■DE群多面体の面数公式(その885)
421の基本単体の頂点は,ρについて
P0(0,0,0,0,0,0,0,0)
P1(1,0,0,0,0,0,0,0)
P2(1,1/√3,0,0,0,0,0,0)
P3(1,1/√3,1/√6,0,0,0,0,0)
P4(1,1/√3,1/√6,1/√10,0,0,0,0)
P5(1,1/√3,1/√6,1/√10,1/√15,0,0,0)
P6(1,1/√3,1/√6,1/√10,1/√15,1/√21,0,0)
P7(1,1/√3,1/√6,1/√10,1/√15,1/√21,1/√28,0)
P7(1,1/√3,1/√6,1/√10,1/√15,1/√21,1/√28,√(9/4))
cosθ=28/{21+28}^1/2{28+4/9}^1/2=4/(16/3)=3/4***
cosθ=√(4/9)/{28+4/9}^1/2=√(4/9)√(9/256)=√(1/64)=1/8
σについて
P0(0,0,0,0,0,0,0,0)
P1(1,0,0,0,0,0,0,0)
P2(1,1/√3,0,0,0,0,0,0)
P3(1,1/√3,1/√6,0,0,0,0,0)
P4(1,1/√3,1/√6,1/√10,0,0,0,0)
P5(1,1/√3,1/√6,1/√10,1/√15,0,0,0)
P6(1,1/√3,1/√6,1/√10,1/√15,1/√21,0,0)
P7(1,1/√3,1/√6,1/√10,1/√15,1/√21,√(2/7),0)訂正した
P8(1,1/√3,1/√6,1/√10,1/√15,1/√21,√(2/7),√2)
cosθ=21/{15+21}^1/2{21+7/2}^1/2=1/2√2***
cosθ=7/2/{21+7/2}^1/2{7/2+1/2}^1/2=7/2・√2/7・1/2=1/2√2***これで整合した.
cosθ=1/√2/{7/2+1/2}^1/2=1/2√2***
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