(a) (i) The function y = 12 I has a tangent line drawn at the point (-1, 2). Find the equation of this tangent line. (2) (ii) For what values of x is the function decreasing? Justify your answer. (2) (b) The height of water (in metres) at the entrance to a bay { hours after high tide (at 8am) is: H - 10 + 2 cos 6 (i) Find the rate of change of height at 11.30am. (2) (i) Is the tide rising or falling at 11.30am. Explain. (1)