boundary n. 边界,疆界,限界 (between);(球场)边线;界标;界限,范围,分野。 aboundary dispute 边界纠纷。 the boundary between Canada and the United States 美加国界。 boundaries on all sides 四方辐辏之所,四通八达。
By representing the essential features of section function , and presenting the theorem on discussing the limit , continuity and derivative at the boundary of section function , the article shows the reason why to choose the boundary of section function to discuss , and the method how to discuss them , while discussing the limit , continuity and derivative of section function 摘要文章通过阐述分段函数的本质特征,给出讨论分段函数在分界点处极限、连续性及导数的定理,解决在讨论分段函数的极限、连续性及导数时,为什么要在分段函数的分界点处进行讨论以及怎样讨论的问题。