4. A function f is continuous on [-4, 4] and twice differen- tiable on (-4, 4). Some information on f, f', and f" is tab- ulated below: X (-4, -2) -2 (-2, 0) 0 (0, 2) 2 (2, 4) f' (x ) positive 0 negative negative negative 0 negative f" (x ) negative negative negative 0 positive 0 negative (a) Give the x-coordinates of the local maxima and minima of f. (b) Give the x-coordinates of the points of inflection of the graph of f. (c) Given that f(0) = 0, sketch a possible graph for f