Throughout the day, the water level, [tex]\(h(t)\)[/tex], at Sunny Beach varies with the tides. Joe, a frequent visitor to Sunny Beach, arrived at the beach at 12:00 p.m. and collected the following data, where [tex]\(t\)[/tex] represents the number of hours since Joe arrived at the beach.

\begin{tabular}{|l|l|l|l|l|l|l|}
\hline
[tex]$t$[/tex] & 0 & 1 & 2 & 3 & 4 & 5 \\
\hline
[tex]$h(t)$[/tex] & 5 & 4.41 & 3 & 1.59 & 1 & 1.59 \\
\hline
\end{tabular}

Joe lost some of his data, but he knows that the highest tide occurs at 12:00 p.m., and he was able to use a trigonometric function to model the height of the tide at any time.

What is the period of the function that can be used to model the height of the tide?

A. 8 hours

B. 5 hours

C. 12 hours

D. More information is needed to solve this problem.



Answer :

To determine the period of the function that models the height of the tide at Sunny Beach, let's analyze the given data and observations:

### Data Analysis
We have height [tex]\( h(t) \)[/tex] corresponding to various times [tex]\( t \)[/tex] such as:
[tex]\[ \begin{array}{|c|c|c|c|c|c|c|} \hline t & 0 & 1 & 2 & 3 & 4 & 5 \\ \hline h(t) & 5 & 4.41 & 3 & 1.59 & 1 & 1.59 \\ \hline \end{array} \][/tex]

### Key Observations
1. Highest Tide Occurrence: According to the problem, the highest tide occurs at 12:00 p.m., which corresponds to [tex]\( t=0 \)[/tex].
2. Symmetry in Data: The data suggests symmetry about [tex]\( t = 2.5 \)[/tex] hours, where the highest and lowest points indicate a cyclical pattern:
- At [tex]\( t = 0 \)[/tex] hours, the height is [tex]\( h(0) = 5 \)[/tex] (a peak).
- At [tex]\( t = 5 \)[/tex] hours, the height returns to around [tex]\( h(5) = 1.59 \)[/tex], close to the starting value but still generally modelled as completing one cycle.

### Understanding the Period
A trigonometric function, often sin or cos, which models periodic behavior, completes one full cycle when it returns to the starting position. Given the data:
- The values show that heightened starts high at [tex]\( t = 0 \)[/tex].
- They appear to have returned to a similar (peak) structure around [tex]\( t = 5 \)[/tex], suggesting halfway through another cycle or a cyclical return.

### Conclusion
From peak to peak (from [tex]\( t=0 \)[/tex] to [tex]\( t=5 \)[/tex]), it completes one cycle. Therefore, the complete period to repeat this range is twice this interval, indicating a full cycle every 12 hours.

Thus, the period of the function that can model the height of the tide is
### 12 hours.

The correct answer is C. 12 hours.