函数是构建中学数学的主旋律.而函数思想在高中数学的运用较多.它起到承上启下的作用.在考虑到相关运动变化、相依关系的同时,以一类状态过渡至研究变化的过程,从而确立相关的思想方式.在高中数学的范畴,关于不等式的研究,如何才能体现相应的函数思想,培养学生应用函数解决不等式的问题,进一步挖掘培养学生的思维深刻性.为此,我们必须从问题分析开始,对函数思想加以论述,并详细地探究.笛卡尔的方程思想是:实际问题→数学问题→代数问题 Function is the main theme of constructing mathematics in middle school, while function thought is more used in high school mathematics, which plays the role of bearing on and off .At the same time taking into account the related movement and the dependence, the transition from one state to the study of the change process Establish the relevant way of thinking.In the field of high school mathematics, on the study of inequality, how to reflect the corresponding function ideas, training students to apply the function to solve the inequality problem, to further cultivate students’ profound thinking.To this end, we must from the problem The analysis begins with an elaboration of the functional idea and explores it in detail. Descartes’ equation ideas are: Practical Problems → Mathematical Problems → Algebraic Problems