Finding the equation of the graph of a parabola

[@adaidhfitz]

welp im going to get 0% and be homeless forever update: I did fail i got a no award

[@vineparadise1368]

What a douche

[@vineparadise1368]

You are

[@Shannon-l1h]

Update: you realize you suck at maths.

[@adaidhfitz]

@@Shannon-l1h indeed

[@lackofplethora7065]

f in the chat

[@slugcat9467]

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

[@irenepopan1217]

studying for a test and this was really helpful - thankyou!!!

[@captaingum-gumboi6936]

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!

[@j1m0thy]

3:55 made everything make sense to me

[@lukeh9300]

My teacher doesnt really like to teach stuff so this helped a lot

[@jackwalton6657]

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!

[@Ninja-wz4vy]

What if their is no Y int

[@lukeh9300]

My test is tomorrow morning and I feel way more confident now, thanks!

[@Varshi-o7w]

Thanks

[@syedaliahmedshahgardazi]

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..

[@noracream2997]

what if you don't know what c is?

[@jaykaysdimple9718]

I completely understand now🙏🏾 thank you so much.

[@michaeltaylor1788]

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

[@Varshi-o7w]

Thank you for this video, it helped me a lot

[@boxadorsrus5991]

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.

[@pareetaagrawal8451]

Thank you so much for making this video!! So helpful.

[@MrMrmattisonfire2]

Thank you! This was very helpful!

[@davidclarke717]

Thank you so much!

[@philipolivier1133]

this is exactly what i needed took me ages to find a video like this THANK YOU

[@peeepoi1395]

I didn't understand anything

[@tizuhakiki1897]

Thank you. Appreciate it

[@vincenttapal6826]

What will I do to find the y maximum value of the parabola?

[@mrhallatwork]

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

[@christinelin9331]

a fucking hero

[@hamdi.mohamed]

Thank you so much.

[@seanleysinday9120]

Wow! Thanks a lot

[@simmicubes5414]

Great video really luv it!

[@notericok7695]

Thank you so much this really helped

[@lifeadventures4733]

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.

[@HelloThere-xx4nx]

Lifesaving video, thank you

[@gladysmbukwa4010]

What if you are not given the y intercept but you are given a point on a curve

[@Unknown-ek4cy]

for the last example how did u get a=2 and a=-3?

[@boyitsame]

you left out the most important part

[@lackofplethora7065]

Does anyone know if this is on the GCSE spec?

[@diegobustamante5701]

What when you don’t have the y intercept

[@cumarcarafad2748]

Rip my ears

[@avalonase6356]

Why ?

[@joshdawson6639]

Thank you! Very helpful :)

[@colbyreed5425]

Relearning to teach my girlfriend, helped a bunch

[@UNCOVR]

Fantastic, cheers matey.

[@sehrishkamran994]

Amazing!!! The best!!!!

[@ranyazarabimbrahw2187]

Thank you so much, I might not fail IB math because of you!

[@celation2378]

Ranya Dubai?

[@nellasa.3551]

Very helpful

[@22jeffstreet11]

My name chef

[@PAWNB3YOND]

THANK YOU!!!!!!!!

[@lucymitric2325]

THANK YOU SO MUCH

[@farukyimljuchowdhury8471]

If p and q= x intercepts what is x in the equation then?

[@roberthall2681]

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.

[@bkgsimp9647]

how di you find "a" given the x intercepts and vertex

[@roberthall2681]

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.

[@eileenjoy8139]

how did u get 4x in the second example

[@roberthall2681]

Foil out the two brackets you get -2 (x^2 - 2x - 3) Then multiply each term by -2; you get -2x^2 + 4x + 6

[@Wyatt5704]

What if u don’t have c

[@roberthall2681]

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.

[@joejvaisey]

what is a i dont get the point in it

[@tehgundulf]

a is the stretch value.

[@jackmilewczik7952]

What does b mean

[@roberthall2681]

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.

[@shungokusatsu1181]

Most monotone and hard voice to follow thanks I guess.....

[@adrianberdecia4489]

lol

[@stivenvigil4426]

How about graphs that do not show where is the y-intercept?

[@roberthall2681]

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.

[@stivenvigil4426]

Thank you!

[@vineparadise1368]

Thanks a lot mate, really very helpful.

[@stephenmorris3696]

this is so good, finally I understand, very grateful, thanks

[@adrianberdecia4489]

stfu no one cares about your robot fan-fiction. Stay in your place. *TRASH*

[@asmaahmad4721]

For the second example, Im confused as to how u got a=-2, my exam is tomorrow, can u plz reply quickly

[@jadenwilliams2996]

Divide the 6 by -3 which = -2

[@asmaahmad4721]

@@jadenwilliams2996 thank u so much! Shuldve known that, quite simple.

[@jadenwilliams2996]

👍

[@retartit]

2nd one is wrong, should be -2x²-2x-3. Still an excellent video

[@roberthall2681]

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

[@ocenite6335]

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.

[@roberthall2681]

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/.

[@farukyimljuchowdhury8471]

I'm pretty sure you would have to divide 12 on both sides

[@alduraplayz8457]

Thank you!!!

[@mattjohnson7104]

goat

[@valw1535]

you don’t explain anything

[@srinumerigi3548]

Good...