Operating window for two control variables (u 1 and u 2 ). The dashed lines are objective function contours, increasing from left to right. The maximum profit occurs where the profit line intersects the constraints at vertex D (1).

Operating window for two control variables (u 1 and u 2 ). The dashed lines are objective function contours, increasing from left to right. The maximum profit occurs where the profit line intersects the constraints at vertex D (1).