函数是高中数学的重要内容,教学时都是以基本函数为主,而考题中往往以形式比较复杂的函数出现(一般为复合函数),从而学生觉得比较难,笔者在此用几个典型学生易错题来阐释如何用复合函数的观点来处理函数中常见的三类问题.1用复合函数的观点处理函数值域问题原理分析复合函数y=f[g(x)],x∈D的值域问题,令u=g(x),x∈D称为内层函数,则y=f(u)称为外层函数,从而复合函数y=f[g(x)],x∈D由内层函数u=g(x),x∈D与外层函数y= Function is an important part of high school mathematics, teaching are based on basic functions, and test questions often appear in the form of more complex functions (usually complex functions), so students feel more difficult, I use a few typical students Easy to deal with the problem of how to deal with the complex function point of view to deal with the three common problems in the function.1 The concept of complex functions to deal with the problem of the value range problem Analysis of the composite function y = f [g (x)], x∈D Let u = g (x), x∈D be the inner function, then y = f (u) is called the outer function, thus the composite function y = f [g From the inner function u = g (x), x∈D and the outer function y =