We identify the behaviour of the function by looking at the slope m of the curve:
• m > 0 → increasing,
,
• m = 0 → constant,
,
• m < 0 → decreasing.
Looking at the graph, we see that:
From the graph, we see that:
• increasing: (-∞, -7), (-2, -1),
,
• constant: (-5, -2), (-1, +∞),
,
• decreasing: (-7, -5).
Answer
The intervals are:
• increasing: (-∞, -7), (-2, -1),
,
• constant: (-5, -2), (-1, +∞),
,
• decreasing: (-7, -5).
