Given an equation for the axis of symmetry of x = -2 and two other points on the parabola of (-5, -24) and (-1, 0), write an equation of the parabola.

Question

Given an equation for the axis of symmetry of x = -2 and two other points on the parabola of (-5, -24) and (-1, 0), write an equation of the parabola.

What is the "a" value? *

6 points

Your answer

What is the "b" value? *

6 points

Your answer

What is the "h" value? *

6 points

Your answer

What is the "k" value? *

6 points

Your answer

Write the equation for the parabola. Enter your response like this: f(x)=-5(x+7)^2+8 (Exactly like that. NO SPACES)

Answer 1

As the axis of symmetry is x = -2, the parabola may be written as

a(x+2)^2+k

As (-5,-24) and (-1, 0) are on the parabola,

a(-5+2)^2+k = -24

a(-1+2)^2 + k = 0

9a+k=-24

a+k=0

From the second equation, k = -a

9a+-a=-24

8a=-24

a=-3

k=3

y=-3(x+2)^2+3

y=-3x^2-12x-9

a=-3

b=-12

h=2

k=3

y=-3x^2-12x-9