Edexcel IGCSE Maths (4MA1) · Unit 4: Graphs & Functions
IGCSE Maths Inequalities on Graphs Questions and Answers
Inequalities on Graphs questions with full solutions for Pearson Edexcel International GCSE Mathematics A (4MA1), Higher tier. Read the 2 worked examples first, then try the 3 exam-style questions yourself and check your working against the mark scheme.
Regions on Graphs 1: Linear Inequalities on a Grid: Showing and describing regions defined by linear inequalities on a grid.
Regions on Graphs 2: Harder Inequalities: Shading regions defined by several inequalities.
Inequalities on Graphs worked examples
Worked example 1: Linear inequalities on a grid
The region R is given by \(x\ge0\), \(y\ge1\) and \(2x+y\le6\). Find its vertices and decide whether \((2,\ 2)\) is in R.
Solution
Vertices: \((0,\ 1)\), \((0,\ 6)\), and \(2x+1=6\) gives \((2.5,\ 1)\).
Test \((2,\ 2)\): \(2\times2+2=6\le6\) ✓, \(x\ge0\) ✓, \(y\ge1\) ✓.
So \((2,\ 2)\) is in R (on the boundary, which is included).
Answer: Vertices \((0,1),\ (0,6),\ (2.5,1)\); yes
Tip: Solid lines for ≤ and ≥, dashed for < and >.
Worked example 2: Vertices of a region
Find the vertices of the region \(y\le3\), \(y\ge x-1\), \(x+y\ge1\).
Solution
\(y=3\) and \(y=x-1\): \((4,\ 3)\).
\(y=3\) and \(x+y=1\): \((-2,\ 3)\).
\(y=x-1\) and \(x+y=1\): \(2x=2\), \((1,\ 0)\).
Answer: \((4,3),\ (-2,3),\ (1,0)\)
Tip: Each vertex is where two boundary lines meet.
Inequalities on Graphs exam-style questions
Try each question before you open the answer. The mark schemes use Edexcel-style marks: M for method, A for accuracy (after the method mark), B for an independent result.
Question 1 · easy · 1 mark
A region on a coordinate grid lies to the left of the line \(x=3\), including points on the line. Write down the inequality that describes the region.
Show the answer and mark scheme
B1 x ≤ 3
Answer: \(x\le 3\)
Question 2 · medium · 3 marks
Find the coordinates of the vertices of the region defined by \(y\ge0\), \(y\le x\) and \(x+y\le8\).
Show the answer and mark scheme
B1 (0, 0)
B1 (8, 0)
B1 (4, 4)
Answer: \((0,0),\ (8,0),\ (4,4)\)
Question 3 · hard · 3 marks
The region R is defined by \(y\ge1\), \(y\le2x\) and \(x+y\lt 7\). Find the number of points with integer coordinates in R.
Show the answer and mark scheme
M1 correct points for at least two values of x, e.g. x = 1: (1,1), (1,2)
M1 systematic count for x = 1 to 5
A1 12
Answer: 12
Every question and worked example here is original, written for IGCSE Math Revision rather than copied from Pearson papers, and each answer was re-solved independently before publishing.
Which Edexcel IGCSE Maths papers test inequalities on graphs?
Either Higher tier paper, 1H or 2H, can test inequalities on graphs: both cover the whole Pearson Edexcel International GCSE Mathematics A (4MA1) specification and both allow a calculator. Show your method, because most marks are for working.
Where can I practise more inequalities on graphs questions?
In the IGCSE student hub: Unit 4 (Graphs & Functions) has more exam-style questions on this topic, each with a mark scheme. Practice starts with a 7-day free trial; the worked examples and questions on this page are free.