均值定理是求函数最值的重要方法 ,但需具备“正、定、等”条件 ,当这些条件不完全具备时不能直接使用 ,常需对函数式作“添、裂、配、凑”变形使其完全满足条件后方可用之 ,对变形能力的要求较高 .然而有些题由于解析式自然 ,形态根本凑不出定值 ,或虽凑出定值而等号又不能成 Mean value theorem is an important method to find the maximum value of a function, but it must have “positive, definite, and equal” conditions. When these conditions are not completely available, they cannot be directly used, and it is often necessary to make a “Tim, Split, Match, Minute” deformation of a functional formula. After it is fully satisfied with the conditions available, the requirement for deformability is higher. However, some questions due to the analytical nature, the form simply cannot be fixed, or even if the equal sign can not be equalized