Use the graph to determine open intervals on which the funct
     Use the graph to determine  open intervals on which the function is increasing, if any.  open intervals on which the function is decreasing, if any  open intervals on which the function is constant, if any.   
  
  Solution
a) Increasing (-infinity, 2) and(3,4)
b) decresing (2,3) and (4, infinity)
c) never constant

