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.