Based on the theory of differential geometry and geodesy, the second order differential equation and the first differential relationship are derived on the regional earth ellipsoid in this paper.
通过在积分换元、微分方程求解、多（一）元复合函数求全微分、偏导数及高阶偏导数中的应用举例，论述了一阶微分的形式不变性在微积分学中的作用不应被忽略。
The Earth is not round: Ellipsoid models.
地球不是圆的：椭圆体模型。
Earth is an ellipsoid and its surface is curved, but the maps are usually drawn to the floor plan on paper. So before drawing you must spread the curved surface surface to the plane first.
地球椭球体表面是曲面，而地图通常要绘制在平面图纸上，因此制图时首先要把曲面展为平面。
Earth is an ellipsoid and its surface is curved, but the maps are usually drawn to the floor plan on paper. So before drawing you must spread the curved surface surface to the plane first.
地球椭球体表面是曲面，而地图通常要绘制在平面图纸上，因此制图时首先要把曲面展为平面。
应用推荐