A naval ship is on a secret mission to the Middle East. Upon crossing the Atlantic Ocean it runs into some turbulent Weather: Captain Curtis is concerned about how the ship is tolerating the up and down motion of the waves, which
happen to behave in a sinusoidal manner. So, she develops a model to determine when the ship will be at the "peak
of a wave and when it will be at the valley of a wave. Att 4 seconds, the ship reaches a maximum height of 15 feet
above normal sea level, and at t = 9 seconds, the ship reaches its minimum height of 5 feet below normal sea
level Which equation BEST models this situation?