论文部分内容阅读
含有参数的函数不等式恒成立时,求参数的取值范围问题,是高考的热点和难点问题.解法因题而异多种多样,其中有一类题目条件设置巧妙,试题隐藏一个相同信息:不等式等号恰好在区间端点处成立,这一隐而不露的条件是命题人精心设计的点睛之笔,也是解题者解决问题的突破口和思维的起点.它启发解题者思考:若函数在区间上单调,则不等式恒成立,从而求出参数的取值范围,这个取值范围就是不等式恒成立的充分条件.
When the function inequality with parameters is constant, the problem of finding the range of values of the parameters is the hot and difficult problem of the college entrance examination. The solution varies from subject to question, among which one class of problem conditions is ingenious, and the test item hides the same information: inequality, etc. The number is set right at the end of the interval. This hidden condition is the punctuation of the propositional person’s careful design, and it is also the breakthrough point and the starting point for the solver to solve the problem. It enlightens the solver to think: If the function is in the interval Monotonically, the inequality holds and the range of values of the parameters is found. This value range is a sufficient condition for the inequality to hold.