Consider the equation below. f(x) = 9 sin(x) + 9 cos(x), 0 ≤ x ≤ 2π (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.) Correct: Your answer is correct. (b) Find the local minimum and maximum values of f. local minimum value Correct: Your answer is correct. local maximum value Correct: Your answer is correct. (c) Find the inflection points. (x, y) = (smaller x-value) (x, y) = (larger x-value) Find the interval on which f is concave up. (Enter your answer using interval notation.) Correct: Your answer is correct. Find the interval on which f is concave down. (Enter your answer using interval notation.