Please Help with this prob

[moronatmath]

Can someone please help me out with this problem?


Find a function whose graph is a parabola with vertex (1,-12) and that passes through the point (2,-9).

f(x) =?

 

[tkhunny]

Find a function whose graph is a parabola with vertex (1,-12) and that passes through the point (2,-9).

Parabolas have symmetry. There is an axis running through the vertex. It's called the "Axis of Symmetry".

If the Vertex is at (1,-12), and there is a point at (2,-9), you have insufficient information to write the equation of a unique parabola. There are infinitely many!

However, since the problem statement says "Find a function", we know that the Axis of Symmetry is vertical. This means, by symmetry, that there is another point, (0,-9). This additional insight gives sufficient information for a unique definition.

 

[moronatmath]

Very informative and I appreciate that! How would I go about writing up the formula?

 

[tkhunny]

You're really not being very helpful. You need to demonstrate some ability to do something.

Do you know what the equation of a parabola looks like? If you do, you haven't told us.

Do you know how to substitute ordered pairs into an equation with arbitrary coeficients? If you do, you haven't told us.

Can you solve a few suffiently defined simultaneous equations? If you can, you haven't told us.

You MUST start showing some work or there's really nowhere to go.

 

[moronatmath]

I have never done any kind of problem like this. I figured there is a formula or something that I need to plug in to do the problem. This is why I have not done any work and am asking for some help tk.

 

[moronatmath]

You're really not being very helpful. You need to demonstrate some ability to do something.

Do you know what the equation of a parabola looks like? If you do, you haven't told us.

A parabola looks like a U on a graph.

Do you know how to substitute ordered pairs into an equation with arbitrary coeficients? If you do, you haven't told us.

Honestly, I do not know how to substitute ordered pairs into an equation with arbitrary coeficient.

Can you solve a few suffiently defined simultaneous equations? If you can, you haven't told us.

I am not sure if I can or not. So I guess that would be a no as well.


You MUST start showing some work or there's really nowhere to go.

[/quote]

 

[tkhunny]

I have never done any kind of problem like this. I figured there is a formula or something that I need to plug in to do the problem. This is why I have not done any work and am asking for some help tk.

So? Do you have a book? Why are you studying this material? Are you SURE you've had all the prerequisites?

Everyone here would love to help you, but so far you don't seem to be getting anywhere. The most likely diagnosis, in my view, is that you need a thorough local assessment to see what class you SHOULD be in. I'm thinking it isn't the one you are in. Anyone with a screen name like that really ought to rethink one's direction. We can answer questions until everyone's cows come home. If you don't start to get it, which thing you have not shown, then it is all a waste of everyone's time, including yours.

If you are a "moron at math", simply back up until you find material with which you are comfortable. In that material, you don't have to be a "moron at math". You can start knowing and quit guessing. You can challenge yourself one course at a time. It simply is foolish to skip three courses. They are taught in sequence for a reason.

Wish I Could Help,

 

[stapel]

I have never done any kind of problem like this.

They haven't covered parabolas or quadratics yet in class...?

I do not know how to substitute ordered pairs into an equation with arbitrary coeficient.

This would have been covered a course or two ago. You might want to speak with your counsellor about dropping back, so you can learn the prerequisite content. Then this stuff won't seem so mysterious.

Eliz.

 

[skeeter]

have you seen this equation before? ...

f(x) = a(x - h)^2 + k