infinitely small

This paper mainly discusses the order of infinitesimal,gets some conclusions of the comparison of infinitesimal order,and applies these conclusions to the calculation of limit and the sorting of infinitesimal.

文章对无穷小的阶进行了一些探讨,得到了几个关于无穷小阶的比较的结论,并应用于极限的计算与无穷小排序中去。

The movement of the kinematic plane on a immobile plane means that the plane infinitesimally rotate round the instantaneous velocity pole.

运动平面Σ在一个静止平面Σ0上运动,可理解为绕其瞬时转动中心作无穷小的旋转,据此可得出抛物线、椭圆和双曲线沿直线滚动时,其上任一点的轨迹曲线的法线在运动的任何时刻都通过此刻相应的切点(瞬时转动中心)的结论。