Question

The depth (D metres) of water in a harbour at a time (t hours) after midnight on a particular day can be modelled by the function

D = 2 sin (0.5t - 0.6) + 5, t < or = 14

where radians have been used.

Select the two options which are correct statements about the predictions based on this model.

Select one or more:

The smallest depth is 5 metres. 

The largest depth is 7 metres.

At midnight the depth is approximately 3.9 metres.

The time between the two high tides is exactly 12 hours. 

The model can be used to predict the tide for up to 14 days. 

The depth of water in the harbour falls after midnight. 

At midday the depth is approximately 7 metres. 

Answer 1

Answer 2

Can someone help me The water depth, D, in metres in a harbour on a particular day can be modelled by the equation D=3sin(30xt)+5, 0 < t < 24 Where t is the elapsed time, in Hours since midnight a) dra the graph of D versus t on the grid below