chapter  9
6 Pages

Matrix Groups

WithVictor E. Hill, Thomas T. Read

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 ] .