摘要
极限保号性是极限理论中的重要性质,对这一性质的教与学,本文提出比现行教材更全面,更简捷明确,更便于学习者掌握其实质的阐述方法。
Polar invariance of signs is an essential nature in the theory of polarity. This article states more perfect,more direct and definitude, and more convenient method of expa-tiating the nature.
关键词
极限
保号性
极值
教学
学习
polarity
invariance of signs
extremum
