5. One day at the beach, Sully brought his yellow rubber ducky to play in the ocean. He noticed that it bobbed up and down as the waves went past, and immediately thought, “This is a sinusoid situation...boom!" The ducky moves 4.2 feet from its low point to its high point, and then returns to its low point after a total of 8 seconds. a) Write an equation that gives the ducky's vertical position y at time t if the ducky is at its lowest point when t = 0.​