Consider the equation below. (if an answer does not exist, enter dne.) f(x) = x3 − 3x2 − 9x + 7 (a) find the interval on which f is increasing. (enter your answer using interval notation.) find the interval on which f is decreasing. (enter your answer using interval notation.) (b) find the local minimum and maximum values of f. local minimum value local maximum value (c) find the inflection point. (x, y) = find the interval on which f is concave up. (enter your answer using interval notation.) find the interval on which f is concave down. (enter your answer using interval notation.) click grade this after you answer a question, and then click show answer. after answering all question parts, you can click show solution or try again.