|
王守恩 发表于 2020-12-12 19:45
N[Solve[{4/Sin[a] == (x + 1)/Sin[2 \/3 - a],
(x + 4)/Sin[2 a] == y/Sin[\/3] == 3/Sin[\/3 + 2 a], ...
注意2组方程的不同(s虽然用的都是正弦定理)。
1(6楼),N[Solve[{4/Sin[a] == (x + 1)/Sin[2 \[Pi]/3 - a],
(x + 4)/Sin[2 a] == y/Sin[\[Pi]/3] == 3/Sin[\[Pi]/3 + 2 a],
\[Pi]/2 > a > 0}, {x, y, a}], 40]
{{x -> 4.000000000000000000000000000000000000000,
y -> 7.000000000000000000000000000000000000000,
a -> 0.8570719478501309884131979858981848840988}}
2,Solve[{(x + 4)/Sin[\[Pi]/3 + 2 a] == y/Sin[\[Pi]/3] == 3/Sin[2 a],
4/Sin[\[Pi]/3 - a] == z/Sin[\[Pi]/3] == (x + 1)/Sin[\[Pi]/3 + a],
x > 0, \[Pi] > a > 0}, {x, y, z, a}]
{{x -> 4, y -> 7, z -> Sqrt[21], a -> -2 ArcTan[3 Sqrt[3] - 2 Sqrt[7]]}} |
|