The Angle between the normal vector of a Sphere (or other geometric object) at a point where aPlane is tangent to it and the normal vector of the plane. In the above figure,
数学辞典收录了8975条数学词条,基本涵盖了常用数学知识及数学英语单词词组的翻译及用法,是数学学习的有利工具。