Dotted line - GCSE Maths Definition

In GCSE Maths, a "dotted line" is often used in graphs or diagrams to show a boundary or limit that is not included in the solution. For example, when you draw a graph to show a range of values that satisfies an inequality, a dotted line indicates that the values on this line are not part of the solution. This is different from a solid line, which means the values on the line are included. So, if you're shading a region on a graph to show where an inequality is true, and the line is dotted, it shows that the edge is just a guide and not included in the actual solution set.