Question

A graph shows price (dollar sign) labeled 4 to 16 on the horizontal axis and profit (dollar sign) on the vertical axis. A line of orange dots increases from 0 to 6 starting at 80 on the vertical axis, then decreases from 6 to 16.
Which function represents profit, P(x), as a function of x, the price per music class?

P(x) = –(x – 6)2 + 116
P(x) = (x + 6)2 + 116
P(x) = –2(80x)
P(x) = –80(2x)

Answer 1

P(x) = –(x – 6)^2 + 116

Reason: the graph is a downward-opening parabola with vertex at x = 6 and P(6) = 116, and P(0) = -(0-6)^2 + 116 = 80 matches the given point.