An auditorium with a flat floor has a large screen on one wall. The lower edge of the screen is 3ft above eye level and the upper edge of the screen is 13ft above eye level (see figure). How far from the screen should you stand to maximize your viewing angle? What is the objective function, , in terms of the distance from the screen, x ? = (Type an expression.) The interval of interest of the objective function is (Simplify your answer. Type your answer in interval notation.) You should stand ft from the screen to maximize your viewing angle. (Type an exact answer, using radicals as needed.)