11/01/27 00:43:39
>>198
cosθ'- cosθ = P/a,
sinθ'- sinθ = Pc/b,
・２乗して辺々たすと
2 - 2cos(θ'-θ) = (P/a)^2 + (Pc/b)^2,
θ' - θ = arccos{1 - (1/2)(P/a)^2 -(1/2)(Pc/b)^2},
・また、辺々割って和積公式を使えば
-tan((θ'+θ)/2) = b/ac,
θ' + θ = -2arctan(b/ac),
11/01/27 00:43:39
>>198
cosθ'- cosθ = P/a,
sinθ'- sinθ = Pc/b,
・２乗して辺々たすと
2 - 2cos(θ'-θ) = (P/a)^2 + (Pc/b)^2,
θ' - θ = arccos{1 - (1/2)(P/a)^2 -(1/2)(Pc/b)^2},
・また、辺々割って和積公式を使えば
-tan((θ'+θ)/2) = b/ac,
θ' + θ = -2arctan(b/ac),