1. The water depth in a harbour is 13 m at high tide and 5 m at low tide. The time between high tide and low tide is 5 hours. Based on the above information: [5 marks]
   

Adetermine an equation that describes the water depth, h metres, as a sine function of the time, t hours,

after the low tide. Use exact values . (you can assume that low tide is happening at midnight)

Bsketch the graph Show full work! You must use radians in both, the equation, and the sketch.