c语言输入参数a,b,c，求一元二次方程ax2 +bx +c =0 的根。（带复根）

好的，这里给出计算一元二次方程根的C语言函数代码：

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

void quadratic_equation(double a, double b, double c) {
    double delta = b * b - 4 * a * c;
    if (delta > 0) {
        double x1 = (-b + sqrt(delta)) / (2 * a);
        double x2 = (-b - sqrt(delta)) / (2 * a);
        printf("x1 = %lf, x2 = %lf\n", x1, x2);
    } else if (delta == 0) {
        double x = -b / (2 * a);
        printf("x = %lf\n", x);
    } else {
        double real_part = -b / (2 * a);
        double imaginary_part = sqrt(-delta) / (2 * a);
        printf("x1 = %lf + %lfi, x2 = %lf - %lfi\n", real_part, imaginary_part, real_part, imaginary_part);
    }
}

int main() {
    double a, b, c;
    printf("请输入一元二次方程的系数：\n");
    printf("a = ");
    scanf("%lf", &a);
    printf("b = ");
    scanf("%lf", &b);
    printf("c = ");
    scanf("%lf", &c);
    quadratic_equation(a, b, c);
    return 0;
}

输入参数a、b、c后，调用quadratic\_equation函数计算方程的根并输出。如果delta大于0，方程有两个不等实根；如果delta等于0，方程有一个实根；如果delta小于0，方程有两个共轭复根。