本文给出求解“多变量”不等式恒成立问题的通性通法,有利于迅速转化问题,提高解题技能.常见类型一:遇到涉及“对于任意的x1,x2∈D,都有f(x1)-f(x2)≤k(k为正常数)恒成立”问题,可转化为先求函数f(x)在区间D上的最大值和最小值;然后根据f(x1)-f(x2)≤f(x)max-f(x)min(x∈D)即可顺利求解. In this paper, we give a general method for solving the problem of “multivariate ” inequalities, which is good for rapidly transforming problems and improving problem solving skills. There is a constant f (x1) -f (x2) ≤k (k is a constant), which can be transformed into the maximum and minimum of the function f (x) in the interval D. Then, ) -f (x2) ≤ f (x) max-f (x) min (x∈D) can be solved smoothly.