We have a function of which we only know the graph.
We have to find in which intervals the function is decreasing.
We know that a function is decreasing in some interval when, for any xb > xa in the interval, we have f(xa) < f(xb).
This means that when x increases, f(x) decreases.
We can see this intervals in the graph as:
We assume each division represents one unit of x. Between divisions, we can only approximate the values.
Then, we identify all the segments in the graph where f(x) has a negative slope, meaning it is decreasing.
We have the segments: [-3, -1.5), (1,5, 4.5) and (7,9].
Answer:
The right options are:
Between 1.5 and 4.5
Between -3 and -1.5
Between 7 and 9
