The sketch of the graph showing the depth of the water at midnight when t = 0 can be seen in the image attached below.
Graphical representation of a function.
A graph can be use to represent a function to make some logical deduction. Here, we can represent the word problem into a piecewise function. To sketch a graph illustrating the depth of the water relies on the time since it range between the low tide and the high tide.
Let denote some of the following parameters;
- time of the high tide (h) = 5:00 am
- time of low tide (l) = 11:30 am
- At high tide, depth of water (H) 15.0 ft
- At low tide, depth of water (L) = 9.0 ft
Representing the parameters in piecewise function, we can have a function D(t) i.e. the function of the depth in terms of time;

Replacing the values;

Thus, the sketch of the graph showing the depth of the water at midnight when t = 0 can be seen in the image attached below.