■サマーヴィルの等面四面体(その759)

F4:x2は[1]×1,y2は[1]×2倍

 (x2,y2)=(−1/3,√(1−1/3^2))に2個の頂点,

 (x1,y1)=(1,0),(x2,−y2)=(−1/3,−√(1−1/3^2))にそれぞれ頂点が1個ずつ

 [x2+s]=[r11,r12,r13,r14,r15][v6]

 [ −y2] [r21,r22,r23,r24,r25]

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F5:x2は[1]×−1/3,y2は[1]×3倍

 (x2,y2)=(−1/3,√(1−1/3^2))に3個の頂点,

 (x1,y1)=(1,0),(x2,−y2)=(−1/3,−√(1−1/3^2))にそれぞれ頂点が1個ずつ

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F6:x2は[1]×−1,y2は[1]×4倍

 (x2,y2)=(−1/3,√(1−1/3^2))に4個の頂点,

 (x1,y1)=(1,0),(x2,−y2)=(−1/3,−√(1−1/3^2))にそれぞれ頂点が1個ずつ

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F7:x2は[1]×−7/5,y2は[1]×5倍

 (x2,y2)=(−1/3,√(1−1/3^2))に5個の頂点,

 (x1,y1)=(1,0),(x2,−y2)=(−1/3,−√(1−1/3^2))にそれぞれ頂点が1個ずつ

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