GraphsKey Facts

Cubic Graph Essentials

Part of Cubic Graphs · GCSE GCSE Mathematics revision

This key facts covers Cubic Graph Essentials within Cubic Graphs for GCSE Mathematics. Revise Cubic Graphs in Graphs for GCSE Mathematics with 11 exam-style questions and 10 flashcards. This topic appears less often, but it can still be a useful differentiator on mixed-topic papers. It is section 2 of 10 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.

Topic position

Section 2 of 10

Practice

11 questions

Recall

10 flashcards

Cubic Graph Essentials

General form: y = ax³ + bx² + cx + d (a ≠ 0)
a > 0: positive cubic — rises from bottom-left to top-right
a < 0: negative cubic — falls from top-left to bottom-right
Roots: can have 1, 2, or 3 x-intercepts
Turning points: 0 or 2 (never exactly 1)
y-intercept: substitute x = 0, y = d

Keep building this topic

Read this section alongside the surrounding pages in Cubic Graphs. That gives you the full topic sequence instead of a single isolated revision point.

The Roller Coaster Curve Positive vs Negative Cubic Shapes Key Features of Cubic Graphs Drawing a Cubic Graph

Practice Questions for Cubic Graphs

Which of the following best describes the general shape of the graph y = x³?

A. U-shape (parabola) opening upward
B. S-shaped curve rising from bottom-left to top-right
C. Horizontal straight line
D. S-shaped curve falling from top-left to bottom-right

1 markfoundation

Explain how you can tell from the equation of a cubic whether its graph rises or falls as x approaches positive infinity.

2 markshigher

Quick Recall Flashcards

What does the graph of y = x³ look like?

A smooth S-shaped curve. Key features: - Passes through the origin (0, 0) - Rises steeply for large positive x - Falls steeply for large negative x - Has a point of inflection at the origin (where it flattens then curves again)

How many roots can a cubic graph have?

A cubic graph can have 1, 2 or 3 roots (x-intercepts). - 3 distinct roots: crosses x-axis three times - 2 roots: touches at one point and crosses at another - 1 root: only crosses once (with a repeated root) Cubics ALWAYS have at least one real root.

11 questions on Cubic Graphs — practise free

Instant marking, adaptive difficulty, and 10 spaced repetition flashcards. Free until your GCSEs.

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The Roller Coaster Curve

Positive vs Negative Cubic Shapes