1

    take in these kids are like 30 years old now