问题情境:
数学活动课上,老师出示了一个问题:如图1,在中,D,E分别是边的中点,相交于点G.
独立思考:
(1)试猜想与的数量关系,并加以证明.
实践探究:
(2)如图2,在正方形中,,以为斜边作等腰直角,使,连接交于点N,求的值.
问题解决:
(3)如图3,在菱形中,,点P在边上,点Q在的延长线上,连接,,射线交于点M.若,请直接写出的长.
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