(b) y (i) Identify the critical numbers off. (Enter your answers as a comma-separated list.) X= (ii) Identify the open interval(s) on which fis increasing or decreasing. (Enter your answer using interval notation.) increasing decreasing (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 = relative maximum x