Amodel for the length of daylight (in hours) in philadelphia on the tth day of the year is l(t) = 12 + 2.8 sin 2π 365 (t − 80) . use this model to compare how the number of hours of daylight is increasing in philadelphia on march 21 and april 21. (assume there are 365 days in a year. round your answers to four decimal places.)