#include <stdio.h> #include <math.h> // 待求极值的函数 double f(double x) { return pow(x, 3) - 2 * pow(x, 2) + 3 * x - 1; } // 求函数在x处的导数 double df(double x, double h) { return (f(x + h) - f(x - h)) / (2 * h); } // 求函数的极值 double find_extremum(double a, double b, double eps) { double x0, x1, x2, h; x1 = a; x2 = b; h = 0.001; do { x0 = x1; x1 = x2; x2 = x1 - df(x1, h) / ((df(x1, h) - df(x0, h)) / (x1 - x0)); } while (fabs(x2 - x1) >= eps); return x2; } int main() { double a, b, eps; printf("请输入区间[a, b]和精度eps：\n"); scanf("%lf %lf %lf", &a, &b, &eps); double x = find_extremum(a, b, eps); printf("函数的极值点为：%lf\n", x); printf("函数的极值为：%lf\n", f(x)); return 0; }加注释

#include <stdio.h>
#include <math.h>

// 待求极值的函数
double f(double x) {
    return pow(x, 3) - 2 * pow(x, 2) + 3 * x - 1;
}

// 求函数在x处的导数
double df(double x, double h) {
    return (f(x + h) - f(x - h)) / (2 * h);
}

// 求函数的极值
double find_extremum(double a, double b, double eps) {
    double x0, x1, x2, h;
    x1 = a;
    x2 = b;
    h = 0.001;
    do {
        x0 = x1;
        x1 = x2;
        // 使用牛顿迭代法求解极值点
        x2 = x1 - df(x1, h) / ((df(x1, h) - df(x0, h)) / (x1 - x0));
    } while (fabs(x2 - x1) >= eps);
    return x2;
}

int main() {
    double a, b, eps;
    // 获取区间和精度
    printf("请输入区间[a, b]和精度eps：\n");
    scanf("%lf %lf %lf", &a, &b, &eps);
    // 调用函数求解
    double x = find_extremum(a, b, eps);
    printf("函数的极值点为：%lf\n", x);
    printf("函数的极值为：%lf\n", f(x));
    return 0;
}