Introduce the approach of C. F. Gauss to differential geometry, which relies on a parametric description of a surface, and the Gauss - Rodrigues map from an oriented surface S to the unit sphere S^2, which describes how a unit normal moves along the surface.

The first fundamental form describes the Euclidean quadratic form in terms of the parametrization, and the second fundamental form is determined by the derivative of the Gauss - Rodrigues map.

ที่มา : http://www.youtube.com/channel/UCXl0Zbk8_rvjyLwAR-Xh9pQ

ลิงค์ : http://youtu.be/drOldszOT7I

อัพโหลดโดย : njwildberger