Use the given graph of f over the interval (0, 7) to find the following. (a) The open intervals on which f is increasing. (Enter your answer using interval notation.) (b) The open intervals on which f is decreasing. (Enter your answer using interval notation.) (c) The open intervals on which f is concave upward. (Enter your answer using interval notation.) (d) The open intervals on which f is concave downward. (Enter your answer using interval notation.) (e) The coordinates of the points of inflection. (, ) (smallest x-value) (, ) (, ) (largest x-value)