Question

Please help me with this..

When given the vertex and the y-intercept of a parabola, use this vertex form of the equation to find the value for a and the final equation :

(y-k)=a(x-h)^2

Find the equation of the parabola with vertex (1,-108) and y-intercept (0,-5). Write your answer in vertex form. And PLEASE SHOW ALL YOUR WORK.

Answer 1

Plssss help

Answer 2

@AlexisDeniseBurns You'll need to come back online to help with this.

Answer 3

I'm online

Answer 4

Okay. We will get started.

Answer 5

(y-k)=a(x-h)^2

(h,k) in the formula is for the vertex of the parabola.

The vertex is given as vertex (1,-108)

Answer 6

In this equation, substitute:

1 for h

-108 for k

and post what you get when you do that, okay?

Answer 7

(y--108)=a(x-1)^2

Answer 8

Which gives:

(y+108)=a * (x-1)^2

Answer 9

Yeah I understand

Answer 10

The parabola has y-intercept (0,-5).

The y-intercept is a point on the parabola.

Answer 11

Take this (y+108)=a * (x-1)^2

and replace

x by 0

and

y by -5

Post what you get when you do that, okay?

Answer 12

(-5+108)=a * (0-1)^2

Answer 13

(-5+108)=a * (0-1)^2

103 = a* (-1)^2

103 = a*1

103 = a

Do you agree?

Answer 14

I agree

Answer 15

The last task is to write the equation of the parabola in vertex form.

Answer 16

Go back up the thread to the equation you wrote with the coordinates of the vertex.

(y+108)=a * (x-1)^2

Answer 17

We know now that a = 103

Answer 18

So, what is the final answer for the equation of the parabola in vertex form?

Answer 19

Take this and replace a with 103.

(y+108)=a * (x-1)^2

Answer 20

(y+108)=103*(x-1)^2

Answer 21

Is my final equation (-5+108)=103(0-1)^2

Answer 22

The vertex form for a parabola is this: y=a(x-h)^2 + k.

Your question gives this as the vertex form of a parabola: (y-k)=a(x-h)^2

The answer will be this according to your question: (y+108)=103*(x-1)^2

Or, according to the definition of vertex form given elsewhere,

y=103*(x-1)^2 - 108

Answer 23

I would go with this because it is in what I learned as the vertex form of a parabola:

y=103*(x-1)^2 - 108

Answer 24

Which one is my final equation and which one Is the equation of the parabola

Answer 25

But, look in your text to see what is given to be the vertex form of a parabola.

From your question, it appears that this would be the answer for this question:

(y+108)=103*(x-1)^2

Answer 26

>>Is my final equation (-5+108)=103(0-1)^2

No.

Answer 27

What exactly should I write on my paper, that would answer all that the question is asking

Answer 28

(y-k)=a(x-h)^2

(h,k) in the formula is for the vertex of the parabola.

The vertex is given as vertex (1,-108)

(y+108)=a * (x-1)^2

The parabola has y-intercept (0,-5).

The y-intercept is a point on the parabola.

(-5+108)=a * (0-1)^2

103 = a* (-1)^2

(y+108)=103*(x-1)^2

103 = a*1

103 = a

Answer 29

Thank u SOOOOOOOOOOOOOO much

Answer 30

You are welcome.