论文部分内容阅读
知识储备:1圆锥曲线的焦参数记为p,p为焦点到准线的距离;2椭圆的焦参数p=a~2/c-c=b~2/c,双曲线的焦参数p=︱(a~2/c)-c︱=b~2/c,抛物线的焦参数p=p;3圆锥曲线上的点到焦点与到相应准线的距离之比等于离心率e。(1)推理过程在圆锥曲线很多综合问题中需要求焦点弦的斜率,弦的长度等,而这类问题在近年高考中经常出现,而传统解法太过复杂,能否找到一种统一的方法来减少计算量呢?在抛物线的课后习题中课本给出了抛物线焦点弦的另一种计算方法
Knowledge reserve: 1 The focal parameter of the conic is denoted by p, p is the distance from the focal point to the quasi-line; 2 The coke parameter p = a ~ 2 / cc = b ~ 2 / c of the ellipse, a ~ 2 / c) -c | = b ~ 2 / c, the parabolic coke parameter p = p; 3 The ratio of the point on the conic curve to the focal point and the distance to the corresponding guideline is equal to the eccentricity e. (1) Reasoning process In many comprehensive conic problems need to focus on the slope of the string, chord length, etc., and these types of problems often appear in college entrance examination in recent years, while the traditional solution is too complicated, can you find a uniform method To reduce the amount of calculation? In the parabolic exercises in the textbook gives another method of calculating the parabolic focus chord