2/3 3/3 300 1,300/10 COS 20 [Got it, thanks!] 300 1 t 60 + 2 dt = 3 sin (7) - 3 sin(6) t COS 20 60 t - [2 in (+2) = 3 60 = 3 sin(7) - 3 sin(6) In conclusion, between t = 240 and t = 300 the number of daylight hours increases by 3 sin (7) - 3 sin(6) hours. + 2 dt 300 240