ABSTRACT
In Example 1.1 we considered a group consisting of six matrices under the operation of matrix multiplication. Since Example 1.3 was concerned with rotations of a regular hexagon in the plane, we can also express this example in terms of matrices. You should recall from linear algebra that a rotation counterclockwise about the origin through an angle θ may be expressed as a linear transformation with corresponding matrix: [ cos θ − sin θ sin θ cos θ ] . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780203719695/427c6cb8-4a8d-4df9-bf17-90e17936899a/content/eq142.tif"/>
