09 - The Quadratic Formula Explained, Part 1 (Practice Problems & Solutions)

View more lessons at www.MathAndScience.com.
In this lesson, you will learn what the quadratic formula is, how to use it, and why it is important to solve quadratic equations in algebra.
First, we will derive the quadratic formula using the completing the square method. Next, we will solve numerous quadratic equations using the quadratic formula and check the answers.

Пікірлер: 128

  • @vuyisekaluphuzi8249
    @vuyisekaluphuzi82492 жыл бұрын

    Nobody else on KZread teaches the way you do. When I'm failing to undsomething I just come to your channel and you always make me understand

  • @emmyikande7492

    @emmyikande7492

    Жыл бұрын

    very true

  • @juliel6023
    @juliel60233 жыл бұрын

    My college classes have youtube videos and they can't come CLOSE to explaining it as well as you can. I always come straight to you for explanations and it has helped me so much! THANK YOU!

  • @user-pp6gp6zb2k
    @user-pp6gp6zb2k8 ай бұрын

    I always enjoy this style

  • @jonnukisan9759
    @jonnukisan97592 жыл бұрын

    Now I'm glad that I learned completing the square before learning the quadratic formula! You made it so clear how they are derived. Thank you, great punch line

  • @Sc19869
    @Sc198692 жыл бұрын

    You sir have thought me so much, I’m 35 and studying for my ged. Thank you for your easy to learn videos.

  • @lauraoergel6003

    @lauraoergel6003

    Жыл бұрын

    That is so awesome, Saul!!! You can do this!

  • @Sc19869

    @Sc19869

    Жыл бұрын

    @@lauraoergel6003 thank you. I passed the math test 2 months ago.

  • @akramshaheen2481

    @akramshaheen2481

    Жыл бұрын

    Bro your 35 and studying quadratic formula I'm 14

  • @ESTAAAAAA

    @ESTAAAAAA

    Жыл бұрын

    @@akramshaheen2481 what a big boy you are

  • @YourWrongImRight933

    @YourWrongImRight933

    Жыл бұрын

    @@akramshaheen2481 bro you’re 14 studying quadratic formula im in 7th grade

  • @eddyvilla-wz4zd
    @eddyvilla-wz4zd10 ай бұрын

    You're one of the best math coches on youtube.

  • @user-xw3do9lp9x
    @user-xw3do9lp9x3 ай бұрын

    You are the best teachers at first I don't understand this topic but through your slow explanations I understood ❤

  • @user-ed7ko8og2i
    @user-ed7ko8og2i8 ай бұрын

    I love your teaching; well analysed.

  • @sadhanghosh7721
    @sadhanghosh77212 ай бұрын

    Wow!!, Sir, your intelligence & technic of taught is no doubt claimant of praise. Really, really, really it's adorable. Many, many thanks, Professor.

  • @rommelzambrano7799
    @rommelzambrano77993 жыл бұрын

    What a great tutor you are, you make that real understandable. Thanks, greetings from Cali, Colombia.

  • @carolhill9934
    @carolhill99345 күн бұрын

    Still watching still learning. You are the best!

  • @user-yc6rd5pq9e
    @user-yc6rd5pq9e Жыл бұрын

    Wow learning it today hours before my exam thanks a lot 🤗really helped

  • @damon123jones
    @damon123jones3 жыл бұрын

    i love your style, best teacher on a subject i have always been sble to do but never really understood

  • @littlesunshine0
    @littlesunshine0 Жыл бұрын

    I'm Brazilian and I loved your class!

  • @smendetv1105
    @smendetv11054 жыл бұрын

    A blow by blow account of the derivation...much better clear as daylight

  • @MathAndScience

    @MathAndScience

    4 жыл бұрын

    Awesome!

  • @RahulThakur-ok4zv
    @RahulThakur-ok4zv2 ай бұрын

    Sir you are the living legend ❤

  • @lzyong306
    @lzyong3068 ай бұрын

    Best explanation ever

  • @zhengzhang3903
    @zhengzhang390311 ай бұрын

    One thing I would like to mention is that 15:33 if a is negative, and you take the square root of 4a^2 you can get -2a. But since there is a plus or minus sign in the front, it does not change the form.

  • @jevonjohnson5797
    @jevonjohnson57972 ай бұрын

    Man you understand everything.....thanks for sharing been following ur chem and physics also

  • @cyrusgitonga7984
    @cyrusgitonga798411 ай бұрын

    12:12 is reassuring. That even the best of the best would be losing sight of the tail end of this thing they are unravelling if they look aside even for a brief moment

  • @zacharycavalear2643
    @zacharycavalear26433 жыл бұрын

    Thank you for every video you decide to do! Your explain everything I always have questions on coming from textbook teachings! Hands down best teacher I’ve found

  • @scottpuk-wq9dq
    @scottpuk-wq9dq Жыл бұрын

    I really love your teaching i understand every thing clearly..thanks so much

  • @majorynambeye3943
    @majorynambeye39432 жыл бұрын

    You are best. You really explain the work very well. Thanks for making me understand how the quadratic formula is derived.

  • @Tramicful
    @Tramicful Жыл бұрын

    Amazing, you are my saviour, great presentation, educational and entertaining!

  • @Shoreline4Iron
    @Shoreline4Iron2 жыл бұрын

    Thank you. I enjoy learning from you.

  • @MP-yo2fx
    @MP-yo2fx2 жыл бұрын

    Again you are saving my life!! You are truly the best

  • @hollyhowarth3415
    @hollyhowarth3415 Жыл бұрын

    You are a great teacher, you make things make so much sense. I love how you set up the lesson with objectives and explain why things are the way they are. Thank you so much

  • @MathAndScience

    @MathAndScience

    Жыл бұрын

    You're very welcome!

  • @jonwill
    @jonwill2 жыл бұрын

    Excellent presentation; thank you for sharing.

  • @farohakhan6767
    @farohakhan67672 ай бұрын

    Welldone 🎉

  • @chigazuibe9943
    @chigazuibe9943 Жыл бұрын

    I love all teachings and also it's very easy to understand

  • @shawnd.8498
    @shawnd.84982 жыл бұрын

    You saved the day for me, sir!

  • @emmanuelwilson902
    @emmanuelwilson9023 жыл бұрын

    Good work out,am grateful

  • @learnersupdate
    @learnersupdate Жыл бұрын

    Nice and detailed, Simple!

  • @mirvetloli1309
    @mirvetloli13095 ай бұрын

    thats was amazing thank you about the intresting lesson

  • @sallaklamhayyen9876
    @sallaklamhayyen98763 жыл бұрын

    perfect thank you

  • @elijahbanda7989
    @elijahbanda79892 жыл бұрын

    You are the best hoping to see more maths videos 👏👏👏👏 thanks sir I now memorise the method like writing my name

  • @rubiegamble898
    @rubiegamble898 Жыл бұрын

    I'm trying to get my GED and I need to learn the Quadrtic Formula.

  • @emmyikande7492
    @emmyikande7492 Жыл бұрын

    God bless you sir i have downloaded lots of your videos and i must commend you for a job well done. kudos🥰

  • @clementmichaelc2876
    @clementmichaelc28763 жыл бұрын

    This is very helpful

  • @tresajessygeorge210
    @tresajessygeorge2105 ай бұрын

    THANK YOU... SIR...!!!

  • @ursulagwozdz1955
    @ursulagwozdz19552 жыл бұрын

    Brilliant!

  • @charityliwewe9711
    @charityliwewe97112 жыл бұрын

    U've made it easier just like A,B,C,D 👏 👏

  • @robertlawrence2490
    @robertlawrence249011 ай бұрын

    Hi, I have taught high school and college math for over 30 years. I always learn some tips from watching your lessons. Do you teach calculus? Robert

  • @stanphiri2341
    @stanphiri23413 жыл бұрын

    Amazing

  • @IM-nb8rk
    @IM-nb8rkКүн бұрын

    Great vid!

  • @likesmusic11
    @likesmusic11 Жыл бұрын

    This professor is no joke!!!!!! My professor works the problem, but does not go into detail as he does.

  • @guidofeliz8384
    @guidofeliz83845 жыл бұрын

    Can you prove the quadratic formula? Jason, here is an idea for you. Why not make videos in terms of math proofs? I am sure that math majors would love you for it.

  • @sandrarr5434
    @sandrarr5434 Жыл бұрын

    Hello there I'm studying the AQA foundation and I wondered if you could tell me how does one know when to apply the Elimination process t o simultaneous equation and when to apply substitution what is the distinctive different that I should know please.? Is it when there's an X Square coefficient

  • @exotickhanaarif4333
    @exotickhanaarif43332 жыл бұрын

    Amazing simply amazing

  • @fathoy1
    @fathoy13 жыл бұрын

    Thank you so much

  • @lauren9004
    @lauren90046 ай бұрын

    Thank you!

  • @carolinelewis952
    @carolinelewis952 Жыл бұрын

    Please tell me about the i. I'm jus learning all this.

  • @sawdustwoodchips
    @sawdustwoodchipsАй бұрын

    Completing the square allows you to find the turning point of the quadratic.

  • @carlos_so_nice9064
    @carlos_so_nice90642 жыл бұрын

    This was very helpful

  • @eenayeah
    @eenayeah Жыл бұрын

    Phenomenal!

  • @Yesmayo1982
    @Yesmayo19823 жыл бұрын

    why is b/ax divided by 2 then squared? WHy not do the same with x squared and -c/a?

  • @Tamilore831
    @Tamilore8317 күн бұрын

    Thanks teacher ❤

  • @haykghukasyan6555
    @haykghukasyan6555 Жыл бұрын

    Thanks you very much

  • @user-yn3ev1oy1j
    @user-yn3ev1oy1j10 ай бұрын

    At 7:58 why do you have to divided by 2 and square root answer please I need really help please I hope you reply.

  • @hamzatayomide2482
    @hamzatayomide2482 Жыл бұрын

    I would like to see more of this

  • @user-yn3ev1oy1j
    @user-yn3ev1oy1j10 ай бұрын

    At 7:58 why do you have to divided by 2 and square root it pleases response I hope you see it

  • @ebrimagaye-nd1ru
    @ebrimagaye-nd1ru Жыл бұрын

    I like the way you teach

  • @iqrahashi8633
    @iqrahashi86333 жыл бұрын

    Thanks

  • @sureshidu3119
    @sureshidu3119 Жыл бұрын

    Very nice 👍👍👍👍

  • @MabvutoMilambo-xe3hk
    @MabvutoMilambo-xe3hk Жыл бұрын

    Nice 👍

  • @ritam20071
    @ritam20071 Жыл бұрын

    This method is called Sridharacharaya method discovered in 10th century AD by Indian mathemetician

  • @vaibhavsingh8361
    @vaibhavsingh83612 жыл бұрын

    Quadratic Formula is Known as Sri Dharacharya Fomula Which is Derived from Indian Mathematician

  • @jonnukisan9759
    @jonnukisan97592 жыл бұрын

    an endless accordion of whiteboards! awesome

  • @worknehgebeyehu9598
    @worknehgebeyehu9598 Жыл бұрын

    Thank you teacher

  • @MathAndScience

    @MathAndScience

    Жыл бұрын

    You are welcome

  • @johnmaulkin-ur8lm
    @johnmaulkin-ur8lm11 ай бұрын

    Fantastic job but i am confused; at 13.19 mins. b/2a.x + b/2a.x = b/a.2x. Please help. Thank you.

  • @ChavoMysterio
    @ChavoMysterio3 жыл бұрын

    Here's a fun fact about me: I first learned about the quadratic formula in Geometry.

  • @TheByzmal
    @TheByzmal Жыл бұрын

    (Ques) I 15 min & 35 secs. Why did you square root the denominator & not the numerator.? You only square root 4ac^2 & not the terms above it. Why?

  • @MathAndScience

    @MathAndScience

    Жыл бұрын

    I did take the square root of the bottom. The answer was 2a.

  • @TheByzmal

    @TheByzmal

    Жыл бұрын

    @@MathAndScience I see & know that, I am asking about the top. Why didn't b^2 - 4ac became b - 2ac?

  • @theophonchana5025
    @theophonchana50252 жыл бұрын

    b^(2) - 4ac = 13

  • @ownagebox
    @ownagebox5 ай бұрын

    at my time we only learnd the pq-formula

  • @theophonchana5025
    @theophonchana50252 жыл бұрын

    b^(2) - 4ac = -36

  • @theophonchana5025
    @theophonchana50252 жыл бұрын

    b^(2) - 4ac = 20

  • @stevenscottoddballz
    @stevenscottoddballz3 жыл бұрын

    3:52 I keep hearing "Always get 2 solutions", but when I did [3A² = 6A - 3], there was only ONE solution.

  • @jozef-aerts-wiskunde

    @jozef-aerts-wiskunde

    2 жыл бұрын

    You have 2 , 1 or 0 solutions , depending on the value of d^2 -4ac ( called discriminant )

  • @stevenscottoddballz

    @stevenscottoddballz

    2 жыл бұрын

    @@jozef-aerts-wiskunde I am VERY familiar with the discriminant. I have had trouble with [S² + 7/4 = 1/2]. I don't know what to do with the 2 in the discriminant.

  • @Koreanbosuji
    @Koreanbosuji3 жыл бұрын

    If you are here and wondering WHO IS THIS TEACHER EXTRAORDINAIRE?! (Well I DID at least.) I have watched innumerable wonderful math videos for my child, some very helpful some hardly, BUT NONE had a speaker and explainer who cut through all the fine planes and invisible obstacles which trip up a thorough understanding of the topic at hand. He's Mr Jason Gibson. And VOILA .. why am I not surprise anymore that he's SO DAMN GOOD?! Read on ( Found from the link to his website :www.mathtutordvd.com ) He has : - Bachelor's in Electrical Engineering - Master in Electrical Engineering AND Physics Is a : - Former NASA Space Shuttle Mission Controller - Rocket Scientist for NASA Plasma Propulsion And why is he doing these videos?? Well "He has a Passion for Teaching and Making Complex Topics Simple to Understand!!!"

  • @Koreanbosuji

    @Koreanbosuji

    3 жыл бұрын

    @Jason Gibson

  • @MathAndScience

    @MathAndScience

    3 жыл бұрын

    Thank you so very much! I really appreciate the kind words!

  • @Koreanbosuji

    @Koreanbosuji

    3 жыл бұрын

    @@MathAndScience :-D Anytime - welcome

  • @apoll0626
    @apoll0626 Жыл бұрын

    why do you prime factorise

  • @Ihuoma307
    @Ihuoma307 Жыл бұрын

    Waw nice

  • @clairgarrick9842
    @clairgarrick98422 жыл бұрын

    I always forget how to derive the quadratic formula from completing the square.

  • @theophonchana5025
    @theophonchana50252 жыл бұрын

    #QuadraticEquation

  • @RieneReaper
    @RieneReaper Жыл бұрын

    I’m 22. I missed my math test by 5 points. Hands down the best mathematical/science tutor.

  • @solomonigba2580
    @solomonigba25802 жыл бұрын

    I have some questions here

  • @theophonchana5025
    @theophonchana50252 жыл бұрын

    a = 3 b = 1 c = -1

  • @theophonchana5025
    @theophonchana50252 жыл бұрын

    sqrt (-36) = error

  • @khalilfuller4939

    @khalilfuller4939

    Жыл бұрын

    i root

  • @theophonchana5025
    @theophonchana50252 жыл бұрын

    y^(2) - 4y + 13 = 0 y = (- (-4) + sqrt (-36) ÷ 2 y = (4 + sqrt (-36)) ÷ 2 y = error

  • @khalilfuller4939

    @khalilfuller4939

    Жыл бұрын

    So it will be +/- 6i

  • @khalilfuller4939

    @khalilfuller4939

    Жыл бұрын

    So it will be +/- 6i

  • @kainacorsiga3590
    @kainacorsiga35902 жыл бұрын

    Oh

  • @Tarzanaxx

    @Tarzanaxx

    2 жыл бұрын

    Square root of. 20 IS NOT 5. ERROR IN EXAMPLE.

  • @Tarzanaxx

    @Tarzanaxx

    2 жыл бұрын

    Square toot of 20 is 4.47…

  • @zbigniewbrzezinski8869
    @zbigniewbrzezinski88693 жыл бұрын

    You forgot -1 on the equation ! (First example)

  • @nickmasters6239
    @nickmasters62392 жыл бұрын

    stop looking at the comments and look a the video

  • @theophonchana5025
    @theophonchana50252 жыл бұрын

    a = 1 b = 6 c = 4

  • @theophonchana5025
    @theophonchana50252 жыл бұрын

    sqrt (-36) = invalid input

  • @MathAndScience

    @MathAndScience

    2 жыл бұрын

    You need to get a calculator that can give you a result that is an imaginary number. When you take the square root of a negative number a regular calculator cannot compute the answer but a scientific calculator will give you an imaginary answer which is the correct answer.

  • @jessethompson8606
    @jessethompson86062 жыл бұрын

    @19:28 oh it is definitely still considered some form of black magic..

  • @nripeshkumarmishravinayak664
    @nripeshkumarmishravinayak6642 жыл бұрын

    SRIDHARACHARYA RULE

  • @kcjones2048
    @kcjones20482 жыл бұрын

    this was not a good this shit made me more confused

  • @eriktredario

    @eriktredario

    Жыл бұрын

    i feel you hulk

  • @user-yc6rd5pq9e
    @user-yc6rd5pq9e Жыл бұрын

    Wow learning it today hours before my exam thanks a lot 🤗really helped

  • @ikennauche9624
    @ikennauche962421 күн бұрын

    Thank you so much

  • @vivicheung4843
    @vivicheung48432 жыл бұрын

    Thank you so much