A Linear Transformation of period two. Since a Linear Transformation has the form,

(1) |

(2) |

(3) |

(4) | |||

(5) | |||

(6) |

The first equation gives . Taking would require , giving , the identity transformation. Taking gives , so

(7) |

**References**

Woods, F. S. *Higher Geometry: An Introduction to Advanced Methods in Analytic Geometry.* New York: Dover, pp. 14-15, 1961.

© 1996-9

1999-05-26