Answer: The function is decreasing on the intervals (-∞,-2]U(-1,∞)
Explanation:
You can see on the graph that the first part of the function is downward sloping from negative infinity until it's local minimum at (-2,1), and then goes up until the point (-1,2), where it drops to a new line segment that starts with a hole. I used parentheses for negative and positive infinity, as they are not defined numbers and thus cannot be exact. I also used parentheses for -1 has the part at -1 where it is decreasing is a hole, and is thus not actually decreasing at -1 but everywhere after -1.