■葉序らせん(その82)
b=.443818の計算について再考.
A(0,0,b)
B(0,0,−b)
C(0,h,0)
D(x,y,0)
E(−x,y,0)
F(α,β,γ)
G(ξ,η,ζ)
h^2+b^2=1
AC^2=h^2+b^2=1
AD^2=x^2+y^2+b^2=1
CD^2=x^2+(y−h)^2=1
x^2+y^2=h^2
b^2=−2hy+h^2
y=(h^2−b^2)/2h=(2h^2−1)/2h
y^2=(2h^2−1)^2/4h^2
x^2=h^2−y^2
−b^2=x^2+y^2−1
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y軸の回りに回転させると
A(−bs,0,bc)
B(bs,0,bc)
C(0,h,0)
D(xc,y,xs)
E(−xc,y,−xs)
F(αc−γs,β,αs+γc)
G(ξc−ζs,η,ξs+ζc)
O(0,Y,0)
AO^2=BO^2=Y^2+b^2s^2
CO^2=(Y−h)^2
DO^2=EO^2=(Y−y)^2+x^2c^2
では,xy平面への投影を考えている.
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