摘要
讨论在微分几何课程中关于张量的计算及应注意的问题．特别指出了在Ｅｉｎｓｔｅｉｎ和式公约中易犯的错误并揭示了ｇｉｋｇｋｌ＝δｌｋ与矩阵乘法的关系．证明了定理“曲面上一点处，两主曲率相等，则该点处一切方向均为主方向”。
The paper discusses Tensor’s computation and some problems of needing attention in the teaching of differential geometry course, and points out that a easily making mistake to Einstein’s summation convention and reveals the relation ship between g ik g kl =δ l k and matrix multiplication. Finally, a theorem:“At a point on a surface, if two principal curvatures equality, then all directions are principal direction” is proved and some examples are given.
出处
《四川师范大学学报（自然科学版）》
CAS
CSCD
1999年第1期93-97,共5页
Journal of Sichuan Normal University（Natural Science）
