Another way to do this is to set Y = a(X-b)(X-c) and find a, b and c. Note that if X= b and/or X = c we have Y = 0. So take b = 1 and c = -5 and you end up with Y = a(X-1)(X-(-5)). In order to find a you should require that one of the points (0,5) or (-2,9) is on the graph. Substitue for X = 0 and Y = 5 and you see that 5 = a(-1)(5) or 5 = -5a. This gives you a = -1. The equation is Y = - (X-1)(X+5). This, of course, is identical to the solution in the video.
What if the prabola we are dealing with has no X intercept or only one? Is there any direct way like this one u wrote to get the standard ax^2 + bx + c ? Or do we have to open and solve the form shown in vid?
Thank you. I know you produced this video 6 years ago and your teaching skills have improved immeasurably. However, I think it would have been helpful if you explained that you tackled the problem initially by completing the square, as most of us would be more familiar with this approach when asked to write down the equation, given the turning point/vertex (or vice versa). Otherwise, well done and keep up the good work.
QWERTY was a great night out of the way we got it one day and I got a good day and a good up way too long haha is that a big deal to get a little more than
vertex is [-2 , 9] (v = h , k) y intercept is [0 , 5] x intercepts are [- 5 , 0] and [1 , 0] We have a "frowning" parabola. so we know that a is of a negative value So the vertex formula is y = -1(x+2)² + 9 (vertex form is y = a(x-h)² + k) The quadratic formula is y = -x² - 4x + 5 We know the a term is -1 because of the formulas x = h + √(-k/a) and x = h - √(-k/a) so lets prove it: x = -2 + √(-9/-1) negative divided by negative is positive so that means √9 which is 3 so x = -2 + 3 and x = -2 - 3. or the x intercept is the xy coordinate [1 , 0] and [-5 , 0] which is true for both cases. now prove the quadratic form: -1(x+2)(x+2) + 9. gives us -1(x² + 4x + 4) + 9 which finally is -x² - 4x -4 +9 or -x² -4x + 5 In order for there to be x intercepts the k term MUST be either the opposite sign of the a term OR k must equal 0. (otherwise you are taking the square root of a negative number. imaginary is ok for solving the equation, but it does not translate to the graph and it shows there is no x intercept) Made a couple mistakes and only caught them because I proved my equations. Always prove and show your work. If your teacher is worth their salt they will see where you are coming from and may advise you of where you messed up. Anyways it has been a long time since I've done this stuff and I only do them for fun to keep my brain sharp.
Wait, my teacher said that you cannot have a negative sign of the value of a, but if it is negative sign, you need to change the sign of all value. Im so confused 😭🙏 Please answer
For more algebra tutorials, please see my new channel "Just Algebra" bit.ly/just_algebra
You covered more in this video than my math teacher does in a full hour and a half 😂
Strait facts
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I wish this man taught all my classes
As a parent trying to assist her online math learning 7th grader THANK YOU! Your explanation was perfect and you showed every step.
what kinda 7th grader learning this
@dadaveed4272 Lol, we listen and we don't judge
Your dexterity at the white-board is phenomenal and your explanation is clear, concise and completely convincing: thank you.
thank you so much, you explained it so much better than my actual math teacher:)
This is the first person I've known who does 7 hours of math on there bday.
Very Helpful! I think this is exactly what I've been trying to figure out, and it was explained very well!
Thank you so much! This was very helpful and your explanation was very easy to follow!
I'M NOT EVEN JOKING. I HAD AN ASSIGNMENT DUE AT 12 AND THANK YOU THANK YOU FOR HELPING ME UNDERSTAND THIS STUFF lol
Thank you very much! I was struggling with my physics homework because I forgot how to write the equation of a parabola. This really helped me. :))))
Thank you this was very helpful, especially when you explain where the numbers came from when writing the equation itself at the end.
Another way to do this is to set Y = a(X-b)(X-c) and find a, b and c. Note that if X= b and/or X = c we have Y = 0. So take b = 1 and c = -5 and you end up with Y = a(X-1)(X-(-5)). In order to find a you should require that one of the points (0,5) or (-2,9) is on the graph. Substitue for X = 0 and Y = 5 and you see that 5 = a(-1)(5) or 5 = -5a. This gives you a = -1.
The equation is Y = - (X-1)(X+5). This, of course, is identical to the solution in the video.
k
What if the prabola we are dealing with has no X intercept or only one? Is there any direct way like this one u wrote to get the standard ax^2 + bx + c ? Or do we have to open and solve the form shown in vid?
This covered everything I tried learning for the past hour 😂.
this came in clutch, i literally have an exam about this in like no time
You taught me more in 4 minutes than my teacher could in four days, thank you so much
I was struggling to understand the material until i found this video, thanks a lot 😂🙏🏽
thank you for the basic break down, you simplified it more that all my teachers did through high school.
bro this guy is so good, i literally learned so much and he is such a great teacher, keep up the amazing work dude
Thank you. I know you produced this video 6 years ago and your teaching skills have improved immeasurably. However, I think it would have been helpful if you explained that you tackled the problem initially by completing the square, as most of us would be more familiar with this approach when asked to write down the equation, given the turning point/vertex (or vice versa). Otherwise, well done and keep up the good work.
broo this man makes it look sooo EAASY.. And my teacher em doing some calculas type of shit to find the vertex.. LOL
my teacher has been teaching this for 2 days but I understand it nowthanks to this 6 minute video 😂😂
excellent, simple and smart explanation.
Thanks very much..your explanation is very very clear ❤
thank you so much you saved my life bless you
engaging and interactive, man is a literal chad
srsly thank you so much, i was having such a hard time understanding, and i understood perfectly in this video
Thank you so much for this lesson, it helped me so much and I could understand everything perfectly
Thank you!!! I have a unit math test tmr and didn’t understand nothing but now I will do great🙏🏽
bro, I have been struggling to solve these damn problems, but you saved me!!!!!!!
I never thought I'd be using parabolas to optimize my builds in a video game, but here I am, lmao.
HE USED A BLUE PEN
I enjoyed your solution, thank you!
great work my man, u helped me a lot, keep up the good work!
Thank you so much this really helped me with my math
Thanks you answered all the questions I had about this without having to struggle to raise my hand
omg I was the 1500 like exactly and this video was super helpful I understood it super well thanks to the video
This was SOOO HELPFULL
Thank you so much man, this is very clutch
Super helpful video. Thanks a ton!!!!
Hipppity hoppity I took my moms credit card
QWERTY was a great night out of the way we got it one day and I got a good day and a good up way too long haha is that a big deal to get a little more than
Thank to so much for this explanation!! 🙌
Thank you, great explanation.
he taught it less than 10 minutes
amazing!
Thank you so much this was so helpful.
Very clear! Thanks mate
thank you so much. Its very helpful
this guy is straight up cooking
U made this so easy thanks keep it up
thank you, u helped me alot
Hello , thank you so much for the help man
If we are not given the points on y axis then how can we make the equation..?
i would die for this man
Awesome video helped a lot
Thank you man, Sincerely.
Thank you man❤
Thank you so much, you saved me man
It might just be me but, why is his voice so stimulating?!?!?
THANKK YO SOO MUCH. ITS D LAST DAY OF OUR DEADLINE. AND THANKZZ TO U SIR, I FINALLY UNDETSTOOD IT.
Thank You !!!
vertex is [-2 , 9] (v = h , k)
y intercept is [0 , 5]
x intercepts are [- 5 , 0] and [1 , 0]
We have a "frowning" parabola. so we know that a is of a negative value
So the vertex formula is y = -1(x+2)² + 9 (vertex form is y = a(x-h)² + k)
The quadratic formula is y = -x² - 4x + 5
We know the a term is -1 because of the formulas x = h + √(-k/a) and x = h - √(-k/a)
so lets prove it: x = -2 + √(-9/-1) negative divided by negative is positive so that means √9 which is 3
so x = -2 + 3 and x = -2 - 3. or the x intercept is the xy coordinate [1 , 0] and [-5 , 0] which is true for both cases.
now prove the quadratic form:
-1(x+2)(x+2) + 9. gives us -1(x² + 4x + 4) + 9 which finally is -x² - 4x -4 +9 or
-x² -4x + 5
In order for there to be x intercepts the k term MUST be either the opposite sign of the a term OR k must equal 0. (otherwise you are taking the square root of a negative number. imaginary is ok for solving the equation, but it does not translate to the graph and it shows there is no x intercept)
Made a couple mistakes and only caught them because I proved my equations. Always prove and show your work. If your teacher is worth their salt they will see where you are coming from and may advise you of where you messed up.
Anyways it has been a long time since I've done this stuff and I only do them for fun to keep my brain sharp.
I'm kinda confused if you don't know the number for h (x coordinate for the vertex). How would you complete the vertex formula?
Use the parabola formula (y-k)^2=x-h with the input your teacher gives u the h& k will be ur vertex points
I have similar questions like this. But the turning point (vertex) is not given. How can I find that without the equation only from the graph?
Good job 👍👏
sir, you save my life. I appreciate your video hahaha.
Thankyou soo much 😢💖
thank you very much dude
Thank you broo
In the beginning I wasn’t understanding and in the end it seemed like I was in the beginning
super helpful. thank you.
Thanks
thank you sir
Yes but in the case that I have the equation but not the parabola what can I do??
i'm gonna pass my exam, ToT, thank you so much 😊
Thanks man!
Thank you!
mans marker switching skills tho😹😹 But well explained m8🙌🏽🙌🏽
Thank you so much
THANKYOU SO MUCH!!
what if the graph doesn’t give you the vertex value?
In Search of gold I got diamond
Super
Helpful
thanks man got it very well
amazing ! tysm :D
THANK YOU sooooo much you just helped me not be screwed on my math project🫡
My good sir thank u so much
can I use f(x) instead of y?
thank you!
Man Is literally giving me 5 head math power
thank you
thank you very much and how could one get the focus and the directrix from an equation in vertex form
Damn i met this question a while ago and i used my own method which was to multiply (x+5) with (x-1) to construct the quadratic equation
Thank you! Gracias
Bringing me out the mud fr
awesome 👍
Thank you so much 😊
AWESOME!!!!!!!
The best!
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Wait, my teacher said that you cannot have a negative sign of the value of a, but if it is negative sign, you need to change the sign of all value. Im so confused 😭🙏 Please answer