求点P(x0,y0)关于直线l:Ax+By+C=0(AB≠0)的对称点Q(x,y)的一般方法是解方程组y-y0x-x0.(-AB)=-1A(x+x0)2+B(y+y0)2+C=0(1)(2)(*)但对学生来说,此方程组列出容易,解起来比较复杂,特别当A、B数值不太凑巧时,出错率较高.笔者在教学过程中,惊喜地发现求点关于直线的对称点坐标可以 The general method of finding the point P(x0,y0) about the symmetry point Q(x,y) of the straight line l:Ax+By+C=0(AB≠0) is to solve the system of equations y-y0x-x0.(-AB) =-1A(x+x0)2+B(y+y0)2+C=0(1)(2)(*) But for students, the equations are easy to list and more complex to solve, especially when A, B, when the value is not too good coincidence, the error rate is higher. In the teaching process, the author was surprised to find that the coordinates of the point of symmetry about the straight line can be