One January 1st at West Bay, the firsy low tide was at 1:30am and at 0.7m, and the first high tide was at 7:45am at 2.8m. Assuming high tides and low tides occur at regular intervals. 1. Find two equivalent trigonometric equations that model the height in m of the tide at West Bay in terms of tike (t) in hours since midnight.

(You must use two different trigonometric functions from sine, cos or tan, and set t=0 as midnight on 1st January for each question)

2. Justify and prove that the two equations are equivalent, unless the proof is shown in your working.