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题目已知抛物线y=x2上有一条长为2的动弦AB,则动弦AB中点M到x轴的最短距离为_.评完试卷后发现两个班级只有几个同学做对,可见快速准确解答出这个题目是有一定难度的,而答错的同学中填1的比较多.了解后知道,多数同学直觉上认为当动弦AB与x轴平行时,动弦中点M与x轴距离最近,而此时的距离数值就是1.应该承认同学的这种想法是有一定道理的,但很遗憾,却是错误的.为什么
Title Known parabola y = x2 has a length of 2 of the kinematic string AB, the middle point of the moving string AB M to the x-axis distance is _ .After the examination papers found that only a few classmates of the two classes do right, we can see Quick and accurate answer to the question is a certain degree of difficulty, and answer the wrong students fill more 1. Know that most students intuitively think that when the string AB parallel to the x-axis, the moving point M and x Axis distance, and the distance at this time the value is 1. It should be admitted that the students this idea is a certain truth, but unfortunately, it is wrong. Why