The price, P, of stock in pounds during a 9-hour trading window can be modelled by P = 17.4 + 2 sin (0.7t − 3), where t is the time in hours after the stock market opens, and angles are measured in radians.

a. State the beginning and end price of the stock.

b. Calculate the maximum price of the stock and the time when it occurs.

c. A day trader wants to sell the stock when it firsts shows a profit of £0.40 above the day’s starting price. At what time should the trader sell the stock?