A rain gutter is made from aluminum sheets that
28 cm wide. The first step in forming a rain gutter is to lift the edges of the aluminum sheet to form right angles, as show in in the illustration below. The cross-section
area formed by the raised edges affects the water flow. This cross-section area, A, can be represented by the function A = x(28-2x) where x
represents the height of the raised edges.
1. To the nearest centimetre, determine the height of the raised edge, x cm, which will maximize the
transverse area.