本文重点讨论一类形如y=af~2(x)+bf(x)+c的二次型复合函数问题,通过探究函数y=f[f(x)]与y=f(x)的内在联系,利用换元法对比两个函数图象,给出一种求解不同设问形式下上述问题的通用图象解法.例1已知函数f(x)=x~3+ax~2+bx+c This paper focuses on the problem of a quadratic complex function of the form y = af ~ 2 (x) + bf (x) + c. In this paper, a general image method for solving the above problems under different forms of questioning is given by comparing the two function images with the method of invariance.Example 1 It is known that the function f (x) = x ~ 3 + ax ~ 2 + bx + c