关于二次曲线弦的中点问题的简捷解法殷东生（江苏盐城师范专科学校附属中学２２４００１）在学习二次曲线时常会遇到有关弦的中点的问题，如：过已知二次曲线内一点Ｐ引一弦，使它恰在点Ｐ被平分，求该弦所在直线的方程等．解决时一般设弦所在直线的方程，代入二次曲线方... A simple solution to the problem of the midpoint of the quadratic curve string Yin Dongsheng (Jiangsu Yancheng Normal College affiliated secondary school 224001) When learning the quadratic curve, he often encounters problems with the midpoint of the string, such as: a point in the known quadratic curve. P leads a string so that it is split evenly at point P, find the equation of the line where the string lies, etc. When solving, generally set the equation of the line where the string is located, substituting the quadratic curve...