The intervals on which f(x) ≥ 0 on the graph are (-∝, 3) and (5, 8)
How to determine all intervals on which f(x) ≥ 0
from the question, we have the following parameters that can be used in our computation:
The graph
From the graph, we have the following
Increasing interval = (-4, 1) and (4, 6)
This is because the y values increase as x increase
Decreasing interval = (-∝, -4), (1, 4) and (6, ∝)
This is because the y values decrease as x increase
Intervals on which f(x) ≥ 0 = (-∝, 3) and (5, 8)
This is because the y values at these intervals are non negatives