The M¨obius strip and a tentative to construct a normal unit vector field on it To each P in S the Gauss map assigns a point N(P) on the unit sphere S 2 . http://uregina.ca/recservices

To each P in S the Gauss map assigns a point N(P) on the unit sphere S 2 .

We haven’t defined differentiability of maps from S to R 3 . Like in Section 3.2, N : S → R 3 is differentiable means that for any local parametrization (U, ϕ) of S, the map N ◦ϕ : U → R 3 is differentiable. Equivalently, any of the three components of N is a differentiable function from S to R.

http://uregina.ca/recservices


http://uregina.ca/recservices

高等代数学 - 第 367 頁 - Google 圖書結果

https://books.google.com.hk/books?isbn=7302082278 - 轉為繁體網頁

张贤科, ‎许甫华 - 2004

... 张量) :外积(向量)空间川 V 可等同于 QV 中交错张量全体 AT 厂( V ) ,但二者的乘法不可简单等同。 ... 为了与原来可交换的乘积相区别,这后一种"乘积"记为 dx八dy ...