Which of the situations below (if any) is best modeled by a sinusoidal function? Explain your reasoning.

1. The number of students in each year's graduating class.

   Hint (a):

   The population of your school's graduating class may increase and decrease over time.
   What kind of graph would best show this information?

   Answer (a):

   This would be modeled best with a step graph.

2. Your hunger level throughout the day.

   Hint (b):

   Are you hungry and not hungry at the same times each day?

   Answer (b):

   This may or may not be periodic.

3. The high-tide level at a point along the coast.

   Answer (c):

   The high and low tide graph is approximately periodic over short periods of time.
   Do a Google search for 'tide graph images' to see for yourself.