Hi there! When talking about interval notation, we use regular parentheses e.g. (). Interval notation is a way to describe continuous sets of real numbers by the numbers that bound them. When written, they look somewhat like ordered pairs. Although, they are not meant to denote a specific point. They are meant to be a shorthand way to write an inequality or system of inequalities.
With interval notation, we use use square brackets e.g. [ ].
With inequalities, we use "less than or equal to" ≤ or "greater than or equal to": ≥ to include the endpoint of the interval. Inclusive inequalities with the “or equal to” component are indicated with a closed dot on the number line and with a square bracket using interval notation. Strict inequalities without the “or equal to” component are indicated with an open dot on the number line and a parenthesis using interval notation
