After spending the day building sand castles, Oceana wants to take an evening walk with
a friend along the shoreline.
Oceana knows that one stretch along the
shore is quite rocky. At that point, the rocks
jut into the ocean. To walk around them,
a person has to follow a path that is 14 feet
below the average waterline.
If Oceana and her friend don’t want to get
wet, they need to take their walk when the
waterline is 14 feet or more below the average
waterline. What is the time period during
which they can take their walk?
Remember that the position of the waterline
over the course of the day is given by the
equation w(t) 5 20 sin (29t), where the
distance is measured in feet and t represents
the number of hours elapsed since midnight.