Remember that for a graphic of a trigonometric functions of the form 
is the amplitude of the function
is the midline of the trigonometric function
We know form our problem that
, so the amplitude of our function is 5. We also know that the 
. So the midline of our function is the line 
.
Using those two features we can conclude that the graph <span>that shows the height of the water at the dock at any time after midnight is: </span>
We know form our problem that
Using those two features we can conclude that the graph <span>that shows the height of the water at the dock at any time after midnight is: </span>