Question

Using the direction, size and vertex of your parabola, think of a quadratic equation in general form, y = a(x - h)2 + k, that would closely match your parabola. Remember (h, k) represents the vertex of the parabola.

Answer 1

This is the picture of the parabola I am using...it's the inside of the first arch. I can't figure out what numbers to put in the equation

Answer 2

This is strange ...The only thing I can predict here is the coefficient x^2 is negative. Do you have more data?

Answer 3

No. It's part of a project that I'm doing. I know you're supposed to be using GeoGebra to have a visual representation...I just didn't know how to set up the equation. I'm under the impression that you do your best to guess an equation and see how close it is to the parabola in the picture.

Answer 4

It's alright if you don't get it. I was hoping to finish the project tonight but I can always ask my teacher on Tuesday...

Answer 5

First thing to do would be fix the origin at a convenient point.

Answer 6

Is the origin the vertex? For the vertex I got the point of (2.47, 5.24)

Answer 7

How did you get that?

Answer 8

I uI used the point finder on GeoGebra...is it totally wrong? I'm so sorry, I have no clue what I'm doing

Answer 9

I just dont have any idea I mean you just got a parabola without a coordinate axes.How are you supposed to give the vertex point?

Answer 10

THe parabola is the McDonald's arch...right? That's what I thought the picture was for

Answer 11

yes it is.

Answer 12

Are you given the dimensions or something?

Answer 13

The dimensions?

Answer 14

like the length of the mcdonald part or sthng.

Answer 15

Ah, no. I put the picture in GeoGebra, which is basically like putting the picture on an actual graph...I could use a different picture?

Answer 16

I see. All the best sorry I dont know how to help you on this.

Answer 17

It's alright. Thank you for trying :)

Answer 18

My initial thought was to use GeoGebra. Import the gif you have into GeoGebra and use the Parabola tool to select the point and directrix. Then use the "Focus" command and the "Vertex" command to find the focus and vertex. Then use the "Distance" command to find the distance between the focus and vertex to use for P in the equation below. With the vertex command, you will also have h and k:
\(\Large y={(x-h)^2\over 4p}+k\).
I get for h, p and k:
\(\Large y={(x-2.97)^2\over 4(-.13)}-0.49\)

http://en.wikipedia.org/wiki/Parabola

http://www.wolframalpha.com/input/?i=y%3D-%28x-2.97%29^2%2F%284*0.13%29+-0.49

Answer 19

Let me know if you have any questions.