1. Note:  For this question ensure you are working in degrees.

A wave tank is used to simulate the sea at high tide. At a certain point along the tank the height of water is measured relative to the calm water level which has a height of $0cm$. The height of water in the tank is modelled by the function

$h(t)=12cos(20t)^{\circ}t\geq0$

where $h$ cm is the height of water and $t$ seconds is the time after the peak of the first wave passes the measuring point.

Sketch a graph of $h$against $t$for $0\leqt\leq54$.