求解函数中参数范围问题一般有函数最值法(或函数上、下界法)、参变量分离法、函数图象法等方法.许多同学一见到这类问题,就会套用这些方法.但方法是死的,人的思想是活的.有时方法很多,但只会机械运用,还是对付不了新的题型.因此仅仅掌握方法是不够的,只有充分理解这些方法背后鲜活的数学思想,才 Solving the parameters in the function of the range of problems generally have the function of the most value method (or function, the lower bound method), parametric separation method, the function of the image method, etc. Many students will see these kinds of problems, they will apply these methods. Is dead, and people’s minds are alive. Sometimes there are many ways, but only mechanical use or new problems can not be dealt with. Therefore, it is not enough to master the method. Only by fully understanding the fresh mathematical thinking behind these methods,