MA16-09 Maths Coming soon

Stretching and Reflecting a Graph: y=af(x), y=f(ax)

MA16-09

This lesson is coming soon.

Watch now instead: MA23-01 Perimeter of 2D and composite shapes

In this lesson

Sketch y=af(x) and y=f(ax) for a given function's graph, including the reflection case where a=-1.

What it covers

Sketching y=af(x) as a vertical stretch (or squash, for 0<a<1) of a given graph
Sketching y=f(ax) as a horizontal stretch/squash of a given graph
The reflection case: y=-f(x) reflects in the x-axis, y=f(-x) reflects in the y-axis

Key words

stretch reflection af(x)f(ax)

For: AQA GCSE 8300, Edexcel GCSE 1MA1, Eduqas GCSE C300, OCR GCSE J560, Edexcel IGCSE 4MA1

On the specification

Board	Spec	Statement
AQA GCSE 8300	A13	Sketch translations and reflections of a given function
Edexcel GCSE 1MA1	A13	Sketch translations and reflections of a given function
Eduqas GCSE C300	HA13	Sketch translations and reflections of a given function
OCR GCSE J560	7.03a	Identify and sketch translations and reflections of a given graph (or the graph of a given equation).
Edexcel IGCSE 4MA1	H3.3B	Apply to the graph of y = f(x) the transformations y = f(x) + a, y = f(ax), y = f(x + a), y = af(x) for linear, quadratic, sine and cosine functions
Edexcel IGCSE 4MA1	H3.3C	Interpret and analyse transformations of functions and write the functions algebraically

For teachers

This GCSE Maths lesson teaches stretching and Reflecting a Graph: y=af(x), y=f(ax). By the end, students should be able to sketch y=af(x) and y=f(ax) for a given function's graph, including the reflection case where a=-1. It works through two worked examples and the mistakes examiners report.