Answer
As shown on the graph,
(a) The function is increasing on $(1,\infty)$,
(b) The function is decreasing on $( -\infty) ,1)$.
Work Step by Step
Moving from left to right, the function $f$ is decreasing for x-values up to $x=1$
and increasing for all x-values larger than 1.
So,
(a) The function is increasing on $(1,\infty)$,
(b) The function is decreasing on $( -\infty) ,1)$.
