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坐标系内一点关于坐标轴的对称点的坐标具有某种规律.如果两点关于γ轴对称,其横坐标互为相反数;如果关于x轴对称,其纵坐标互为相反数.已知两点关于平行于坐标轴的直线对称.其坐标也有变化规律.轴对称与三角形全等联系密切.可以利用轴对称变换前后是全等形,确定点的坐标的变化规律.下面结合例题对用坐标表示轴对称的问题分类解析,供参考.一、确定一点关于坐标轴以及平行于坐标轴的直线的对称点的坐标例1如图1所示,已知点A的坐标是(-5,0),点B的坐标是(-2,0),点C的坐标是(-1,-3).连接OC.(1)判断△OBC是否是等腰三角形,并说明理由.(2)过y轴上点D(0,-3/2),引x轴的平行线PQ.点A关于PO的对称点E与点C的连线与x轴有什
The coordinates of a point with respect to the axis of symmetry in the coordinate system have a certain regularity. If two points are symmetrical with respect to the γ axis, their abscissas are mutually opposite, and if they are symmetrical with respect to the x axis, their ordinates are mutually opposite. Point on the line parallel to the axis of symmetry. The coordinates also have changes in law. Axisymmetry and triangle congruence closely. You can use the axisymmetric transform is equal form, to determine the coordinates of the point of change. Axisymmetric problem classification analysis, for reference.One, to determine a bit About the coordinate axis and the coordinates of the line parallel to the axis of symmetry Example 1 As shown in Figure 1, the known point A coordinates (-5,0 ), The coordinate of point B is (-2,0) and the coordinate of point C is (-1, -3). Connect OC. (1) Judge whether or not the OBC is isosceles triangle, and explain the reason. Point D (0, -3/2) on the y-axis, parallel to the x-axis PQ. Point A is about the point of symmetry of PO