determine all intervals on which the graph of $f$ is decreasing.\ngraph of $f$

Explanation:

Step1: Identify decreasing interval 1

A function decreases when as $x$ increases, $y$ decreases. From the peak at $x=-5$ to the lowest point at $x=2$, the graph falls. Interval: $(-5, 2)$

Step2: Identify decreasing interval 2

Check left segment: from $x=-\infty$ to $x=-5$, the graph rises, so it is increasing. From $x=2$ to $x=+\infty$, the graph rises, so it is increasing. The only other decreasing segment is not present; confirm the first interval and check the middle drop from $x=-5$ to $x=2$, and also check the segment from $x=-5$ to $x=2$ is the only decreasing part? Wait, recheck: from $x=-5$ (the local maximum) moving right to $x=2$ (the local minimum), the $y$-values go from 3 down to -5, so that's decreasing. Also, check the part from $x=-3$ to $x=2$? No, the peak is at $x=-5$, so starting at $x=-5$, moving right, the function decreases until $x=2$.

Answer:

The function is decreasing on the interval $(-5, 2)$