解决运动中的两圆相切问题,关键在于在运动中寻找规律,在“动”中求“静”,充分利用直观图形,建立方程或函数,并利用分类讨论等数学思想进行解答.举例说明如下:一、圆在直线上运动例1(武汉)如图1,在平面直角坐标系中,点O1的坐标为(-4,0),以点O1为圆心,8为半径的圆与x轴交于A、B The key to solving the tangential problem of the two circles in the movement is to find the law in the movement, seek the “static” in the “move”, make full use of the intuitive graphics, establish the equation or function, and use the mathematics ideas such as class discussion to answer. As follows: 1. Circular movement on a straight line Example 1 (Wuhan) As shown in Fig. 1, in the plane rectangular coordinate system, the coordinate of point O1 is (-4, 0), and the point O1 is the center, and 8 is the radius of the circle and x. Axis in A, B