不等式恒成立问题是高中数学的一个重点与难点,也是高考的一个热点问题,它渗透着换元、化归、数形结合、函数与方程等数学思想方法。只有让学生懂得不等式恒成立问题的本源是什么,才能使学生真正体会问题的本质,从而提高思维的有效性。 Inequality constant problem is established in high school mathematics, a key and difficult point, but also a hot topic in college entrance examination, which permeated with exchange yuan, return to the number of forms, functions and equations and other mathematical methods. Only by letting the students know what the origin of the inequality is, is it possible for the students to really understand the essence of the problem so as to improve the effectiveness of thinking.