Solving a Quadratic Equation by the Quadratic Formula

[SuperDiosan]

the cont is ok.but impossible to see it.

[minkusbc]

@SuperDiosan I agree that it should be upgraded, from 5 years ago. However, to say that it is "impossible" to see is an over the top. I read out each number as I write it. However, I will redo this as a clearer video.

[rebeccaruiz70]

This video went viral on New Hampshire

[minkusbc]

@rebeccaruiz70 Hi, Rebecca, can you expand on your comment? - minkusbc

[MadzzZ529]

what is the number under the square root is negative?

[minkusbc]

@MadzzZ529 If the number under the square root is negative, then you can NOT solve it with a Real number (a rational or irrational number). The answer can be solved by using imaginary numbers and the complex number system.

[goofygonads17]

omg thank you i had a swim meet so i ned this thank you

[thriller645]

Thanks.

[msacaringal]

OH GOODNESS! SOUND! thank you!

[derrickbanes]

you're a very good teacher. thank you.

[LXbomber]

My goodness gracious I didn't understand this until now thanks. Also what mark is that pen/marker its cool.

[1b2w3w]

Thank you for your video.

I hope you will make another vidoes.

[Birkinbag09]

Thank you so much I was so stuck on this 

[bboyrulz]

==' so sad... i have to do this in year 9. but thanks m8 you've helped me so much :)

[slovan]

You sir, are a lifesaver.

Thank you.

[beckbeckah]

Really Helped me. Thanks so much!

[00Allsmiles]

Can you please re due the video with a better camera? Thanks

[vlissa2000]

dude, ima buy u a new camera lol

[vThECaBbAgEv]

@NoXAdmiral I cant see feces either...

[irishwowplayer1]

thanks man i got a test in the morning and this is going to really help me as i use this a studying

[mashmarriner]

Mate u helped me so much thank u. And might sound gay but ya got a propa carmin voice Haha

[NoXAdmiral]

cant see shit dude.

[minkusbc]

@NoXAdmiral I agree, it is not great, but if you can't see anything when over 46,000 have seen something, then, ........

[ronniebeverage]

fantastic video, cheers! quick question, what happens when the numbers that would be in the place of a b or c in the original equation are just x?

[minkusbc]

@ronniebeverage If there is no number in front of a variable, it is always a "1". So 3x^2 + x - 5 = 0 is the same as 3x^2 + 1x - 5 = 0 and a = 3, b = 1 and c = - 5 in the quadratic formula. If a term is missing, then the number is "0", so 3x^2 - 5 = 0 has a = 3, b = 0 and c = - 5. And 3x^2 +1x = 0 has a = 3, b = 1 and c = 0 in the quadratic formula.

[23SharonJessica]

You're awesome!! I've got test tomorrow..and Im saved because of this video..yaaay! :D

Im very grateful to you for this.

[JuStAnAsIaNboY]

You sir, just blew my mind

[NViES]

Dude, u just saved my life! THANK YOU!!! I'm subscribing!

[MsBrendan11]

thanks(: now i can do my homework.

[videoplayer511]

Thanks so much my exam is tomorrow and you've helped me. Thankyou

[rebelcac99]

thankz.its a big help

[ExMarKaSpoT]

easy

[fantabbidosis]

bit lost.. why did it become 15.44..? stupid question?

[wolfgirl723]

OMGOSH THANK YOU!!! :)

[whatthefrenchtoast97]

your so much better than my math teacher

[cuponkbros24]

Soooo helpful thanks!!

[subby7866]

OMG this one is so confusing

[Darionthisguy]

thank you very much

[Entertainmentwf]

Nice video but, you tend to use far too many universal terms. There exist many quadratics in higher domains of number sets which cannot use this special case.

[vickyyyVVV]

WTF

[neilyton]

<3 ty for making this slow enough to comprehend!

[gangstaz001]

dude i tried this but it always says maths error on my calc??? dnt get it...

[chocalatecocoloco2]

FUCK algebra... i'l never learn it...

[mbctv6]

thnks alot....u help alot more than my math teacher

[gfunkel200]

What happens if the +5w was a -5w. Would that change x = -b+- to x = b +-. The author of this video notes that the first b in the formula is opposite to b in the equation.

[DianasaurausRex]

thankyouuu!

[steven101x1]

thank you

[toppimpkid11]

i need help

[jack390]

thank you soo much! i was stuck at finding the answers.

@jenn9414Princess, im also in grade 10 and i understand it! :D

[yeaitwasme]

i literally sat with this as my homework gor 2 hours straight and i didnt get it! this video got me to the solutuon! thank you sooooo much! it really does meen alot to me! please continue to make videos!

[1080portal]

how do you square root to decimal?

[algroshaw]

by using a calculator.

[mikemike8000]

Brilliant work keep it up!

[JLyonsVids]

Thank you so much! keep it up :P

[dolcegabnna]

you just saved my life!!! i actually get it now because of you!! thank you so much...you made it so much easier !!

thanks again!

[jenn9414Princess]

LOL i love how everyone is like, im in college and i didnt understand it... im in grade 10 math and wass soo lost!

Mister.. i owe you BIGTIME thank you!

[algroshaw]

Same here, but i have my exam friday, and he probably saved me from failing.

[PS2N8J]

dude! you explained this so well, thanks!

[paperboyrocks87]

thanks for your kind help, My teacher wont even explain it to me like that. My also does not provide clear examples... I am using College Algebra with application for business and the life sciences by Larson/Hodgkins...ISBN-13: 978-0-547-05269-4....

[xFIRExxxGIRLx]

who is joe? :S

[OoNBrownies]

thank u so much i forgot how to do this and im in cal 2 u may have saved me ;)

[liliya888]

whats cal 2? calculas 2? wow our school only teaches up to calculas 1 and its not required... we just have to do algebra 1 algebra 2 and geomatry

[04callwilk1]

thankyou so much your great:)

[Iplaywowandhalo]

Thanks a lot keep up the good work :)

[Iplaywowandhalo]

If you had a problem like 2h^2-5h=12 you would subtract the 12 to get 2h^2-5h-12=0 correct?

[minkusbc]

Yes, that's correct. Then in the formula, a = 2, b = - 5 and then c = - 12. A common error is to leave the 12 on the right hand side and then using c = 12 in the formula

[Iplaywowandhalo]

Omg dude thanks why can't my math teacher be like you!!

[bth1983bth]

but the square root is not 10.44 its only close so leave it at root 109

[minkusbc]

You're correct, if you want an exact answer. However, if you want an answer you can actually use, such as how long to cut a board, then you will want the decimal answers to whatever level of accuracy you need.

[bth1983bth]

DECIMALS?????

[minkusbc]

Yes, you can actually have any numbers involved here, decimals, fractions, imaginary, complex, roots, irrationals, etc. Just plug the number into the formula (no matter what it is, even a variable) and crank the handle and out pops the answer. Plug, crank, pop...

[Relyt461612]

Thanks!! This helped me out a lot =).. I understand it now =).

[naturvetaren92]

Thanks, this clarified things a bit... My math teacher always is ahead of the students in my class, so sometimes it's difficult to get what he means.. Thanks for uploading!

IMO it's more fun to use the completing the square method, though ;)

[SechkiJjang]

wuoh!!!! ur amazing dude thanks for teaching me this new trick u rule!

[andreisextreme]

I... might pass my test now!

thank you for your video. it was very helpful and made it easy to understand.

[acecf23]

You are a genius!!!!

[Sarah78679]

Great video! Thanks Thanks Thanks!!!

[certifiedjagga]

Wow, this makes it so much easier when you explain it than my teacher.

[robpilot2]

Good vid, cleary explains how to solve a quadratic equation using the quadratic formula. It is always nice to see where the numbers are taken from and where they are placed and used in equations.

Thanks for the good vid, hope you produce more in the future. will check out the site aswell.

[KittyKatty2020]

awsome, it seems that i can never get math. this a great help to me!!! keep doing more!!!

Thanks for putting this up! :)

[DeMichaelSuperFan]

I might pass my test tomorrow! Gotta study more!!!

My teacher was like "hmm you should know this already... -.-"

You're saving my life right now, just to let you know :)

[Sweet47Jane]

I never used this, since I could factor, although when wanting to find the values of x even when the quadratic polynomial was not factorable, I would use this.

[Jaimmelove]

you are amazing! You made something that looked like a completely different language to me seem so easy to understand. I'll have to watch the video again while I'm doin my homework. lol BUT I feel like I actually can understand it and do this. Thank you so much!

[Reester18]

Thank you so much, it's very clear to me now, (the whole order of operations thing always screws me up.) This was a lot of help =)

[Teleranger4]

Really nice. Keep up the good work !

[cobenblack]

Thanks very much. I've just learnt the quadratic stuff of you now :)

[guitarsmakemesmile]

Thanks! really appreciate the channel.

[j3tski33]

thank you very much!! this is so helpful to all who are in need!!!

[jessande2007]

Thanks a lot!!! Very helpful!!!

[Gjkeane]

This has helped me thanks

[anniekaboodle]

thanks... i learned this last year but totally forgot it.

[mollie88]

Thanks for this!

[dahww2013]

wow i learned this when i was 10

(yes ten) and when i learned it seemed easier

[cjmitz]

ass

[onavi840]

thank u sooooooooooooooo much

[Janjubie]

Thats what was stumping me i thought the equations had to be perfect!thx

[natsu76]

thx !!! now i remember how to do it...i'm reviewing for an entrance exam and it really helped me... two thumbs up !!! :D

[CriaderoAtlantida]

thanks a lot

[mayeyoung]

thanks help out a lot

[Logictech111]

L33tmaster and boublih, I'm assuimg you are americans and flip burgers for a living? Sure, that involves alot of thinking!

Thanks for posting this :) Next video, you should include how the quadratic formula was derived from the standard form formula ax^2+bx+c=0 step by step.

[Spacemal]

Thanks for making these understandable.....a lot more interesting than I was taught..cheers

[TEDtomo]

this guy dums it down to much, he makes it longer, more tedius and more confusing.

good teacher though.

[minkusbc]

Sorry to take it slowly, but remember a lot of people watching this video did not understand it in a class - maybe because the teacher went too fast!

[h1dro]

agreed.

[ThemLizards]

Wow, awesome! Thank you so much man! My teacher is Chineese, so it is sometimes hard to understand her, which makes it difficult to learn. Since im in a college math class MA-82 (Non-Credit) It is verry important that i pass it. Im studying for my finals, and your video helped me alot. Im gonna' go check out some of your other ones! thans again! God Bless you!

[kitsonrox]

Thanks this helped me a lot. After watching this I actually passed my math test.

[L33tm4st3r]

ur a nerd, get out of ur mom's basement

[shotatluv777]

o now i get it. my teacher mr.halseth makes dis math thingy hella confusin.

[arykhoon]

bro....ur better than a teacher...youre a miricle man

[makkaulahsial]

i just understood something i never did in sec sch. thx a million!

[sanshuz]

joe Quadratic. lol..................

[nojomen2]

Dude, maybe because of you, ill pass my test...I hope thqt I GET OVER IT..

[DopeBoyReyes]

Thank you SOOOOO much! This has made my life so much simpler! You're too cool man, helping people out for free. junaidn18 you're a fucking douche bag, go to hell you stupid fuck.

[sebkl21]

junaidn18 I would beat you down so bad. This man is helping thousands of people for free you should thank him or maybe just quit school if you haven't already and go work at mc donalds cause your just too stupid.

[junaidn18]

hey dipshit i dare u to beat me down. that mans a fat wanker. i no way more than him. i was the only one to get a 25% ogg sixth form scholarship at one of the best sixth forms in the uk so up urs. go do one u fat wanker

[nrmiller23]

yeah, and you're gonna get kicked out in a second for that kind of attitude buddy.

[junaidn18]

my balls itch

[cjmitz]

lol

[sebkl21]

junaidn18 I would beat you down so bad. This man is helping thousands of people for free you should thank him or maybe just quit school if you haven't already and go work at mc donalds cause your just too stupid.

[kraniun]

absoultley amazing thank you alot for helping me

[paragdhungana]

i would say you r really one of the best teachers...

[lolimaejkpfjwp]

the -4 is part of the quadratic formula

[Oblivianisathand]

Thanks for the example of how to do this!

[kegs616]

wow.

lol are u a teacher? if not. u should really take mine's job... cuz shes a dumbass cunt who doesnt teach at all.

[clockingmath]

Thanks!!! finally it's all clear to me!!!

[shadowraven94]

i LOVE quadratic formula

[colorfulworld15]

YAY!! Thanks a lot I was having trouble with solving at the end...but now I get it and I am really HAPPY!! THANKS!

[theclevelandindians]

nice vid. I learned alot thanks!

[yellowducksarecool]

Yay for maths!!!!

[FakeFashionxx]

Thank you, sir. You just helped me tons on my math project.

[Darkleashed]

thanks, you helping me pass my maths exam :)

[jairus678]

tnx dude i suck @ quadratic...tnx for making this vid...and tnx for giving me some tips...

[RitchieBrinckmore]

w00t

[verikool3]

thanks alot man that helped me so much on my math homework keep posting!!!

[penguinlova19]

what

[ahhao1993]

thxxxxxxxxxxxx ^^

[dontcareanymor]

Very nice work.

The point that I never understood before this was the -4 (a)(c) but now i know that you dont ACTUALLY multiply NEGATIVE 4 times A and than C.

You actually take 4, Multiply times (A) Than that Answer times (C).

Than you subtract B squared by the answer you got for 4(a)(c).

And thats what you get for what you want to square root.

Thanks alot.

Tell me if all that ^ was correct.

[minkusbc]

You got it!

[tearsangelz]

but why is there a 4, the 4 came out of no where?<- i don't get the -4 part.T.T

[minkusbc]

Don't worry where it comes from. It's just like D=2R, some formulas have numbers, like pi, in them.

[ChaosRhythmic]

wow,more simpe more easier,thanks u dude =)

[007paintballmadman]

thank you! this explains it so much better then my text book.

[douglashaynes]

hey thanks for taking your time to put this up.helped me alot =)

[gamemaster014]

omg thank you so much the first time i looked at this when my teacher did it it looked so confusing i couldn't get it then you make it look really easy thanks

[BustYaFlappsApps]

Thanks for the help mate my teacher cant teach for sh*t haha :D keep up the good work XD

[4EVAORLANDO]

wot if ur not allowed a god damn calculator

[minkusbc]

You would leave your answer as a radical, such as 3 plus or minus root 15. The art of working out square roots by hand is pretty well lost. I had to learn it in grade 9 (1960), but it is now out of the curriculums,

[eminemjohncena]

how old are you?

[minkusbc]

I'll be 60 in December/2007

[eminemjohncena]

wow thanks ur doing a good deed helping kids in this stuff. i'm 15

[green06sb]

Thanks a lot for this...it really helped me a lot!!! :D:D

[stuartmackinven]

In the part where you say -84, then you make it a plus......why do you make it a plus? I'm confused. I want to know, im not bitching or anything :-)

[dominicodom]

Because a negative number minus a negative number equals a positive.

[pedrovieiranerd]

Oops sorry; got it wrong there. Here's the one:

x²-2x-2=0

[minkusbc]

If you put a= 1, b= -2 and c = -2 into the quadratic formula you get x = (2+root12)/2 or x= (2 - root 12)/2. Since root12 = 2root3, this can be simplified to 1 + root3.

[pedrovieiranerd]

Sorry to disturb you again but could you also help me on this one by using "Completing the square" please ?

x²-2x+1-2=0

[airpizza]

hey, im moving to canada sometime soon, and i dont know exactly what grade this is used in..is it 9th grade or 8th?

[minkusbc]

In western canada this topic is done in grade 11.

[airpizza]

thanks

[eminemjohncena]

10 i think where are u moving from?

[minkusbc]

I'm not sure what you are referring to.

[pedrovieiranerd]

Thanks alot, was stuck there and worried I wouldn't be able to hand it in.

[pedrovieiranerd]

how do i solve this equation by factorization? :

2x²=72

I know, first thing to do is put 72 to the other side and it becomes 2x²-72=0. But then i don't know what to do. Can somebudy help me please; not just by giving the answer but by explaining proccess ...

[minkusbc]

Take out the common factor (2) on the left hand side. This leaves you with 2( x^2 - 36) = 0. Now, factor the bracket that's left. This now leaves you with 2(x+6)(x-6) = 0. SInce 2 canot be zero, then each bracket could be zero. That gives us two small equations, either x + 6 = 0 OR x - 6 = 0. Solving these gives you either x = -6 or x = 6.

[pedrovieiranerd]

Thanks mate. I was kindda stuck there. It's part of my math homework by the way, and I was worried I wouldn't be able to hand it in.

You see the book gives the aswers at the back but doesn't show you how to get there and all the examples don't envolve a number before the x² ...

[bikinggod4]

you have well and truly saved me lol i have another quadratic which is set out differently so i dont know if the same applies for that, 2Xsquared+6X=2X+1 reply to me please

[101BananaSplit]

Thanks, very helpful.

[lode43]

Thank you very much.

[MathWhiz05]

Nice vid!

[QuantPika]

Actually that is quite interesting : that's the only way i learnt it (i'm french) when i was 14. I just wonder how old are u all, & where u r from! All couintries have such differents way of teaching maths!

[minkusbc]

I'm 59 years old, and I live and teach in Canada, Acyually I just retired from teaching 33 days ago, so now I am on the free market, exploring Math and looking to make money!

[Wafflepudding]

Thanks man this was helpful.