Any idea ?

7. A sheet of corrugated roofing is constructed by pressing a flat sheet of aluminum into one whose cross section has the form of a sine wave. If the cross-section has a period of L in., and the thickness of the corrugated sheet is 24 in., the cross-section can be described by f(:) = A - sin (xx). Suppose the manufacturer would like to produce corrugated panels that are 64 in. wide and 2 in. thick, with a period of 16 in. Set up the integral used to calculate the width of the original flat metal sheet that would be needed to make this 64-in. corrugated panel