解析几何中,我们常会遇到一类与中点有关的问题,一般的处理方法是设直线方程,代人圆锥曲线方程,转化为一元二次方程,利用韦达定理来解,思路自然,但有时运算量太大.但如果采用“设点代入,作差求解”的方法来解,常常可减少运算量.避免错误. In analytical geometry, we often encounter a class of problems related to the midpoint. The general processing method is to set the linear equation, the conic equation of the generation, to a quadratic equation, and to use the Vedic theorem to solve the problem. The idea is natural, but Sometimes the amount of computation is too large. However, if you use the method of “spot substitution, solving for difference”, you can often reduce the amount of computation and avoid mistakes.