学习数学的核心是解题,而解题时应选择怎样的策略是一个解题者十分关注的问题,本文仅就用极端思想解常见的函数选择题作些盘点,以期对大家的学习有所启发和帮助.1线性函数例1对于a∈[-1,1],若函数f(x)=x2+(a-4)x+4-2a的值总大于0,则实数x的取值范围是().A.(1,3)B.(-∞,1)∪(3,+∞) Learning mathematics is the core of the problem-solving, and problem-solving should choose what kind of strategy is a problem-solicitor is very concerned about the issue, this paper only use extreme ideas to solve the common function of multiple choice for some inventory, with a view to everyone’s learning Inspiration and help.1 Linear function Example 1 For a∈ [-1,1], if the value of the function f (x) = x2 + (a-4) x + 4-2a is always greater than 0, the range of the real number x Is () .A. (1,3) B. (- ∞, 1) ∪ (3, + ∞)