Consider the equation below. x 2 f (x ) = - x2+ 4 (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. (If an answer does not exist, enter DNE.) local minimum value local maximum value (c) Find the inflection points. smaller x-value ( x, y ) = larger x-value ( x, y ) = Find the interval on which fis concave up. (Enter your answer using interval notation.) Find the interval on which f is concave down. (Enter your answer using interval notation.)