以三次函数为载体的试题,可综合考察导数,函数,方程,不等式和曲线等知识,是近年高考试题的一大亮点.笔者统计,在2005年全国高考的16套(特别是文科卷)试题中,直接或间接考察三次函数的问题有北京卷、天津卷、重庆卷、全国卷Ⅰ、全国卷Ⅱ等共14道,因此特介绍三次函数的单调性问题 The questions on the basis of the cubic function can comprehensively examine the derivatives, functions, equations, inequalities and curves, etc. It is a major highlight of the high exam questions in recent years. According to the author’s statistics, 16 sets (especially liberal arts volumes) of the national college entrance examination questions in 2005 Among them, the direct or indirect examination of the cubic functions includes 14 volumes such as Beijing, Tianjin, Chongqing, National I, and National II. Therefore, the monotonicity of the cubic function is introduced.