A helicopter lowers a rope ladder to a scuba diver floating on the ocean surface. The waves crest at 4ft above the lowest level of the water every 8 seconds. Write a cosine equation to describe the height of the diver as a function of time t. The diver can reach 2ft abover her. The lowest rung of the ladderis 3ft above the average level of the water. For about how many consecutive seconds will the ladder be within the diver's reach