综观历年高考解析几何试题,有六大热点.一、曲线轨迹方程的问题探求曲线的轨迹方程,即求曲线上动点坐标所满足的代数条件是解析几何的最基本问题,它在历年高考中频繁出现.全国高考85、86、91、93、94、95年均以这类问题为压轴题.此类问题通常是通过建立坐标系,设动点坐标,依据题设条件,列出等式,代入化简整理即得曲线的轨迹方程.基本方法有:直译法、定义法、代入法、交轨法、几何法、参数法、极坐标法等.例1 已知椭圆 x~2/24+y~2/16=1,直线l:x/12+y/8=1.P是 l 上一点,射线 OP 交椭圆于点 R,又点 Q 在 OP 上且满足|OQ|·|OP|=|OR|~2,当点 P 在 l 上移动时,求点 Q 的轨迹方程,并说明轨迹是什么曲线.(1995年 Looking at the analytical geometry exam questions in the college entrance examination over the years, there are six hot spots. First, the problem of the curve trajectory equation Search for the trajectory equation of the curve, that is to find the algebraic condition satisfied by the moving point coordinate of the curve is the most basic problem of analytical geometry. Frequent appearances in the national college entrance examination in 85, 86, 91, 93, 94, and 95 years have adopted this type of problem as the finale title. Such problems are usually established by setting up a coordinate system, setting the coordinates of the moving point, and setting the conditions according to the title. , Substitute into the simplified trajectory equation to get the curve. The basic methods are: literal translation method, definition method, substitution method, intersection method, geometry method, parameter method, polar coordinate method, etc. Example 1 Known Ellipse x~2/24 +y~2/16=1, the straight line l:x/12+y/8=1.P is the upper point of l. The ray OP intersects the ellipse at point R, and the point Q is at OP and satisfies |OQ|·|OP |=|OR|~2, when point P moves on l, find the trajectory equation of point Q and explain what the trajectory is. (1995