Edexcel IGCSE Maths 复习笔记 2.17.2 Inequalities on Graphs - Interpreting

How do we interpret inequalities on a graph?

• First, see Inequalities and Straight Line Graphs

Once you do… 

1. Write down the EQUATION of each line on the graph
2. REMEMBER that lines are drawn with: 

   A solid line for ≤ or ≥ (to indicate line included in region)A dotted line for < or > (to indicate line not included)

3. REPLACE = sign with:≤ or < if shading below line ≥ or

   > if shading above line(Use a point to test if not sure)