Mathematics Specification A - 4MA1 PearsonEdexcel

Inequalities

Overview

Inequalities describe relationships where one quantity is greater than, less than, or not equal to another. Unlike equations, which pin down a single value, an inequality defines a whole range of values that satisfy a condition. From budgeting constraints to engineering tolerances, inequalities model any situation where limits apply rather than exact targets.

This lesson covers the four inequality symbols, how to represent solution sets on a number line using open and closed circles, and how to solve linear inequalities. You will also learn to shade regions on a Cartesian graph defined by linear inequalities. Higher tier extends into quadratic inequalities and harder region problems.

Objectives

  1. Understand and use the inequality symbols
  2. Understand and use the convention for open and closed intervals on a number line
  3. Solve simple linear inequalities in one variable and represent the solution set on a number line
  4. Represent simple linear inequalities on rectangular Cartesian graphs
  5. Identify regions on rectangular Cartesian graphs defined by simple linear inequalities
  6. [Higher] Solve quadratic inequalities in one unknown and represent the solution set on a number line
  7. [Higher] Identify harder examples of regions defined by linear inequalities

Lesson Note

A theme park sign reads 'You must be at least 140 cm tall to ride'. Translated into algebra this becomes \(h \geq 140\), an inequality. Unlike an equation, which has one answer, this statement is true for every height from 140 cm upwards. Inequalities crop up whenever a rule sets a boundary rather than an exact value.

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Lesson Evaluation

Congratulations on completing the lesson on Inequalities. Now that youve explored the key concepts and ideas, its time to put your knowledge to the test. This section offers a variety of practice questions designed to reinforce your understanding and help you gauge your grasp of the material.

You will encounter a mix of question types, including multiple-choice questions, short answer questions, and essay questions. Each question is thoughtfully crafted to assess different aspects of your knowledge and critical thinking skills.

Use this evaluation section as an opportunity to reinforce your understanding of the topic and to identify any areas where you may need additional study. Don't be discouraged by any challenges you encounter; instead, view them as opportunities for growth and improvement.

  1. Solve 3x + 2 > 14. A) x > 4 B) x > 6 C) x > 3 D) x < 4 Answer: A
  2. Which number line correctly shows x <= 3? A) Open circle at 3, arrow right B) Filled circle at 3, arrow left C) Open circle at 3, arrow left D) Filled circle at 3, arrow right Answer: B
  3. Solve -2x > 6. A) x > -3 B) x < -3 C) x > 3 D) x < 3 Answer: B
  4. Which integers satisfy -1 < x <= 3? A) -1, 0, 1, 2, 3 B) 0, 1, 2, 3 C) 0, 1, 2 D) -1, 0, 1, 2 Answer: B
  5. On a graph, the region below the line y = 2x + 1 (not including the line) is described by: A) y >= 2x + 1 B) y <= 2x + 1 C) y > 2x + 1 D) y < 2x + 1 Answer: D

Available on the Green Bridge App

Download the Green Bridge CBT app on your phone or computer to access full lesson notes, practice questions, and more.

Full lesson notes with diagrams
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Available on Android, Windows, macOS, and Linux

Available on the Green Bridge App

Download the Green Bridge CBT app on your phone or computer to access full lesson notes, practice questions, and more.

Full lesson notes with diagrams
AI-powered learning assistant
Study offline, anytime, anywhere
Available on Android, Windows, macOS, and Linux

Practice Mock Questions

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