In Exercises sketch the appropriate curves. A calculator may be used.

At 40°N latitude the number of hours h of daylight each day during the year is approximately h = 12.2 + 2.8 sin [π/6 (x − 2.7)],  where x is measured in months (x = 0.5 is Jan. 15, etc.). Sketch the graph of h vs. x for one year. (Some of the cities near 40°N are Philadelphia, Madrid, Naples, Ankara, and Beijing.)