2.3 Region Representing Inequalities in Two Variables


2.3.1 Position of a point relative to the graph of y = ax + b
1. When y = ax + b, the point is on the line.
2. When y < ax + b, the point is below the line.
3. When y > ax + b, the point is above the line. 


2.3.2 Identifying the region satisfying the respective inequalities.
1.      A dashed line ‘----’ is used when points on the line are not included in the region representing the inequality, such as y > ax + b or y < a or x > a.
2.      A solid line ‘___’ is used when points on the line are not included in the region representing the inequality, such as yax + b or y ≤  a or xa.
3.      The diagrams below show the regions that satisfy the respective inequalities.