Question

An image of a parabolic lens is projected onto a graph.The y-intercept of the graph is (0, 90), and the zeros are 5 and 9. Which equation models the function? y = 90(x – 5)(x – 9) y = 2(x – 5)(x – 9) y = 90(x + 5)(x + 9) y = 2(x + 5)(x + 9)

Answer 1

y = 2 (x-5) (x-9)

Explanation:

Edge

Answer 2

Explanation:

If the zeros are 5 and 9, then the equation will have the form:

y = a (x–5) (x–9)

We know the point (0, 90) is on the curve, so we can use this to find the coefficient a:

90 = a (0–5) (0–9)

90 = 45a

a = 2

y = 2 (x – 5) (x – 9)