H [2 pts.] Determine the interval on which / (1) = 2 2 4 3 is increasing. (A) (-3/2, V3/2) (B) (0,00) (C) (-DO, -V3/2) (D) (V3/2, 00) (E) None of these (2 pts.] Determine the interval on which the graph of f(2) - e-or is concave down. (A) (-0.2, 0.2) (B) (0,00) (C) (-00, 0) (D) (-V5, V5) (E) None of these (2 pts.] Find the critical number(s) of f(x) = r(4 - 2) 1/3. (A) a = 4 only (B) r = 3 only (D) : = 0 and z = 3 only (C) r =4 and r = 3 only (E) None of these