非有限闭区间上连续函数最值的存在性

Most have Limited Value in the Continuous Function on a Closed Interval Existence

在现实生活及各个领域中经常涉及到非有限闭区间上连续函数的最值问题,因此有必要讨论非有限闭区间上连续函数最值的存在性.以区间[a,b)、[a,+∞)、(a,b)和(-∞,+∞)为例给出并证明了半开区间、开区间和无穷区间上连续函数存在最大值、最小值的条件.

The actual life together with various fields, often involves close -range continuous function on the most limited value, it is necessary to discuss the existence of continuous function maximum and minimum on a closed interval value. Interval [a,b）、[a,＋∞）、（a,b）and （-∞,＋∞） is taken for example to prove the maximum and minimum conditions of the continuous function on a half - open interval, open interval and infinite interval.