论文部分内容阅读
圆既是轴对称图形,又是中心对称图形,还具有旋转不变性。圆的这些特性决定了圆的某些问题会出现双解,有些同学由于审题不严,思考不周往往会造成漏解.现将圆中常见的双解问题归纳如下,供同学们参考.一、与点和圆的位置有关的多解问题例1已知点到⊙O上的点的最大距离是6cm,最小距离是2cm,则圆的半径r=cm.分析:由题意可知:点P不在圆上,应分点P在圆内和圆
Circle is both axisymmetric graphics, but also the center of the symmetrical graphics, but also has the rotation invariance. These characteristics of the circle determine some of the problems of the circle there will be double solution, some students due to lax trial, thinking is often not easy to cause leakage. Now common in the circle of double solution problems are summarized below, for students to reference. , And the location of the point and the circle of multi-solution problem Example 1 known point to ⊙ O point maximum distance is 6cm, the minimum distance is 2cm, the radius of the circle r = cm Analysis: From the title we can see: point P is not on the circle, should point P within the circle and circle