A barn is 100 feet long and 40 feet wide (see figure). A cross section of the roof is the inverted catenary given below. y = 31 - 10(ex/20 + e-x/20) Find the number of square feet of roofing on the barn. (Round your answer to the nearest whole number.) ft -20 20- 100 ft 20 y=31-10(ex/20 + e-x/20)