4 2 -6 -4 X -2 2 4 6 -2 -4 -6 (i) Identify the critical numbers of f. (Enter your answers as a comma-separated list.) X : -2,1,4 X (ii) Identify the open interval(s) on which f is increasing or decreasing. (Enter your answer using interval notation.) increasing (-2,1), (1,4) X decreasing (-00, - 2), (4,00) X (iii) Determine whether f has a relative maximum, a relative minimum, or neither at each critical number. (Enter your answers as a comma-separated list.) relative minimum X = - 2 X relative maximum X = 4 X