近几年高考,函数中双变量的任意与存在混搭的等式问题,越来越受命题人的青睐.对于这类问题,学生很是困惑.下面就此类问题总结归纳如下:命题1x_1∈A,■x_2∈B,使得f(x_1)=g(x_2)成立{f(x)|x∈A}的值域含于g(x)的值域{f(x)|x∈A}■{g(x)|x∈B}.命题2x_1∈A,x_2∈B,都有f(x_1) In recent years, college entrance examination, the function of the bivariate arbitrariness and the existence of the mashup equation problems, more and more favored by the proponents .For such problems, the students are very confused. The following is a summary of these issues are summarized as follows: Proposition 1x_1 ∈A, ■ x_2∈B such that the range of f (x_1) = g (x_2) holds for {f (x) | x∈A} is contained in the range of ({f (x) | x ∈A} ■ {g (x) | x∈B}. Propositions 2x_1∈A, x_2∈B, all have f (x_1)