自2004年高中课程改革以来,以导数为工具讨论函数的单调性、求函数的极值和最值、存在性问题的探究、恒成立问题的解决、不等式的证明等成为高考试题的重点和热点。这类题目综合性强,难度很大,对数学思想方法的要求较高,考查学生综合运用数学知识分析问题和解决问题的能力。解决这类问 Since the 2004 high school curriculum reform, using the derivative as a tool to discuss the monotonicity of function, extremum and value of the function, exploring the existential problems, solving the problem of constant establishment, proving the inequality and so on become the focus and hot topic . These topics are comprehensive and difficult, they have high requirements on mathematical thinking and methodologies, and they examine the ability of students to use mathematical knowledge to analyze and solve problems synthetically. Solve this kind of question