求解无条件极值的常用方法

The Commonly Used Method of Solving the Unconditional Extreme Value

求无条件极值问题难度比较大,技巧性比较强、解法灵活多样,所以对无条件极值的求法的探讨是相当有必要且十分重要的.本文总结了无条件极值的一些常用方法:利用二阶偏导数求函数极值,由函数的正定性解决三元以上函数的极值问题,应用二次函数求极值,利用不等式法求极值,且对每种方法都给出了例子,用来说明解题技巧.

The unconditional extremum problem is more difficulty,and the methods of solving the unconditional extremum problem are skillful,flexible and varied.Therefore the discussion on solving unconditional extreme value is quite necessary and important.This paper summarizes some commonly used methods of solving unconditional extreme value：using the second order partial derivative function extreme value,solve the extremum problems of three variables functions or multivariate function based the positive definiteness of functions,etc.,and examples are given for each method is used to indicate the skills.