Modeling Periodic Phenomena with Trigonometric Functions Practice Test

In a certain city, the number of daylight hours varies sinusoidally over the year. The city has about 8 hours of daylight at its minimum (in December) and about 16 hours at its maximum (in June). The pattern repeats every 12 months. What are the amplitude and midline of a sinusoidal model for daylight hours?

A buoy moves up and down with the waves. Its vertical displacement from the calm-water level ranges from $-2$ m (lowest) to $+2$ m (highest). One complete up-and-down cycle takes 8 seconds. What are the amplitude, midline, and period for a sinusoidal model of the buoy’s displacement?