Algebra · Inequalities
Chapter 1 · 4
The idea
Inequalities as regions on a graph
Why an inequality in x and y claims a HALF-PLANE, why testing one point settles which side, and how several inequalities carve out a region together.
A full journey — read it, play with it, work it, then earn real exam marks. Everything stays on the timeline below.
In this lesson — start anywhere
Algebra · Inequalities
Inequalities as regions on a graph
Why an inequality in x and y claims a HALF-PLANE, why testing one point settles which side, and how several inequalities carve out a region together.
Why it works
A line, then a side of it
An equation like draws a LINE — the points where the two sides balance exactly. An inequality like claims everything on ONE SIDE of that line: a half-plane. The line is the boundary; the inequality picks a side. Every regions question is just these two moves — draw the boundary, choose the side — repeated once per inequality.Which side? Test a point
Take any point not on the line — the origin is usually easiest — and feed it in:Keep reading — free
The rest of the explanation, plus 2 worked examples you step through move by move.
Start freeTakes a minute — no card.