When describing where a function is increasing, decreasing, or constant it is usually expressed in Blank 1 Question 1 notation.

When describing where a function is increasing, decreasing, or constant, it is usually expressed in interval notation.

Interval notation provides a concise way to represent the set of x-values over which the function exhibits a particular behavior. For example, if a function is increasing on the interval from $a$ to $b$, it can be expressed as $(a, b)$ in interval notation. If the function is decreasing from $c$ to $d$, it would be written as $(c, d)$. The notation uses parentheses for open intervals (excluding the endpoints) and brackets for closed intervals (including the endpoints).