函数在中学数学学习中占有重要的地位,研究函数其实重点就是研究函数的性质,而在函数的诸多性质中,函数单调性是函数的重要性质之一,在历年高考中对函数单调性的考查都有涉及;灵活运用函数单调性解题,能起到事半功倍、化繁为简的效果。首先我们来回顾一下函数单调性的定义:一般地,设函数f(x)的定义域为I,如果对于定义域I内某个区间D上的任意两个自变 Function plays an important role in the middle school mathematics learning. In fact, the research function focuses on the nature of the function. In many properties of the function, the monotonicity of the function is one of the important properties of the function. In the past years, the monotonicity of the function Have involved; flexible use of monotonic solution to problems, can play a multiplier, the effect of simplification. First of all, let’s review the definition of monotonicity: Generally, let f (x) be the domain of I, and for any two automorphisms in a certain interval D in domain I