A lighthouse with a rotating beam is located 500m south of a coastal cliff that runs west to east

a) determine a relation for the distance from the lighthouse to the point the light strikes the cliff in terms of the angle of rotation x

b) determine an exact expression for this distance x = 5pi/12

1 answer

draw a diagram. Clearly
cos(x) = 500/d, so
d = 500/cos(x)
Now just plug in whatever x value you have.