摘要
熟知欧氏参数曲面在非脐点处有且仅有两个相互垂直的主方向.对相互垂直的理解是容易的,但文献[3]的处理方法在实际教学中,学生理解主方向只有两个时存在模糊之处.本文目的是仔细分析这些模糊之处及产生的原因,并给出较为清晰的补充修缮,以更好地为教学服务.
It is known that there are exactly two perpendicular principal directions at a non umbilical point on a parameterized surface. It is easy to understand that the two principal directions are perpendicular. However, omissions and ambiguities still exist in[3] concerning to explain why there are exactly two principal directions. This paper tries to analyze the reasons and clean omissions and ambiguities, aiming to serve the teaching well.
出处
《河西学院学报》
2014年第5期18-21,共4页
Journal of Hexi University
基金
国家自然科学基金项目(11261051)资助课题
关键词
参数曲面
主方向
正交
共轭
Parametric surface
Principal direction
Conjugate
