用平均值不等式求值域的一个变形技巧２７６４００山东省沂水教委教研室马奎文用平均值不等式求函数值域（或最值）时要遵循“一正（各项为正）、二定（积式和为定值）、三相等（存在等号成立的情况）”的原则，特别是针对“相等”要做适当的恒等变形．对于求函数ｆ（Ｘ）... A deformation technique for the evaluation of the value domain using the mean inequality 276400 Ma Kuiwen, Shandong Education Commission of the Water Quality Education Committee Using the mean inequality to find the function value domain (or the maximum value), follow the principle of “one positive (positive) and two fixed (integral) And for the fixed value), three phases, etc. (there is the case where the equal sign is established)” principle, especially for the “equal” to do the appropriate constant deformation. For the function f(X)...