Domain is the set of possible values for x. It consists of EVERY NUMBER that X can represent. Range is the set of possible values for y. It consists of EVERY NUMBER that Y can represent. REMEMBER D comes before R and X comes before Y

When a line segment has a closed circle, that number is included in your domain and range. When a line segment has an open circle, that number is not included in your domain and range. This closed circle tells me that my domain exists at -6 and my range exists at -3. This open circle tells me that my domain gets infinitely close to 7 but does not exist at 7 and my range gets infinitely close to 2 but does not exist at 2.

 Closed circles are represented by brackets [ ] or by the inequalities ≤ and ≥.  Open circles are represented by parenthesis ( ) or by the inequalities.  DOMAIN [-6,7) or -6 ≤ x < 7  RANGE [-3,2) or -3 ≤ x < 2

x = -7, 2, 6, 7 -6 ≤ x ‹ 7 [-6,7)

-4 ≤ y ‹ ∞ [-4, ∞) y = -4, 0,3