Help me find the intervals

Question

Use the graph of f to find the largest open interval on which f is increasing and the largest open interval on which f is decreasing. (Enter your answers using interval notation.)

(a) Find the largest open interval(s) on which f is increasing. (If two open intervals are equally large enter your answer as a comma-separated list of intervals.) 

(b) (b) Find the largest open interval(s) on which f is decreasing. (If two open intervals are equally large enter your answer as a comma-separated list of intervals.)

Answer 1

a) (0,5)

b) (5,8)