4. Find the equation of the tangent to the curve y = 52:53:) at a: = f (6 marks) 5. The movement of the crest of a wave is modelled with the function h(t) = 0.2 cos(4t) + 0.3 sin(5t). Find the maximum height of the wave and the time at which it occurs. (6 marks) 6. Determine the 19th derivative of the function y = sin($). Fully explain the process you used to determine this. (4 marks)