■葉序らせん(その43)

 (その36)を訂正.

 s^2=24/25,c^2=1/25,y=8√3/25

  A(−s/2,−8√3/25,c/2)

  B(s/2,−8√3/25,c/2)

  C(0,9√3/50,0)

  D(c√(2/3),−23√3/150,s√(2/3))

  E(−c√(2/3),−23√3/150,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(∠AOC)=(−216/1250)/(s^2/4+192/625)^1/2・9√3/50=(−216/1250)/(600/2500+768/2500)^1/2・9√3/10・・・無理数

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[まとめ] s^2=3/5,c^2=2/5,y=√3/5でよい.

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