“利用重要不等式求最值”教学中应过的三关湖北省云梦县一中秦小乔１．基本运用关掌握用重要不等式求函数最值的基本方法，重视运用过程中的三个条件：正数、相等、常数．可通过以下几例提醒学生注意．例１求函数ｙ＝ｘ＋４ｘ的值域．错解：∵ｘ＋４ｘ≥２ｘ·４ｘ（当ｘ... Three Kinds of “Using the Important Inequality to Find the Best Value” in the Teaching of the Three Passes in Yunmeng County, Hubei Province The basic use of the key to grasp the basic method of using the important inequality to find the value of the function, pay attention to the three conditions in the process: positive, equal, constant. You can use the following examples to remind students to pay attention. Example 1 finds the value range of the function y=x+4x. The wrong solution: ∵x+4x≥2x·4x (when x...