In: Math
7. The depth of water in a bay changes due to the tide. On one particular day, the depth can be modeled by ? = 6 cos (2π/11) + 7, where ? is hours since midnight, and ? is depth in metres.
a) Calculate the depth of the water at midnight.
b) At what rate is the depth changing at 4:00 a.m.?
c) At what time, between midnight and noon is the water level rising fastest?