《微分几何》教材的几点商榷

摘要

for the textbook , Differential Geometry , compiled by Mei Xiangming , Huang Jingzhi , the paper puts forward three different opinions about some knowledge in it .Firstly, surface of the equation is a net first order nonlinear differential equation .Sec-ondly, in developable surface r→ =a→( u) +v b→( u), parameters|v|is wires p( u,v) Point to the office of a bus straight distance . b→(u) can also just across the conductor on the straight a→(u) on the bus direction vector.Thirdly, when the fixed point P on the de-velopable surface along a straight moving bus , its normal vector is always collinear and cutting plane is unchanged .%对梅向明、黄敬之编写的《微分几何》教材中的3个知识点提出不同意见：曲面网的方程是一个一阶非线性微分方程；直纹面方程 r→＝a→（u ）＋vb→（u）中，参数｜v｜为导线上a→（u）点到直母线上任一点P（u，v）的距离，b→（u）也可以只是过导线上a→（u）点的直母线上的方向向量；可展曲面上动点P沿一条直母线移动时，它的法向量始终共线，切平面不变。