Question

已知⊙O的半径是2,以⊙O的弦AB为直径作⊙M

Answer 1

答：

(1)

∠C=60°

(2)

DE=√3

(3)

连接BD.

x

=AD/DC

=(BD/tan∠A)/(BD/tan∠C)

=tan∠C/tan∠A

tan∠C=√3,

tan∠A

=tan(π-∠C-∠ABC)

=tan(2π/3-∠ABC)

=(-√3-tan∠ABC)/[1+(-√3)×tan∠ABC)

=-(√3+y)/(1-√3y).

所以有

x=-√3(1-√3y)/(√3+y)

y=(√3+1)x/(3-x).(0