Consider the function f(ac) = 203 - 4.5x2 - 12x + 1. a) Determine the intervals on which f is concave up and concave down. f is concave up on: f is concave down on: b) Based on your answer to part (a), determine the inflection points of f. Each point should be entered as an ordered pair (that is, in the form (x, y)). (Separate multiple answers by commas.)