A company finds that if it Charges x dollars for a cell phone, it can expect to cell 1,000-2x phones. The company uses the function r defined by r(x) = x (1000 - 2x) to model the expected revenue, in dollars, from selling cell phones at xdollars each. Use graphing technology to graph the function r. What do the x intercept means in this situation? Is 0 < x < 600 an appropriate domain for the function r? At what price should the company sell their phones to get the maximum revenue? Explain your reasoning.​