Question

The image of a parabolic lens is projected onto a graph. The image crosses the x-axis at –2 and 3. The point (–1, 2) is also on the parabola. Which equation can be used to model the image of the lens?

y = -1/5 (x – 2)(x + 3)
y = -1/3(x – 2)(x + 3)
y = -1/2 (x + 2)(x – 3)
y = 1/4 (x + 2)(x – 3)

Answer 1

c

Explanation:

Answer 2

The factors of the equation will be (x-(-2)) = (x +2) and (x -3). Only the last two choices have these factors.

The point (-1, 2) is above the x-axis and between the zeros, so the parabola opens downward. Only the third choice does that.
y = -1/2(x +2)(x -3)