对于证明与函数有关的不等式,或已知不等式在某范围内恒成立求参数的取值范围,讨论一些方程解的个数等类型问题时,常常需要构造辅助函数,通过求导研究其单调性或寻求其几何意义来解题.题目本身特点不同,所构造的函数可有多种形式,解题的繁简程度也因此而不同.有直接构造(如人教A版选修2-2P32B组第1题),也有稍作变形后再直接构造,有的要适当放缩后再构造,对有的数列不 For proving the inequality associated with a function, or finding the range of values ​​for a given inequality within a certain range, it is often necessary to construct auxiliary functions to discuss types of solutions such as the number of solutions and to study the monotonicity Or to seek its geometric meaning to solve problems.The subject itself has different characteristics, the function can be constructed in many forms, the complexity of the problem is therefore different.There are direct structure (such as people teach A version of the election 2-2P32B group 1 title), but also slightly deformed and then directly structure, and some should be appropriate after the contraction of the structure, for some sequences do not