Lighthouse Function p.553 #69

69. A Lighthouse Beacon

The beacon of a lighthouse 400 meters from a straight sea wall rotates at 6 revolutions per minute. Using the accompanying figures, write an equation expressing , measured in meters, in terms of time . Assume that when , the beam is perpendicular to the sea wall. Sketch a graph of the equation for  seconds. In the diagram below, adjust the slider for and see if you can find a relationship between  and . Then look for a way to express  in terms of  first and then in terms of  . Check the box to animate the lighthouse.