This is really helpful! It’s so easy to zone out when my teacher is explaining stuff- she talks about really random stuff building up, and won’t get to the point for a while
Thank you so much, I finally found a video where the person was good at explaining the concept of this topic and how well you conveyed it to the audience. Thumbs up for you!
Thanks, man. Solid teaching. Just a question if you are able to answer it. Why does equation 2 and 3 given at the start always show in brackets (X - constant), why is it always minus and never plus? I think I may know the answer intuitively it looks like it's related to transformations, i.e. when you move a graph in the X direction by amount '+d', the equation changes by (X-d) and so on. Think I may have answered my own question typing my thoughts lol, but some confirmation/guidance would be extremely useful. Thanks dude and great video!
I have three kids doing Junior High and High School math remotely. I watch a lot of math videos with varying degrees of complexity. This one seems a trifle challenging, particularly in the way he works so quickly. I'll file this video for future use when my Algebra skills are a bit stronger. Having said that, there's some valuable info in this video.
Find the x value of the maximim/minimum by x = -b/2a (or half way between the 2 roits) and then put that value back into the original y=,,, or f(x) =,,,,, equation
Go to 4:46 in the video. This example has the vertex and the y-intercepts. With x-intercepts you do the same thing; just choose one of the x-intercepts and sub it in the equation to solve for a.
In the equation y = a (x - p) (x - q) , you can replace p and q with the x-intercepts. But you will still have an equation that relates x to y. For example, if your equation is y = (x -2)(x - 1), you can rearrange that to y = x^2 - 3x + 2, so any point (x, y) on the graph will satisfy this equation, i.e. make the equation true. I hope this answers your question.
As long as they give you one put on the graph, you can still substitute in these values for x and y into your equation. This will enable you to work out the value of a, the leading coefficient.
What if i just have the graph and the (h, k)? WHat other info can I pull of the graph? My y intercept is a repeating decimal. Same with my p and q. I have AN equation, but it isnt in any proper form, and i cant fix it. 12y=(x-1)^2 -48. Its in the one form but with the extra number on the side. what should i do? I need to find my focus and directrix for my question.
You can rewrite the equation as y = 1/12 (x - 1)^2 - 4 , by dividing both sides by 12. If you make x = 0, you will find that the y-intercept will be 1/12 - 4 = - 3.9166667 or -3 11/12. To find the focus and directrix you need to rewrite your equation in the form 4p(y - k) = (x - h)^2, which in this case will be 12 (y + 4) = (x - 1)^2 . (h, k) is still the vertex, so in this case the vertex is (1, -4). The parameter p is called the focal length, so in this case p = 12/4 = 3. Therefore, the focus is (1, -1), which is 3 up from the vertex, and the directrix is y = -7, which is 3 down from the vertex. The focus / directrix question is really different from the usual equation of a parabola questions. I suggest searching for another video to get in more depth for this, or if you just need the answer for one question use a calculator like the one on this site, www.symbolab.com/solver/parabola-directrix-calculator/.
The value of b is a little harder to understand than the other letters. If b is negative, it means the vertex of the graph will be on the positive side (i.e. right of the y-axis); if b is positive, it means the vertex is on the left of the y-axis. But, it is probably more useful just to remember that the vertex is where x = -b/(2a). This is why it is useful to rewrite the equation in different formats; because the different formats give you different information.
If the question doesn't give you one of the specific points (like c, or p or q or h or k), but they do give you another point, you can sub the x and y values from that point into your equation and solve for c. The whole principle is, there are three unknowns, a, b and c. So we need three points to solve for them, unless they give us a special point like the vertex. Good luck.
This is really helpful! It’s so easy to zone out when my teacher is explaining stuff- she talks about really random stuff building up, and won’t get to the point for a while
Thank you so much, I finally found a video where the person was good at explaining the concept of this topic and how well you conveyed it to the audience. Thumbs up for you!
studying for a test and this was really helpful - thankyou!!!
My test is tomorrow morning and I feel way more confident now, thanks!
My teacher doesnt really like to teach stuff so this helped a lot
Thanks, man. Solid teaching. Just a question if you are able to answer it. Why does equation 2 and 3 given at the start always show in brackets (X - constant), why is it always minus and never plus?
I think I may know the answer intuitively it looks like it's related to transformations, i.e. when you move a graph in the X direction by amount '+d', the equation changes by (X-d) and so on.
Think I may have answered my own question typing my thoughts lol, but some confirmation/guidance would be extremely useful.
Thanks dude and great video!
this is exactly what i needed took me ages to find a video like this THANK YOU
welp im going to get 0% and be homeless forever
update: I did fail i got a no award
What a douche
You are
Update: you realize you suck at maths.
@@Shannon-l1h indeed
f in the chat
I have three kids doing Junior High and High School math remotely. I watch a lot of math videos with varying degrees of complexity. This one seems a trifle challenging, particularly in the way he works so quickly. I'll file this video for future use when my Algebra skills are a bit stronger. Having said that, there's some valuable info in this video.
Thank you for this video, it helped me a lot
LOVE YOU FROM PAKISTN.
thanks you very much.
make these kind of Videos for us
poor in both background like
in money and average in math..
I completely understand now🙏🏾 thank you so much.
Lifesaving video, thank you
Thank you so much for making this video!! So helpful.
What if their is no Y int
What if you are not given the y intercept but you are given a point on a curve
for the last example how did u get a=2 and a=-3?
Thank you! This was very helpful!
what if you don't know what c is?
What will I do to find the y maximum value of the parabola?
Find the x value of the maximim/minimum by x = -b/2a (or half way between the 2 roits) and then put that value back into the original y=,,, or f(x) =,,,,, equation
3:55 made everything make sense to me
Great video really luv it!
Does anyone know if this is on the GCSE spec?
Fantastic, cheers matey.
Thank you so much this really helped
this is so good, finally I understand, very grateful, thanks
stfu no one cares about your robot fan-fiction. Stay in your place. *TRASH*
Thank you so much!
Thanks a lot mate, really very helpful.
What when you don’t have the y intercept
Yes but you are missing the method for when you know the vertex but you don't know c which was an actual question this year on paper 1 AI SL
Amazing!!! The best!!!!
Thank you. Appreciate it
Thank you so much, I might not fail IB math because of you!
Ranya Dubai?
how di you find "a" given the x intercepts and vertex
Go to 4:46 in the video. This example has the vertex and the y-intercepts. With x-intercepts you do the same thing; just choose one of the x-intercepts and sub it in the equation to solve for a.
how did u get 4x in the second example
Foil out the two brackets you get -2 (x^2 - 2x - 3)
Then multiply each term by -2; you get -2x^2 + 4x + 6
If p and q= x intercepts what is x in the equation then?
In the equation y = a (x - p) (x - q) , you can replace p and q with the x-intercepts. But you will still have an equation that relates x to y. For example, if your equation is y = (x -2)(x - 1), you can rearrange that to y = x^2 - 3x + 2, so any point (x, y) on the graph will satisfy this equation, i.e. make the equation true.
I hope this answers your question.
Y= a(x-p)+(x-q), where p and q are zeroes of the quadratic polynomial,
Another
Y= ax^2+ bx + c
And another
For completing the square,
P+q /2.
Thank you! Very helpful :)
For the second example, Im confused as to how u got a=-2, my exam is tomorrow, can u plz reply quickly
Divide the 6 by -3 which = -2
@@jadenwilliams2996 thank u so much! Shuldve known that, quite simple.
👍
Thank you so much.
How about graphs that do not show where is the y-intercept?
As long as they give you one put on the graph, you can still substitute in these values for x and y into your equation. This will enable you to work out the value of a, the leading coefficient.
Thank you!
Wow! Thanks a lot
Very helpful
What if i just have the graph and the (h, k)? WHat other info can I pull of the graph? My y intercept is a repeating decimal. Same with my p and q.
I have AN equation, but it isnt in any proper form, and i cant fix it. 12y=(x-1)^2 -48. Its in the one form but with the extra number on the side. what should i do? I need to find my focus and directrix for my question.
You can rewrite the equation as y = 1/12 (x - 1)^2 - 4 , by dividing both sides by 12. If you make x = 0, you will find that the y-intercept will be 1/12 - 4 = - 3.9166667 or -3 11/12.
To find the focus and directrix you need to rewrite your equation in the form 4p(y - k) = (x - h)^2, which in this case will be 12 (y + 4) = (x - 1)^2 . (h, k) is still the vertex, so in this case the vertex is (1, -4). The parameter p is called the focal length, so in this case p = 12/4 = 3. Therefore, the focus is (1, -1), which is 3 up from the vertex, and the directrix is y = -7, which is 3 down from the vertex.
The focus / directrix question is really different from the usual equation of a parabola questions. I suggest searching for another video to get in more depth for this, or if you just need the answer for one question use a calculator like the one on this site, www.symbolab.com/solver/parabola-directrix-calculator/.
I'm pretty sure you would have to divide 12 on both sides
What does b mean
The value of b is a little harder to understand than the other letters. If b is negative, it means the vertex of the graph will be on the positive side (i.e. right of the y-axis); if b is positive, it means the vertex is on the left of the y-axis.
But, it is probably more useful just to remember that the vertex is where x = -b/(2a).
This is why it is useful to rewrite the equation in different formats; because the different formats give you different information.
Relearning to teach my girlfriend, helped a bunch
Thanks
THANK YOU SO MUCH
THANK YOU!!!!!!!!
What if u don’t have c
If the question doesn't give you one of the specific points (like c, or p or q or h or k), but they do give you another point, you can sub the x and y values from that point into your equation and solve for c.
The whole principle is, there are three unknowns, a, b and c. So we need three points to solve for them, unless they give us a special point like the vertex.
Good luck.
what is a i dont get the point in it
a is the stretch value.
a fucking hero
you left out the most important part
Most monotone and hard voice to follow thanks I guess.....
lol
Thank you!!!
Good...
I didn't understand anything
2nd one is wrong, should be -2x²-2x-3. Still an excellent video
No, it's correct.
y = -2 ( x + 1)(x - 3) = -2(x^2 - 3x + 1x - 3) = -2(x^2 - 2x - 3) = -2x^2 + 4x + 6
Also check by actually graphing
My name chef
goat
Rip my ears
Why ?
you don’t explain anything