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=−12(x−5)2+10


y=12(x−5)2+10


y=−12(x−5)2−10


y=12(x+5)2+10

Answer 1

y = −12(x − 5)^2 + 10

Reason: Vertex form is y = a(x − 5)^2 + 10 (vertex (5,10)). The parabola opens downward, so a < 0; the only choice with that vertex and a negative a is y = −12(x − 5)^2 + 10.