A company finds that if it charges x dollars for a cell phone, it can expect to sell 1,000−2x phones. The company uses the function r defined by r(x)=x⋅(1,000−2x) to model the expected revenue, in dollars, from selling cell phones at x dollars each. a. Use graphing technology to graph the function r . Sketch the graph here and show the coordinates of the vertex and any intercepts.