The graph below shows a company's profit ) , in dollars , depending on the price of erasers , in dollars , sold by the company Part A : What do the x - intercepts and maximum value of the graph represent ? What are the intervals where the function is increasing and decreasing , and what do they represent about the sal and profit ? ( 4 points ) Part B : What is an approximate average rate of change of the graph from 1 to 4 , and what does this rate represent ? ( 3 points ) Part C : Describe the constraints of the domain . ( 3 points )