題組內容

6. Suppose that f(x) is continuous on [0,6] and f(0) = f(4) = 0. The graph of f'(x) is given as below, but values of f'(1), f"(2) and f'(4) are not determined. It is known that

(c)  Find intervals on which y = f(x) is concave upward. Find intervals on which y = f(x) is concave downward. Find the inflection points of f(x).