与参数方程有关问题的四种解法

• 作 者: 刘彩琴
• 机 构: 甘肃省定西市渭源县第一中学,
• 出 处: 中学生数学
• 发表日期: 2017年03期
• 关键词: 参数方程 普通方程 弦长公式 距离公式 几何意义 一元二次方程 单位圆 解方程组 韦达 对应点

参数方程是以参变量为中介来表示曲线上点的坐标的方程,是曲线在坐标系下的另一种表示形式.某些曲线用参数方程比普通方程更简便,但笔者认为要将它应用自如必须深刻理解其实质,如:参数的几何意义、普通方程与参数方程的相互转化、及熟悉参数方程代表的是哪种曲线等,这些才是解题的关键.

The parametric equation is an equation that takes the parameter as an intermediary to represent the coordinates of the point on the curve, which is another representation of the curve under the coordinate system. Some of the curves are easier to use than the normal equation in parameter equations, but I think it should be applied It is imperative to have a deep understanding of its essence, such as the geometric meaning of the parameters, the mutual transformation of the ordinary equations and the parametric equations, and the familiar curves of the parametric equations. These are the key points for solving the problem.