二次曲线有关切线的问题是一个老问题,也是一个繁杂的问题,但都是从切点坐标或切线的斜率这两个角度来导出切线方程,解决有关切线的问题。如果我们从切线方程的系数与原方程的系数关系这一点出发,同样能推导出简单易记的结论,在解决实际问题中也切实可行,对某些问题的解答比起前两种办法更加方便,简捷。本文拟就这方面谈点体会。 The problem of the tangent of the quadratic curve is an old problem, it is also a complicated problem, but the tangent equations are derived from the two angles of the tangent point coordinates or the tangent slopes, and the problems related to the tangent lines are solved. If we start with the relationship between the coefficients of the tangent equations and the coefficients of the original equations, we can also derive simple and memorable conclusions. We are also practical and feasible in solving practical problems. It is more convenient to solve certain problems than the former two methods. Simple. This article intends to talk about this experience.