与平面曲线方向相关的几个注记

Some Remarks on the Direction of Plane Curves

从理论分析与几何直观的角度,或辅以实例,说明如何确定平面曲线切向量的方向、积分曲线的方向以及曲线切向量与内、外法向量的关系.

This paper studies theoretically and illustrates intuitively how to determine the directions of tangent vectors of plane curves and the relationship between these tangent vectors and the inside and outside normal vectors of the curves.