Answer:
Step-by-step explanation:
the x-intercepts represent that the profit is $0
maximum value represents the highest profit which is $270
increasing intervals: (0, 4)
decreasing intervals: (4, 8)
in order to find the average rate of change, find the x and y coordinates for when x = 1 and x =4. The coordinates are (1, 120) and (4, 270). The average rate of change is basically the slope, which is (270-120)/(4-1) = 160/3= approximately 53.3333. The rate represents the change in profit in $ over the increase of cost of erasers.
As you can see, this a parabola, which consists of going up and down. The constraints of the domain represent that 4 is the best price for eraser because it yields the highest profit. The domain (x values) that are above and below 4 do not yield the best profit.
