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GCSE Graphs Revision Guide

Master linear, quadratic, and cubic graphs with our comprehensive guide designed for AQA, Edexcel, and OCR specifications.

Foundation

Higher Tier

Exam Practice

Formulae

Topic Overview

Coordinate geometry is a fundamental pillar of GCSE Mathematics. This guide covers the relationship between algebraic equations and their visual representations on a Cartesian plane. You will explore how to plot points, calculate gradients, and understand how transformations—such as reflections, translations, and stretches—affect the parent functions of linear and non-linear graphs.

Whether you are preparing for the Foundation or Higher tier, mastering these concepts is essential for success in higher-level algebra and calculus.

Quick Navigation

Formulae

Lessons

Examples

Resources

Essential Formulae

y = mx + c

m = gradient, c = y-intercept

Straight Line Equation

Gradient Formula

m = Δy / Δx

Change in y divided by change in x

Lesson Modules

Equation of a Line

Mastering y=mx+c for all exam boards.

Distance-Time

Analysing speed from gradients.

Reflections

Mirror lines and coordinates.

Translations

Vector shifts on the plane.

Parallel Lines

Same gradient, different c.

Real-Life Graphs

Conversion and rate graphs.

Plotting

Tables of values & accuracy.

Stretches

Vertical and horizontal scale.

Gradient & Intercept

Finding m and c values.

Worked Example

Step-by-Step Walkthrough

THE QUESTION

Find the equation of the line that passes through (2, 5) and (4, 9).

Method

  1. Find gradient (m): (9 – 5) / (4 – 2) = 4 / 2 = 2.
  2. Substitute m and point (2, 5) into y = mx + c.
  3. 5 = (2 * 2) + c => 5 = 4 + c.
  4. Solve for c: c = 1.

Common Mistake

Using (x1 - x2) / (y1 - y2) instead of (y2 - y1) / (x2 - x1). Always remember: "Rise over Run".

Final Answer

y = 2x + 1

Revision Resources

Worksheet

Worksheet (PDF)

Interactive Quiz

Timed interactive y=mx+c quiz.

Exam Questions

Past paper questions by difficulty.

Mark Scheme

Step-by-step solutions for all Qs.

Playlist

3 Videos

Expert Video Tutorials

Frequently Asked Questions

What is the gradient?

The gradient represents the steepness of a line. In the equation y = mx + c, it is represented by the letter ‘m’. It is calculated by finding the change in y divided by the change in x between two points.

The y-intercept is the point where the line crosses the y-axis (where x = 0). In y = mx + c, it is the constant value ‘c’.

Yes, complex transformations of the form y = f(x) + a or y = f(x + a) are predominantly found on the Higher tier paper.