(Solved): The figure shows the depth of water at the end of a boat dock. The depth is 8 feet at low tide ...

The figure shows the depth of water at the end of a boat dock. The depth is 8 feet at low tide and 16 feet at high tide. On a certain day, low tide occurs at $$6\mathrm{AM}$$ and high tide at noon. If $$y$$ represents the depth of the water $$x$$ hours after midnight, use a cosine function of the form $$y=A\cos Bx+D$$ to model the water's depth.