Consider the function f(:L') : 8:1: l g. (a) Find all critical numbers c of f. c : (b) f is concave up for a: E (c) f is concave down for :1: E (01) Using the 2nd derivative test, the local maxima of f occur at :1: : (e) Using the 2nd derivative test, the local minima of f occur at a", : Note: Input U, infinity, and -infinity for union, 00, and 00, respectively. If there are multiple answers, separate them by commas. If there is no answer, input none