一、问题的源起数学课上,老师带领我们探讨了点到直线的距离的求法.首先我们一起回顾了两直线li:Ax+By+Ci=0(i=1,2)的位置关系(重合、相交、平行),发现条件“A1/A2=B1/B2≠C1/C2”仅仅解决了两平行直线方向相同的问题,要确定两平行线的位置关系,还必须研究它们的距离.接着老师引导我们选择常规思路:思路一取点——作垂线——求垂足坐标——代两点间的距离 First, the origin of the problem in the math class, the teacher led us to explore the method of the distance from the point to the straight line. First of all, we reviewed the positional relationship between two lines li: Ax+By+Ci=0 (i=1, 2) ( Coincident, intersecting, parallel), found that the condition “A1/A2=B1/B2≠C1/C2” only solved the problem of the same direction of the two parallel lines. To determine the positional relationship between the two parallel lines, we must also study their distance. The teacher guides us to choose the routine thinking: the idea of ​​taking a point - making a vertical line - seeking the coordinates of the foot - on behalf of the distance between two points