I hate to say that my maths teacher is horrible, thank you for this tutorial because now I can finally understand parabolas! You taught me more than a few hours of maths at school.

24hancock, this dude does have a life, and it is to teach others about information that they need for school or college. He is helping a lot of people right now do better In school and is giving millions a better understanding of education. So tell me, how are YOU helping in life?

THANK YOU KHAN

this made so much sense! you have an incredible knack for explaining extremely clearly in the most concise way, thank you so much!

I like his way allot better than the way my teacher explained it.

@pilko11 No, it's -25. -X^2 means it's the negative of X^2, so the minus sign is not part of the term being squared. If the minus sign WAS part of the square it would look like this (-X)^2. I hope that helped ya out.

Thanks khanacademy!

I love the way you teach things - school teachers should learn from you!

then use the quadratic formula: -b + or - radicand b^2 -4ac all over 2a. It always works whereas factoring does not.

Thank you very very much!

this helped a lot

that helped alot

Thank you Khan Academy

Thanks a lot! I understand it better than my math lessons

My math teacher didn't teach us to factor it, he just showed us the formula for a quadratic function (y = ax^2 + bx + c) and then the formula for finding the vertex point (-b / 2a). And then you would plug in that for x in the equation to get y. I'm thinking the one I was taught is simpler.

Brilliant teaching skills...thank you

Thank you, this helped with my algebra homework. (Yes, I go to a class in the summer to have a head start on Algebra 1). -.-

He says the axis of symmetry is the average of the x-intercepts. well say that you have two x-intercepts; one is -4 and the other is +2. The halfway mark between those is -1, so your axis of symmetry is -1. The axis of symmetry is simply the x-coordinate of your vertex. Hope I helped.

thank you ^^

hit the Khan

BAM!

thank you! still kinda iffy bout it but way better than my teacher -___-

great (Y)

You made it soooooooooooo simple. My teacher may it look like it was japanese to me

greaaaat

I don't understand why do I have to do this, if I can graphic a quadratic function by the easy way, we're I give 'x' a value. Or this is just used when I have a coefficient in the middle term?

8:15 nice ringtone .

Im just wondering with this quadratic equation: ax^2+bx+c As c is -8, doesn't that mean the parabola also intersects the y-axis at -8?

nice

3:07 a fly passed by

why did you ignore the 2 in example (ii)

hey where does the -1 coefficient go in the last example

i need help on the (fx+g)(hx+j)

I'm 10 and I'm doing this kind of Mathson

Your a genius.

@AhmadMakari

10 жыл бұрын

*You're. Apparently, you are not.

@allenspacer5345

10 жыл бұрын

Ahmad Makari What a rude thing to say. Let me ask you, have you ever made a grammatical error on youtube before? (be honest). I'm pretty confident you have, would it be right for me to judge your intellect based on that? I certainly don't claim to be a genius, but even they make mistakes. I've seen khan make mistakes several times while doing his work, so be careful the sort of things you say to people on youtube.

@AhmadMakari

10 жыл бұрын

***** Are you kidding me? Do you actually think I was being rude and serious? It was just a joke dude, so calm the fuck down.

@allenspacer5345

10 жыл бұрын

Ahmad Makari You were kidding? Sure

@Procrastinerd

9 жыл бұрын

***** Take your own advice - I have mild autism!

@24hancock go watch his segment on CNN

BAM just like like that :D

sorry but i don't understand when he says the vertex is the average of the x-intercepts. what is the exact formula?

why didnt you just used -b/2a to find the vertex?

isnt -5^2 = to 25 not -25?? 14:06

the way i learned to find the vertex was -b divided by 2(a) so some of this explanation confuses me... help?

@CloudGOML

8 жыл бұрын

+Chance Miller Yeah, you can do it that way as well. You can also complete the square to find the vertex coordinates. In y= x² -2x -8, a=1 b=-2 and c=-8, so you can just use the formula that you mentioned x=-b divided by 2(a), and substitute in those values. That will give you the x coordinate of the vertex, and then you can take the x coordinate of the vertex and put it in y= x² -2x -8, which will give you the y coordinate of the vertex. I know this explanation probably doesn't help you since you asked 3 weeks ago, but oh well lol.

@ChanceUriahMiller

8 жыл бұрын

Rudy Steiner thanks for the help anyway and yes it was three weeks ago but it will still help me as a reminder when the finals come up so it does help. thank you

My math teacher makes it look like rocket science. And he says it's easy. :I

its only 25 when its (-5)^2

Im so confused

@frbinuthomas5400

9 жыл бұрын

Coco louis Do you play Roblox? And this is NOT confusing to me.

@24hancock you obviously have no clue who this guy is LOL