Example 1: In one area of the Bay of Fundy, the tides cause the water level to rise to 6 m above average sea level and drop to 6 m below average sea level.
One cycle is completed every 12 h. Assume that changes in the depth of the
water over time can be modeled by a sine function.

a) If the water is at average sea level at midnight and the tide is coming in,
draw a graph to show how the depth of the water changes over the next
24 h. Assume that at low tide, the depth of the water is 2m.
b) Write the equation of the graph.
c) If the water is at average sea level at 02:00, and the tide is coming in,
write an equation that shows how the depth changes over the next 24 h.