An auditorium with a flat floor has a large screen on one wall. The lower edge of the screen is 4 ft above eye level and the upper edge of the screen is 12 ft above eye level (see figure). How far from the screen should you stand to maximize your viewing angle? 12 ft 4 ft X . . . What is the objective function, 0, in terms of the distance from the screen, x? 0 = (Type an expression.)