Trigonometric functions of for an integer cannot be expressed in terms of sums, products, and finite root
extractions on *real* rational numbers because 11 is not a Fermat Prime. This also means that the Undecagon is not
a Constructible Polygon.

However, exact expressions involving roots of *complex* numbers can still be derived using the trigonometric identity

(1) |

(2) |

(3) |

(4) |

(5) |

(6) | |

(7) | |

(8) |

(9) |

**References**

Beyer, W. H. ``Trigonometry.'' *CRC Standard Mathematical Tables, 28th ed.* Boca Raton, FL: CRC Press,
1987.

© 1996-9

1999-05-26