How to use the quadratic formula | Polynomial and rational functions | Algebra II | Khan Academy
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- Опубліковано 27 вер 2024
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Introduction to using the quadratic formula.
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I learn more from you than my math teacher
***** IKR
I thought I was the only one... hahahaha
JustmeAthena123 xd, my teacher was pretty good, she was more helpful than this, this is just for reference since i forgot/ i have to finish my honors summer packet
you have a shit math teacher then
Carol Nguyen lol my math teacher showed me the video
In class we spend weeks on a subject. I just learned what I needed to in 15 minutes for my test tomorrow
TallishOak are these 3 different equations? I dont understand this
yo same
@Deadlock T so whats the score?
This is one of the many, MANY, reasons why public school is trash.
Students: Can we learn how to do taxes?
The Education System: Screams in quadratic formula
Me: spends an hour max on Google
"Hey, that was easy!"
This is actually fairly useful in lots of fields, like engineering and even programming. We do have computers do some of it for us, but it's still useful to learn this. That said, the education system is for you to prove that you are able to learn advanced concepts, not for you to actually remember all of it.
Levon Aronian Yes, it can be useful I understand that, but statistically speaking most people learning this won't use it, wasting a lot of time that we could have used to learn better things
Abel Alvarado well u always have ur free time to learn other things
@@saturn6305 Yeah but you better believe I'm not gonna waste my time with something I don't have the desire nor need to learn
I want to be a math teacher, but I needed this refresher. I always mess up the formula because I didn’t learn it by heart. I imagine 99% of people struggling in math just are missing some basic building block like this, and I’m part of that 99%. Thank you again for making math less mysterious and clearly wonderful. I’m arguably more proud of my energy points score than any other academic accomplishment in my life lol.
Sir I believe that you may have saved my grades, you indirectly told me what I was doing wrong.
blick beared same here bud
I've watched about a million of your videos because I came into Algebra in the middle of the semester and now I have the EOCs and I was freaking out that I didn't know any of it. THANK YOU THANK YOU THANK YOU.. I have been saved and now I don't have to worry about failing 8th grade!!!
Onika Bogdan Ik I’m kinda late but is the eoc hard???
Lmao, failing grade 8. You can't fail grade 8. Late ik
Onika Bogdan so your only a year above me how’s sophomore year?
yo you're now a sophomore
@@olympias1528 you literally can.. I know 4 people who got held back in 8th grade
For the second example, I spent like 15 minutes trying to figure out why my calculator was saying math error until I watched the rest of the video and it doesn't have a real solution....
Raif Mas 😂
This teaches you more than a zoom meeting ever will
At 8th grade (where I am right now),I have been studying hard in school and at Math. I challenged myself to get at least 85%/100% of the answers when having a test without watching some tutorials and it strucked me that I can do it without any help of others
I want you to believe in yourself,you can be great by studying hard and please do not let your guard down
Hows college mate
@@fearr3951 pretty sure he has a job by now
How’s life
Bros in grade 8 learning quadratics 💀
Of all the math I've learned I've used none of it in the real world. :(
I'm sure you've added at some point in your life 😂
@@Kometheus not algebra
@@user-nt7ew9di7v He said all math 😂
bashpr0mpt You don’t use a majority of what you “learn” in school. Simply memorize it and regurgitate it on paper.
90% of algebra will use in the future are Algebra Teachers
5:17 you can hear gears grinding together in his brain . . .
Why would I need Algebra or these in my life? I really don't want to have to do anything with maths.
true
I think I hurt my brain. That's quite a formula
Heidi Borjgman Schmange not really I'm in 7 the grade and we're learning it
wtf i am in year 10
Trash CAnd Kids are learning harder stuff earlier and earlier. In a few years, we'll have first graders learning calculus.
Hamza Umair yeah i have honors math though, because normal ed. kids are taught this in like 9/10th grade
MLG R8DR805 i am studying thing that my brother in collage is studying
OK this is mad. I was searching how to do this for my homework and the example he used was the same as my homework question!!
You are the best. I learn better from you than my teacher in school.. Your techniques are great!
I'm Rick Harrison, and this is my pawn shop. I work here with my old man and my son, Big Hoss. Everything in here has a story and a price. One thing I've learned after 23 years, you never know what is going to come through that door
inn0version _ what
I've seen this else where, do your home work and clean your room
Lmfao all those NPCS above my comment
Today i brought in a 1985 handgun that mozart used to kill lincoln
Cheers bro I’ll, drink to that
i swear he uses magic to teach people through a video
I'm in a duke program for advanced 7th graders and we are doing an SAT. Before this I didn't understand this. Now I have NATIONAL HONORS for my score of 740
740 is pretty average...
Who else is staying up at 1 AM watching this and trying to get your homework done in a panic??? 😂
Use photomath. It does it for you and shoes the work. It doesn't work with geometry though, but algebra works.
I don't know, they're reallying pushing you to get the premium
omg its 1:02am and that's exactly what im doing
Lol that’s exactly what I’m doing
i feel attacked
Quadratic formula was so confusing for me before! My teacher has to do the most complicated ones first, and you get it in one video! Thanks!
Do you use a computer mouse in doing this? Wow, that control is amazing 😵
nathanaellandicho he uses a drawing pad most likely
Probably uses a Cintiq or similar.
He always says 'sorry about my handwriting' so he uses certain kind of a drawing pad
www.onlineuniversities.com/blog/2012/04/de-mystifying-khan-academy-screen-capture-for-educators/
he uses a wacom tablet
Haani Nehvi i use a digital drawing pad and the curser never leaves even when you move away the pen
Monetize all your videos. You deserve the revenue.
Khan Academy is a non-profit organization, however they have multiple donations over 10million dollars EACH, and dozens of donations in the range of 5 to
Throughout the years this channel has saved my butt so many times. I hope whoever makes these videos is living a prosperous and happy life 😌
Its Sal Khan, he's the founder and CEO of Khan Academy. So yeah, he's living a pretty good life.
@@demxnia6736 CEO of a non profit
@@Goosiepoo Sal Khan's net worth is 220 million, so I would say he's living a pretty prosperous life
at first I thought you said 'preposterous' and got kinda worried for a sec...
He's graduated from MIT AND from Harvard Business School. His net worth right now is 260 million, so yeah; he's prosperous.
if "b" is a negative, does the "-b" part of the formula change the "-b" into a positive?
Luke Qiao yes
Luke Qiao yeah
Very late. -b when b=-x =--x=-1•-x=x
if b is a postive then it will go like - (b) = 1 x (b) and if b is negative then it will go like - (-b) = -1 x -b which is a postive. 7 years late but whatever
This is awesome. Right now I'm trying to catch up in my Algebra class because I wasn't paying attention. This has made it, no doubt, a lot easier to do. Thank you.
did you catch up?
oh my god, thank you. I went to tutoring and they were at quadratic sketching already. You just saved my life as I had no clue what they f they were doing.
Thank you so much i have Algebra 1 regents tomorow and when i was studying i was practicing everything but quadratics because once i looked at the formula i just gave up and never understood it but today you taught me that it is not as complicated as how it looks and now i masterd it and memorized the formula in my head. And prepared for regent exam tomorow all thanks to you!
Excellent video. Just discovered the importance of the quadratic formula when trying to solve for x in a more "obvious" algebraic fashion - manipulating values on each side of equation until the variable is isolated... "Double-you tee eff broughe, why isn't this working out" - I thought. Then realized the entire expression ax^2 + bx^1 + cx^0 represents the product of two factored terms, (x + d)(x + e). This can be quite difficult to work out when a and/or b coefficients are values such as 63sin(pi/3), etc.
In these cases, where determining factors in a more basic manner is difficult, the great power of the quadratic formula is realized.
Thank you I am 9 years old and you have helped me so much
Thanks so much I kept getting my anwsers wrong because I didn't realize you had to divide both parts by the denominator.
Hows your life now?
@@akramelsayed5112 It's good about to graduate college lol.
This video is so nice because I am just learning that. I am a junior high school student in Taiwan, which is a place next to China, and I thought it was hard before, but after this video I not, this also help me with my math English, thanks for the video and the Up. Now I am going to do my math exam paper. Bye~
1 minute into the video and I already saw what I was doing wrong on all of my quadratic formula problems. tysm :D
so helpful thank you for also giving visuals on the graphing calculator for the visual learners!
He’s doing gods work by teaching me this🙏
So inspiring!! I will tell my friend Gene! And share to Churt!
You are way better than my algebra teacher thank u
Hey at least I am now learning something I will apply to two dimensional motion calculations and hopefully my future work
Thank you so much for your tutorials and your website. Also, I've watched a few other math channels and you have, by far, the best handwriting. Also, you are concientious of what the view can and cannot see (i.e.: You changing colors @2:19 ). Thank you!!!
This makes it so easy to learn quadratic formulas
This video helped me out a lot. I missed about a week of school and I came back knowing nothing until I saw this video
Btw I’m in Math Honors 8th Grade
You really teach better than my math teachers.thanks khan academy
if there are any adults here, please comment on how many times in your life you had to use this.
Never the less, this is a great tutorial; Thanks
Does using it in my maths tutorials count?? If not I’m afraid even I can’t tell you it’s vital for survival 😂
Your videos have blessed me so much. Keep up the good work.
Trust me guys in 20 years we are definetly gonna need this
Thank you 🙏 I just started school today and wanted to be ahead in my algebra class because I’m in 8 th grade and I understood what you did
thanks for helping me prep for the act.
Got this formula tattooed on my wrist today frig you forever math profs.
thank you sir! You help me a lot😁
My math teacher didn't teach this but we just started doing these problems so here I am.
Amazing... you are teaching for me... My student finally got this
school just taught me how to follow rules, this actually helped me understand it. thanks
Was so confuse and five minutes in I already understand everything love you khan academy 💕
Wow that is amazing my mark from 30-60 after study with you sir thanks
Does part one of the equation have to be squared in order for the equation to work?
thanks for the lesson, i truly appreciate how good u are at explaining these kind of stuffs such as math(lol)
Funny how we still have to learn this 10 years later
Thank You!
I can never learn from khan academy yet I still watch it
Happy to learn with you
From India🇮🇳
When I first heard about this, I thought it was going to be bloody hard, but as I started to advance study, I realized it is actually easy, though, it would if my teacher will allow us calculators for square roots😂 Thanks, Khan Academy.
I find that the equation goes quite well with the verse of Rush - Freewill
This man is an absolute legend
@13:18 if someone could explain to me where that 2 went after he divided, that would be very helpf1, thx
He simplified them by 2 to get The least of them.
Whoever said you wouldn't need this when you're older lied because today my younger sister asked for some help with Math and here I am having to re-learn what I thought I'd never need to use in the future...
I get a different answer when I use completing the square to solve it. I get 2+ or minus the square root of 13/3
thank you for explaining so thoroughly
This explained more in 5 mins then my math teacher did in 4 weeks
This may be one of the hardest I've ever learned in algebra
It gets harder
my add. maths teacher just tell us this is equal to this he doesn't explain. Thanks a lot u helped me understand the day before the exam😀
what happens if you don't get a perfect square inside the radical?
Khan academy explained to me in 15 minutes what my maths teacher couldn’t for a month
Thanks Kahn Academy this helped me a lot in math 👍🏻👍🏻
its khan im sorry i feel bad now it gave me OCD
I was trippin balls watching this and I straight up memorized it. Better than my actual Algebra class was.
thanks for teaching this, very helpful.
I study 12 years in my native Bangla Medium then switch the English thing through Khan Academy. But I feel I understand better than what I learned in Bengali Medium!
i love your voice and how it gives me ptsd
.. 💀
Where did he get the 10 from I need help please my hw is due at 12!!!!
Awesome, very helpful. Thanks.
I just learnt the song to burn it into my head, then found this so I can see it applied. Fantastic
Finnaly it makes sense
Thank you for the great video. I had a homework on this and needed urgent help. The tutor I found on Vis-a-Vis (mobile app), saved me. Best $20 spent. :)
THANK YOU, THANK YOU, THANK YOU!
When can you use the Quadratic Formula?
When the equation is in standard form
Learned more in 16 min than i did a week in algebra 1
did you also apply this formula to your inhuman experimentation, Professor Hugo Strange?!
You can learn Calculus at third grade thanks to Khan Academy just by going at a faster pace and skipping not essential school materials
how to solve a quadratic equation in a binomial form by quadratic equation
confused about where the 10 came from when he had -4+or - 10 all over 2
He took the square root of 100
Glad you asked the question I was wondering about
Please reply fast did you have to simplify that 156 or could you have just finished solving it. And why did u simplify the 156 but not the 84 from the second equation?????
I absolutely love mathematics!!! Thank you for this video! ;-)
Where did you get the 10 from?
Yeah idk where he got it from either 😢
Ever get behind class by a week and then watch one video and suddenly you're ahead by two weeks?
Haha same
13:25 new word he came up with?
I don't know who u are but you a new God to me
Christopher Power Sal Khan
THANK YOU!!!
I kinda like the way u teach cause u teach ...... I don't know its just ..... U mm understandable
Negative b plus or minus the square root of b squared minus four ac over two a. That’s insane that’s absolutely insane!
it was all good till the last question, you went to ahead and tried using different methods to get the answer and now im confused again thanks alot
so what do we do with -84? Do we not factor the coefficient? 84= 42, 2. 42= 6, 7. 6= 2, 3. therefore 2x7x3=42? and if so, where do we go from here? Do we now express the equation as -6+-2 then square root 42 and -1 all over 6, cancel the -1?
Where did you get 10 from???