Discriminant of quadratic equations | Polynomial and rational functions | Algebra II | Khan Academy

[@CrazyNateKosty98]

I gotta give it to you, I learned more from you than my teacher

[@NeekoKid]

Nate Kosty lol my teacher tells us to watch this guy

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if she knew him, theyd prolly marry each other

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Nate Kosty sameeee

[@lancestephenson2977]

Nate Kosty i know right

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Edgel Alarcon go

[@skuffd-semicolon]

The amount of OOOOHHHH!!!! moments I had after watching this.......

[@sayloraks9334]

Wow. Thanks for making me feel bad. I had none😪

[@FishNugget-we9oi]

@@sayloraks9334other people learn differently it good to let those who dont know to learn

[@crazyloco97]

I learned in 2 minutes of this video what took me 1 hour in class to get confused over

[@anaisperez2704]

same

[@todayjanuary2012]

My teacher: ***stacks piles of papers on my desk*** DO IT! You: OK... Let's go over this slowly YOUR THE BEST!! I ACTUALLY UNDERSTAND WHAT I'M DOING IN MATH CLASS NOW!!! :D

[@nojam4988]

2021

[@Ineedaname-ym2bo]

2024

[@musiciseverything333]

Thank you dude! I fell asleep in class. Watching your videos are going to help me get through Algebra 1.

[@aucool7869]

khan academy just makes my life easier. My teacher makes everything all complicated but Sal just makes it simple and easy to understand. THANK YOU KHAN ACADEMY

[@futurine8197]

Every time I finish a video is like "this is so easy how did i not understand it before"

[@tazreenkhan4890]

Deciding to watch this video is one of the best decisions I ever took in my life.

[@ashaa.5616]

oh my god, thank you so much for this because math has not been life.

[@colemanroberts6827]

+Asha A. crystal castles!

[@randomfandom33]

mmmmmm... saying "oh my god" is technically blasphemy

[@glnpy]

@@randomfandom33 be quiet

[@codingwithkenny6492]

Sal is the best math teacher in my opinion. He simplifies the mathematical computation and makes it much less confusing than most Math teachers.

[@loversjustkeeploven]

Aced my final. thanks breh! u saved me from military school.

[@balqisaadan8132]

how old u now

[@samsungsaiyam1090]

RIZZ

[@balqisaadan8132]

@@samsungsaiyam1090 hshaahhaah u wrote that comment 12 years ago, I was js wondering

[@liquidsmoothgrr]

Watching this because my teacher got mad and she didn't teach this lesson to us but we're having a quiz about this tomorrow. Thanks a lot.

[@Flameplaysofficial]

I learned more from you than my Teachers way less confusing

[@just_magneee3185]

Teacher in this academy is better than my teacher.

[@iamthejustin7420]

omg what would happen if khan academy dies, then i would fail every maths test LOVE YOU KHAN ACADEMY KEEP IT UP

[@rajatkamalpolisety2864]

khan academy will never die (sal will tho :( ) lol

[@shannonfernandes1]

Rajatkamal Polisety I will make sal live 4ever

[@benwalker3771]

i dont think i would pass tests without you. cheers mate

[@valeriecrespo4637]

What if you have to solve for no real solutions with [i]

[@mikeadriano4391]

you can still solve them using the formula. if b^2-4ac is negative [(-b^2+4ac)^(1/2)].i equals to (b^2-4ac)^(1/2)

[@thepostmandelivers.5124]

Great video straight to the point and clear, great job

[@stasha8611]

That really helped

[@noblessus]

I really like your videos Sal, they are very useful for me. Quick comment: Instead of saying discriminant=zero means one solution, I know it would have saved me many hours of research if someone told me that we still have two solutions (like always with quadratics) but in this case the solution repeats two times. Eg: x^2-4*x+4, even though it's discriminant is zero, it still has two solutions, which are x=2 and x=2. Again great videos and I hope you do more calculus and physics videos!

[@aletheaplass6557]

Your handwriting is superb

[@diguiane]

Now im done with my modules

[@TheWhatnow9999]

You save my math life thank you so much

[@bryannguyen658]

Agree

[@GEGE77R6]

+Bryan Nguyen +Ryan Houston he may have saved your math lives but your grammar lives needs work.

[@AliceDiableaux]

+GEGE77R6 How can you possibly deduct anything about someone's mastery of English grammar when he only commented one word?? Jackass

[@Ice_Screamer]

helpful af

[@uttkarshjha8265]

My god 11 years ago Cant belive

[@dimeg52]

I’m taking algebra 2 this year and the original algebra 2 teacher went to another school and now I’m stuck with a teacher who’s said he has never taught this before. So, this really saving my career.

[@metallizard88]

I actually started jumping of joy because I finally understood it

[@monicaairamonserate7471]

omyghad, thankyouuu!!! ❤️

[@YamenNazer]

This is very good i loved it..but i have a question..how did we explore the formula of discriminant ?

[@ForEvaW15h1nG]

Well... the consistancy in your video's is through the roof. i've just started A levels after getting a good grade in Math in Gcse ... there is quite some confusion among the topics i'm studying in this new curriculum... some of the topics i've had trouble in I've searched for help, YOU have covered them all. Thank you.

[@Aashii777]

Thank you! ❤️

[@twominutepenalty]

@Rowan9789 if 5x^2-6x=0 the constant is zero. you could feasibly write the same equation as 5x^2-6x+0=0. either way, the y-intercept would be 0, as would the x-intercept.

[@drewneugilos8681]

Is B always negative?

[@xXxKimballxXx]

ItsYour Gamer yes, it’s part of the equation.

[@SirNanothy]

if the value for B is already negative, then when you plug it into the quadratic formula it would then be positive.

[@clairenime]

5:42 wouldn’t you move the a to the other end with everything else? My teacher says x^2 has to be positive

[@shhzaid]

Thank u khan acedmy

[@xiaoxiao5088]

Can we use the discriminant formula when the equation in linear?

[@Dusevic]

wooooohooo imaginary numbers!!!! u should add imaginary numbers to your linear algebra playlist. 'cause it would help me with my college course! especially rref'ing a system composed of imaginary numbers

[@rascaldevilz]

how does two solution look like in graph ??

[@nathanaellandicho]

it's gonna form a parabola. the two solutions are the two points where the parabola will hit the x-axis.

[@obendesmond]

Hello sir, please which software are you using to teach? its pretty cool

[@pitrochied]

watching after 11 years also.....

[@girlicious102]

thankss this video helped alot

[@shannonfernandes1]

gucci jessi hey

[@crazer96]

It touches the x-axis in two places, so the parabola goes down touches one point on the x-axis and then when it comes up again it touches a different point on the x axis.

[@shizu019]

You save me from my sufferring thank you

[@sen-te8oq]

i can safely say this explained and taught me more than my school.

[@rushikeshsurywanshi2286]

Iam watching it now and thanks

[@paulceltics]

@loversjustkeeploven really? thats pretty awesome

[@Karin6509]

So I put the "i" at the end of the solution in Aleks when the answer is negative?

[@awol9914]

Very helpful. Thanks!

[@marlyjoysereno1264]

wait,wait so where do you get on 5:24 (the orange color) there is discriminant so where did you get the 9-4? ( Discriminant 9-4(1)(6) )

[@sun0tea]

b is 3 so b squared is 9. You subtract 4ac from b. 4*a (which is1)*c(which is 6) So, b-4ac is 9-4*1*6

[@omardotbio]

a must be equal to -1 not 1

[@GndmMkv]

man it helped so much that i feel like not going to school anymore

[@foxenbox]

I miss 2010

[@YBNKASHWAYS]

Same

[@elbay2]

Well done! What S/W and H/W set-up do you use as a "black board"? It's very easy on the eyes!

[@yellowblob3573]

THANK YOU SOOOOO MUCH (:

[@sebru]

is there a nature of roots video? i cant find one and this is the lesson in my school

[@iiiijoseuy]

what real life application does using the discriminant have?

[@HPatel-vf7ih]

You can use it for engineering (and stuff like that). Also, if you want to go to law school or med school you have to know it.

[@HPatel-vf7ih]

SpiritWolf2K Hahahahha, yeah.

[@kamilo1175]

oJose developing your brain

[@shreyanshpandey4022]

Employment 😂😂😂😂

[@丹ら山工几]

Thanks

[@jacobrodriguez9980]

How will I know if it is rational or irrational ?? And how will I know if it is complex ??

[@ahmedsarker3555]

sir khan one question, for the first discriminant which is bsquare - 4ac > 0 you said there will be two solutions positive and negatice but in this case, the negative is less than zero so how come there can be two solutions. In this case can we say both the values which are executed are positive instead of one postive and one negative since it would consider that one of them is greater than zero but not the other one

[@noobkosh]

why I cant find this video in the website??

[@anaisperez2704]

i wish i had you as my teacher instead sal

[@ManhwaSensei]

i came from art videos to this

[@universalponcho]

This is dope

[@xcelpast]

thanks bro

[@shobharanipl6129]

amazing

[@jamieg6173]

SO HELPFUL! Thank you!

[@loversjustkeeploven]

@paulceltics yea seriously. i live alone but my parents still support me. and they would have made me enlist of i didnt end the my junior year with C's.

[@ImFlamez]

With the internet, who needs school?

[@ayyoitzToko]

aiight bro. cya

[@kannanr837]

@khan how come we get 2 parabola for a quadratic equation... won't the graph be a single parabola that meets x-axis twice...

[@moonmoonmoon11]

how did u get 4?!!!!

[@haideralikhan5976]

love ya mate, noice

[@akeelahmad821]

If there is cubic equation?

[@theophonchana5025]

x^(2) + 3x - 6 = 0 x = (-3 + sqrt (-15)) ÷ 2 x = error

[@theophonchana5025]

b^(2) - 4ac = -15

[@dylangarcia7314]

if the discriminant b^2-4ac=0, the graph of f(x)=ax^2+bx+c, a not equal to 0, will touch the x-axis at its vertex? True or false?

[@hongrand]

Thank you!

[@randhawaheed2720]

THANK YOU THIS IS SO GOOD but I've a question how does it matter if it is a rational solution or an irrational solution

[@KayMarie-es3cr]

Nobody Iknow Yes.

[@randhawaheed2720]

@@KayMarie-es3cr what does yes mean

[@KayMarie-es3cr]

Nobody Iknow Sorry. I thought you asked if it matters if it’s rational or not

[@randhawaheed2720]

@@KayMarie-es3cr it is completely fine but do you know how it matters if so

[@KayMarie-es3cr]

Nobody Iknow do you mean why it matters?

[@wardairfan9074]

Can anyone give me an example of discriminant

[@빨갱유모차길냥맘]

판별식이 0이라는것은 곧 2차방정식이 완전제곱식의 형태라는 것과 같네요 잘 배우고 갑니다

[@gkgames7589]

what if its not equal to 0 and hahs 4 numbers in the equation

[@labeebahmad6287]

Khan academy should be the most subscribed channel on KZbin change my mind

[@peterpro9250]

What if the real solution isn't rational??? Pls tell

[@jyavant]

What about for all real numbers?

[@moonmoonmoon11]

oh never mind!!!!!! :)

[@Chaosflyex98]

You are way better than my math teacher, and I wish you were my science teacher because he is just so... argh. =__=

[@looking_33]

Why am I learning this in algebra 1 if this is algebra 2

[@handler514]

lookinglasstie did u find your answer after 3 years?

[@Chaosflyex98]

I don't have a point. My comment had nothing to with you. Now good day, sir.

[@user-uwo]

thank you for the arabic translation

[@Chaosflyex98]

Thumbs up if you have an A in Algebra I! :D

[@monicaairamonserate7471]

yeeyyy

[@fearz-4367]

1 person in 7 years.

[@AnupPriyadarshi-zu1hu]

So this is 14 year old

[@abdias99]

I learned more in 10 mins than in 2 hours from my class thx 🙏🏽

[@zeyy8090]

So no one watches this in 2021?

[@Luna-pr7lb]

oh god my teacher is so useless istg

[@Chaosflyex98]

I'm quite surprised that you replied to me after 11 months. Smh..

[@zoneupgo]

im too dumb to understand

[@anqichu-br6cd]

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[@0illuminate]

0 illuminate

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it's what BRO? huh whats wrong with saying BRO

[@shannonfernandes1]

J UnknWn lets see after 4 years

[@abigailmiller7193]

How about 5 years

[@millianford7389]

How about 6 years

[@benhawk4214]

@@millianford7389 6 years and one month

[@skuffd-semicolon]

@@benhawk4214 6 years and 5 months anyone? Also, a little time capsule for you 202x peeps: the year is 2019. Memes still exist and currently we are facing the death of "say sike right now" and the meme community is well saturated with Pewdiepie slang such as "bing bong". Speaking of Pewdiepie, last week he hit 100 mil subscribers, got married to Marzia, and killed the ender dragon in his very popular Minecraft series.

[@fabiogaming9268]

JOE LIKES GUYS

[@HACKER-BHAVESH]

Omg 10 year ago