Transformation of Graphs Using Matrices - Reflection
A reflection is a transformation representing a flip of a figure. Figures may be reflected in a point, a line, or a plane. When reflecting a figure in a line or in a point, the image is congruent to the preimage.
A reflection maps every point of a figure to an image across a line of symmetry using a reflection matrix.
Use the following rule to find the reflected image across a line of symmetry using a reflection matrix.
Example:
Find the coordinates of the vertices of the image of pentagon with after a reflection across the -axis.
Write the ordered pairs as a vertex matrix.
To reflect the pentagon across the -axis, multiply the vertex matrix by the reflection matrix .
Therefore, the coordinates of the vertices of the image of pentagon are .
Notice that, both figures have the same size and shape.