我们先给出迭代函数的概念:一般地,如果给定一个函数f(x),它的值域是其定义域的子集,那么我们可以记f~(1)(x)=f(x),f~(2)(x)=f(f(x)),f~(3)(x)=f(f(f(x))),……,f~(n)(x)=f(f~(n-1)(x))=(f(f(…f(x)…)))n个f并把它们依次叫做函数f(x)的一次迭代,二次迭代,三次迭代,……,n次迭代.n称为f(x)的迭代指数,显然,n次迭代就是同一函数的n次复合函数,下面讨论与二次迭代函数的零点 We first give the notion of an iterative function: In general, given a function f (x) whose value range is a subset of its domain, we can remember that f ~ (1) (x) = f (x ), f ~ (2) (x) = f (f (x)), f ~ (3) (x) = f (f = f (f ~ (n-1) (x)) = f (f (f (x) ...))) nf and call them sequentially one iteration of the function f (x) Three iterations, ..., n iterations .n An iteration index called f (x). Obviously, n iterations are the n-th complex functions of the same function. The following discussion deals with the zero point