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笔者有幸参与了2014年南通市中考数学试卷的命题及阅卷工作,现就其中第28题(压轴题)的命制过程以及阅卷后的反思与各位同行做个交流,以供大家在教学中参考.题目如图1,抛物线y=-x2+2x+3与x轴交于A,B两点,与y轴相交于点C,顶点为D,抛物线的对称轴DF与BC相交于点E,与x轴相交于点F.(1)求线段DE的长;(2)设过点E的直线与抛物线相交于点
I was fortunate enough to take part in the 2014 Nantong City entrance exam papers proposition and marking the work, is now on the 28th (Finale) the process of life and the reflection after the reading and colleagues to make a communication for your reference in teaching . The subject is shown in Figure 1. The parabola y = -x2 + 2x + 3 is intersected with the x axis at points A and B, intersects the y axis at point C, and the vertex is D. The symmetry axis of parabola DF intersects BC at point E, Intersects the x-axis at point F. (1) Find the length of the line segment DE; (2) Let the straight line passing through point E intersect the parabola at point