Answer:

Step-by-step explanation:
Let us consider this as sine function,
Equation of this function can be represented as
           f(t) = a + b sin (ωt) ---------------eqn 1
Where a, and b are constants, we need to find values of a and b.
Let us consider at time time, t = 0 low tide occurs,
         f (0) = 4.1 feet
 Substituting in eqn 1
               f(0) = a + b sin (ωx0)
                 4.1 = a + b x 0 
                  a = 4.1
               f(t) = 4.1 + bsin(ωt)  ---------------eqn 2
The maximum sine function is 1, so for high tide sinωt = 1
Substituting in eqn 2
               17.2 = 4.1 + b x 1
                  b = 17.2 -4.1 = 13.1 feet
              f(t) = 4.1 + 13.1 sinωt --------------------eqn 3
The maximum of sine occurs at 7.6 hours, sinωt value is 1 at t = 7.6 hours
                               1 =sin(ω x 7.6)
                            
