不等式恒成立求参数取值范围问题:最常使用的方法是分离参数求最值,即要使a≥g(x)恒成立,只需a≥g(x)max,要使a≤g(x)恒成立,只需a≤g(x)min,另外,当参数不宜进行分离时,还可直接求最值建立关于参数的不等式求解,例如:要使不等式f(x)≥0恒成立,可求得f(x)的最小值h(a),令h(a)≥0即可 Inequality Constants to establish the value range of parameters Problem: The most commonly used method is to find the maximum value of separation parameters, that is, to make a ≥ g (x) constant holds, as long as a ≥ g (x) max, x) constant, only a≤g (x) min. In addition, when the parameters are not suitable for separation, the inequality of the parameters can also be established by solving directly. For example, to make the inequality f , The minimum h (a) of f (x) can be obtained, and h (a) ≥0 can be obtained