The daily average temperature in Santiago, Chile, varies over time in a periodic way that can be modeled approximately by a trigonometric function.
Assume the length of the year (which is the period of change) is exactly 365 days long. The hottest day of the year, on average, is January 7, when the average temperature is about 29∘C. The average temperature at the coolest day of the year is about 14∘.
Find the formula of the trigonometric function that models the daily average temperature T in Santiago t days into the year. (t=1 on January 1) Define the function using radians.