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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 This closed circle tells me that my domain exists at -6 and my range exists at -3. 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 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 < and >. DOMAIN [-6,7) or -6 ≤ x < 7 RANGE [-3,2) or -3 ≤ x < 2 x = -7, 2, 6, 7 -6 ≤ x ‹ 7 [-6,7) y = -4, 0,3 -4 ≤ y ‹ ∞ [-4, ∞) • • •