Answer:
(-∞, -1) and (2, ∞)
Explanation:
A function is increasing when the slope is positive (y gets bigger as x gets bigger)
A function is decreasing when the slope is negative (y gets smaller as x gets bigger)
At the turning points (stationary points) the slope is zero.
Therefore, from inspection of the graph:
- increasing → (-∞, -1)
- decreasing → (-1, 2)
- increasing → (2, ∞)