现将06年宁波市中考第26题的分析、探索、反思、感悟摘文如下,供大家参考．题如图1,已知(?)O过点D(4,3),点H与点D关于y轴对称,过H作(?)O的切线交y轴于点A．(1)求(?)O的半径; (2)求sinHAO的值; (3)如图2,设(?)O与y轴正半轴交点P,点E、F是线段OP上的动点(与点P不重合),连姑并延长DE、DF交 The analysis, exploration, reflection, and comprehension of the 26th issue of the 2006 Ningbo Entrance Examination are now listed for your reference. The problem is shown in Fig. 1. It is known that (?)O crosses point D(4,3), point H and point D are symmetric about the y-axis, and H crosses the tangent line of (?)O to the y-axis at point A. (1) Find the radius of (?) O; (2) Find the value of sinHAO; (3) As shown in Fig. 2, set the intersection point of (?) O with the positive half shaft of y-axis, point E, F is the movement on the line segment OP Point (do not overlap with point P), even if you extend DE and DF