■ABCからDEへ(その33)
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))
について,
cosθ=−b1^2/{b1^2}^1/2{b1^2+b2^2}^1/2
cosθ=−b2^2/{b1^2+b2^2}^1/2{b2^2+b3^2}^1/2
cosθ=−b3^2/{b2^2+b3^2}^1/2{b3^2}^1/2
などを計算する.
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cosθ=−1/{1}^1/2{1+3}^1/2=−1/2
cosθ=−3/{1+3}^1/2{3+6}^1/2=−3/6
cosθ=−6/{3+6}^1/2{6+10}^1/2=−6/12
cosθ=−10/{6+10}^1/2{10+15}^1/2=−10/20
cosθ=−15/{10+15}^1/2{15+21}^1/2=−15/30
cosθ=−21/{15+21}^1/2{21+28}^1/2=−21/42・・・ここまでは60°
cosθ=−28/{21+28}^1/2{28+4/9}^1/2=−28/7/(256/9)^1/2=−4・3/16=−3/4***
cosθ=−4/9/{28+4/9}^1/2{4/9}^1/2=−2/3/(256/9)^1/2=−2/3・3/16=−1/8
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