怎样选取参数，建立轨迹的参数方程４２２８２６湖南邵东十二中王向群在解析几何中，求动点的轨迹方程是教材的重点、难点，亦是高考命题的热点．特别是在建立动点轨迹的参数方程时，对于怎样去找参数，一部分学生往往难以把握，感到困难．其实在解几中，虽然通常使用的参... How to select parameters, establish the trajectory of the parameter equation 422826 Hunan Shaodong twelve in Wang Xiangqun In analytical geometry, the trajectory equation of the solution point is the focus and difficulty of the teaching material, and is also a hot spot of the college entrance examination proposition. Especially when establishing the parametric equation of the dynamic point trajectory, some students find it difficult to grasp and feel difficult to find the parameters. In fact, in the solution of several, although the commonly used parameters...