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Unformatted text preview: The telling observation now is that vertices (as well as edges and faces) are really permuted in pairs. So we consider the action of the rotation group on pairs of opposite vertices, or, what amounts to the same thing, on the four diagonals of the cube. See Figure 4.1.8 . This gives a homomorphism of the rotation group of the cube into S 4 . Since both the rotation group and S 4 have 24 elements, to show that this is an isomorphism, it sufces to show that it is injective, that is, that no rotation leaves all four diagonals xed. This is easy to check. Proposition 4.1.4. The rotation group of the cube is isomorphic to the permutation group S 4 . The close relationship between the rotation groups of the tetrahedron and the cube suggests that there should be tetrahedra related geometrically...
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This note was uploaded on 12/15/2011 for the course MAC 1105 taught by Professor Everage during the Fall '08 term at FSU.
 Fall '08
 EVERAGE
 Algebra

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