数量关系是数学研究的核心内容之一,而数量关系既包括等量关系,也包括不等量关系．与刻画等量关系的等式、方程、函数等模型相对应,不等式则是刻画普遍存在的不等关系的典型模型．理解进而掌握不等式模型,不仅可以深化对等式、方程等模型的理解,而且可以丰富自己的数学认知结构,为后续学习奠定重要基础．为此,我们必须深刻理解以下三个问题． The quantitative relationship is one of the core contents of mathematics research, and the quantitative relationship includes both equal and unequal relations. Correspond to the equations that describe the relationship between equations, equations, and functions, inequalities are typical models that portray ubiquitous inequalities. Understanding and mastering the inequality model not only can deepen the understanding of equations, equations and other models, but also can enrich their mathematical cognitive structure, laying an important foundation for follow-up study. To this end, we must profoundly understand the following three issues.