Question

The path of a roller coaster over a particular length of track can be represented by a quadratic function f, where f(x) represents the vertical displacement above or below a support bar (in meters), and x represents the horizontal displacement to the left or right of a flagpole (in meters). The roller coaster dips below the support bar for values of x between -2 and 1. Which function could represent f?

A. f(x)=(x-2)^2+1

B. f(x)=(x+2)^2+1

C. f(x)=(x-2)(x+1)

D. f(x)= (x+2)(x-1)

Answer 1

The roller coaster could be represented by the function for Choice D.

If you were to graph this function, you would find that the zeros (x-intercepts) of the function are at the points of -2 and 1. Those are the needed points in the problem.

Since this is a parabola that opens upward, the parabola must be below the axis (or support bar) between those values.