(1 point) The Nearsighted Cow Problem: A Calculus Classic. A rectangular billboard 9 feet in height stands in a field so that its bottom is 11 feet above the ground. A nearsighted cow with eye level at 4 feet above the ground stands & feet from the billboard. Express 0, the vertical angle subtended by the billboard at her eye, in terms of x. Then find the distance co the cow must stand from the billboard to maximize 0. 0(x) = is maximized when 2o = (Click on image for a larger view)