A city averages 14 hours of daylight in June, 10 in December,
and 12 in both March and September. Assume that the number of hours
of daylight varies sinusoidally over a period of one year. Write a
function for n, the number of hours of daylight, as both a sine and
a cosine function of t. Let t be in months and t = 0 correspond to
the month of January. What is the average amount of daylight hours
in August?