精选优质文档-倾情为你奉上摘 要二次曲线是高中数学的重点和难点，而二次曲线的弦又是其主要内容之一，很多问题都有直接或间接涉及到。本文先分别给出二次曲线的焦点弦、中点弦和切点弦的定义，研究它们的若干性质；然后再分别探讨这三类二次曲线的弦在解题中的应用。关键词：二次曲线；焦点弦；中点弦；切点弦Abstract Quadratic curve is the emphasis and difficulty in high school mathematics, and conic string is one of the main content, a lot of problems have directly or indirectly involved. Respectively, the paper proposes the focus of the conic strings, midpoint chord and tangent point of definition, study their some properties; Then disc
