(1)求a的值;
(2)如图①,点P是抛物线C上任意一点,过点P作直线l的垂线,垂足为Q.求证:PO=PQ;
(3)请你参考(2)中的结论解决下列问题:
①如图②,过原点作直线交抛物线C于A,B两点,过此两点作直线l的垂线,垂足分别为M,N,连接ON,OM,求证:OM⊥ON;
②如图③,点D(1,1),探究在抛物线C上是否存在点F,使得FD+FO取得最小值?若存在,求出点F的坐标,若不存在,请说明理由.
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