大象传媒

Transformation of curves - Higher - OCRTranslating graphs

Functions of graphs can be transformed to show shifts and reflections. Graphic designers and 3D modellers use transformations of graphs to design objects and images.

Part of MathsAlgebra

Translating graphs

The translation of graphs is explored

A graph can be translated horizontally, vertically or in both directions.

Translations parallel to the y-axis

\(y = x^2 + a\) represents a translation parallel to the \(y\)-axis of the graph of \(y = x^2\). If \(a\) is positive, the graph translates upwards. If \(a\) is negative, the graph translates downwards.

Example 1

\(y = x^2\)

\(y = x^2 + 3\)

Graph showing translations parallel to the x-axis

Example 2

\(y = x^2\)

\(y = x^2 - 2\)

A graph showing translations parallel to the x-axis

\(y=x^2 + a\) represents a translation of the graph of \(y = x^2\) by the vector \(\begin{pmatrix} 0 \\ a \end{pmatrix}\).

This is also true for other graphs.

For example, \(y = x^3 - 2\) is a translation of \(y = x^3\)by the vector \(\begin{pmatrix} 0 \\ -2 \end{pmatrix}\) and \(y = sin x + 3\) is a translation of \(y = sin x\) by the vector \(\begin{pmatrix} 0 \\ 3 \end{pmatrix}\).

Translations parallel to the x-axis

\(y = (x + a)^2\) represents a translation parallel to the \(x\)-axis of the graph of \(y = x^2\).

If \(a\) is positive then the graph will translate to the left. If the value of \(a\) is negative, then the graph will translate to the right.

Example 1

\(y = x^2\)

\(y = (x + 3)^2\)

Graph showing  y = x^2 y = (x + 3)^2

Example 2

\(y = x^2\)

\(y = (x - 2)^2\)

Graph showing  y = x^2  y = (x 鈥 2)^2

\(y = (x + a)^2\) represents a translation of the graph of \(y = x^2\) by the vector \(\begin{pmatrix} -a \\ 0 \end{pmatrix}\)

This is also true for other graphs. For example, \(y = (x + 2)^3 \) is a translation of \(y = x^3\) by the vector \(\begin{pmatrix} -2 \\ 0 \end{pmatrix}\) and \(y = sin(x 鈥 30)\) is a translation of \(y = sin x\) by the vector \(\begin{pmatrix} 30 \\ 0 \end{pmatrix}\).