You are a bit confused, so let's see if we can straighten you out.
It is unfortunate that the people who made mathematics gave open
intervals and points the same kind of notation. A point has an
x-value and a y-value, but an interval has two x-values.
So be EXTREMELY careful to notice the difference between the point
(a,b) and the interval (a,b), in the following:
From negative infinity to the point (-3,-2) the graph is falling, so it
is decreasing from x = negative infinity to x = -3.
So the graph is DECREASING on the interval (-oo,-3).
From the point (-3,-2) to the point (0,4) the graph is rising, so it
is increasing from x=-3 to x=0
So the graph is INCREASING on the interval (-2,0).
From the point (0,4) to the point (2,1) the graph is falling again,
so it is decreasing again from x=0 to x=2.
So the graph is DECREASING on the interval (0,2).
From the point (2,1) to positive infinity the graph is rising,
so it is increasing from x=2 to x=oo
So the graph is INCREASING on the interval (2,oo)
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Answer: increasing on the intervals (-3,0) and (2,oo).
decreasing on the intervals (-oo,-3) and (0,2).
Edwin