Question

The parabola starts at left parenthesis 1 comma 0 right
parenthesis and passes through left parenthesis 2 comma 5
right parenthesis to its vertex at left parenthesis 5 comma 10
right parenthesis. It continues through left parenthesis 8 comma
5 right parenthesis and ends at left parenthesis 9 comma 0
right parenthesis. All values are approximate.
The graph shows the trajectory of a firework. Which equation in
vertex form matches this graph?
(1 point)
y = − + 10
1
2
(x − 5)
2
y = + 10
1
2
(x + 5)
2
y = − − 10
1
2
(x − 5)
2
y = + 10

Answer 1

Vertex form: y = a(x − h)^2 + k with vertex (h,k) = (5,10), so y = a(x − 5)^2 + 10. The parabola opens downward, so a < 0. The matching choice is

y = −(1/2)(x − 5)^2 + 10.