关于曲面的主方向个数的简易判定  

The easy judgement on the number of hyperboloid's principle direction

作　　者：汤小松 

机构地区：井冈山师范学院数学与应用数学系，江西吉安343009

出　　处：《井冈山师范学院学报》2003年第6期29-31,共3页

摘　　要：在古典微分几何中,对于曲面的主方向个数的判定,学生易产生误解.为了使学生不产生误解,本文就曲面的主方向个数的判定提出一个简易方法即运用一元二次方程的根与系数的关系这一代数理论来对曲面的主方向个数进行判定.In the Classic Differential Geometry,students may easily clause wrong comprehension on the judgement of the number of hyperboloid's principle direction.In order to avoid the wrong com-prehension,this paper brings forward a easy solution to the judgement of the number of hyperboloid's principle direction.In which the number of hyperboloid's principle direction is judged by using the relations of root and coefficient of eqations with1variabe and2degrees.

关 键 词：曲面 主方向个数 一元二次方程 根 系数 古典微分几何 

分 类 号：O186.11[理学—数学]