Water spraying from a large fountain follows a path modeled by the function h(d) = -2/3d^2+ 4d, for h > 0, where h is the height of the water above the fountain jet and d is the horizontal distance of the water from the fountain jet, both in metres.

a) Graph the function (do not need to hand in) and use the graph to determine the maximum height of the fountain. (2 marks)
b) What horizontal distance does the water travel from the fountain jet before it reaches the maximum height? (2 marks)