笔者最近对椭圆和双曲线焦点三角形做了些研究 ,得到了两个十分有趣的重要的轨迹 ,现说明如下 ,供读者参考 .定义　以椭圆或双曲线上一点和两焦点组成的三角形叫焦点三角形 .1　椭圆焦点三角形内心轨迹定理 1　设P是椭圆b2 x2 +a2 y2 =a2 b2 (a b 0 )上的一点 ,E( -c,0 )、F( The author recently did some research on elliptic and hyperbolic focus triangles, and got two very interesting and important trajectories, which are explained below for the reader’s reference. Definitions A triangle consisting of one or two focal points on an ellipse or hyperbola is called a focal triangle. .1 The trajectory theorem for the inner focus of an elliptical focus triangle Let P be the point on the ellipse b2 x2 +a2 y2 =a2 b2 (ab 0 ), E( -c,0 ), F(