我将牛顿函数移植到
double newton(double x_lower, double x_upper, double accuracy,
void (*f_pt)(double *f_value, double *f_derivative, double x));
f_pt指向计算f（x）和f＆＃39;（x）
的函数我开发功能
double f(double x);
double f_D(double x);
如何编写void (*f_pt)(double *f_value, double *f_derivative, double x)