■葉序らせん(その26)

 ここで座標変換を行いたい.

  A(−s/2,−√3/5,c/2)

  C(0,3√3/10,0)

  D(c√(2/3),−√3/30,s√(2/3))

  E(−c√(2/3),−√3/30,s√(2/3))

  F(αc−γs,β−y,αs+γc)

  G(ξc−ζs,η−y,ξs+ζc)

  O(0,0,0)

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cos(∠DOE)=(−2c2/3+1/300+2s^2/3)/{2/3+1/300)

s^2=3/5,c^2=2/5を代入すると

cos(∠DOE)=(−80/300+1/300+120/30)/(2/3+1/300)=41/201

cos(∠AOC)=−9/50/{3/25+1/4)^1/2(27/100)^1/2

=−9/50/(37/100)^1/2(27/100)^1/2

=−18/√37√27

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