函数是中学数学的主要内容之一,函数思想也是中学数学的主要数学思想之一,既是高三复习的重点、难点,又是高考命题的热点,是高考备考中不可或缺的课题之一。其中,函数的单调性的问题,是反映函数值随自变量的增大而增大(或减小)的变化规律,因此在研究函数问题时,如果涉及到函数 Function is one of the main contents of high school mathematics. The function thought is also one of the main mathematical ideas in high school mathematics. It is not only the focus but also the difficult point of high school review. It is also one of the hot topics in college entrance examination. Among them, the monotonicity of the function is to reflect the variation of the function value increasing (or decreasing) with the increase of the independent variable. Therefore, when studying the function problem, if the function