
The height...
The height of the water in the harbor of a coastal town is a periodic function of time.The height (in feet) is approximated by
h(t)=18+17.8sin(πt/6) , where t is time in hours since midnight.
a.when does high tide occur?what is the water height at high tide?
b.when does low tide occur ? what is the water height at low tide?
c.calculate h'(14).interpret the result in terms of time of day and water height in the harbor.

Are you allowed to use graphics calculators (where you can plot graphs) in your subject? Because this question would be made simple if you were.

Yes we can use calculators.But how would that answer this question?
Could you pls suggest something?Iam stuck..