(1)把沿翻折,点O的对称点为点Q.
①如图1,当点Q刚好落在弧上,求弧的长;
②如图2,点Q落在扇形内部,的延长线与弧交于点C,过点Q作,垂足为H,,求的长;
(2)如图3,记扇形在直线上方的部分为图形W,把图形W沿着翻折,点B的对称点为点E,弧所在的圆与的延长线交于点F,若,求的长.
同类型试题
y = sin x, x∈R, y∈[–1,1],周期为2π,函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x, x∈[–1,1], y∈[–π/2,π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2
y = sin x, x∈R, y∈[–1,1],周期为2π,函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x, x∈[–1,1], y∈[–π/2,π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2