For a sinusoidal model with maximum \(M\), minimum \(m\) and period \(T\):
\(\text{Amplitude}=\dfrac{M-m}{2}\qquad c=\dfrac{M+m}{2}\qquad b=\dfrac{2\pi}{T}\)
Use \(b=360^\circ/T\) for degrees. Choose sine or cosine and the sign to match the starting value and direction.
Tide model: \(h=3\sin\dfrac{\pi t}{6}+5\), \(0\le t\le24\)
| Feature | Value |
|---|---|
| Mean depth | 5 m |
| Amplitude | 3 m |
| Period | 12 hours |
| High tide | 8 m at \(t=3,15\) |
| Low tide | 2 m at \(t=9,21\) |
Substitute a time to find the value, or solve the trigonometric equation to find every time in the given interval. State units.
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