C语言 自定义函数求一元二次方程&

解题思路:

注意事项:

参考代码:

#include<stdio.h>

#include<math.h>

int main()

{  

    void delta_day_0(double delta, double a, double b, double c);

    void delta_dy_0(double delta, double a, double b, double c);

    void delta_xy_0(double delta, double a, double b, double c);

    double a, b, c, delta;

    scanf("%lf %lf %lf", &a, &b, &c);

    delta = pow(b,2) - 4 * a * c;

    if (delta > 0)delta_day_0(delta, a, b, c);

    else if (delta == 0)delta_dy_0(delta,a,b,c);

    else if (delta < 0)delta_xy_0(delta,a,b,c);

    return 0;    

}

void delta_day_0(double delta,double a, double b, double c)

{

    double x1, x2;

    x1 =(b + sqrt(delta)) /( (-2)*a);

    x2 = (b - sqrt(delta))/ ((-2) * a);

    printf("x1=%.3lf x2=%.3lf", x1, x2);

}

void delta_dy_0(double delta, double a, double b, double c)

{

    double x1, x2;

    x1=x2=(b + sqrt(delta) )/ ((-2) * a);

    printf("x1=%.3lf x2=%.3lf", x1, x2);

}

void delta_xy_0(double delta, double a, double b, double c)

{

    double x1,x1i, x2,x2i;

    x1 = b / ((-2) * a);

    x1i = sqrt(-delta) / ((-2) * a);

    x2 = b / ((-2) * a);

    x2i =-sqrt(-delta) / ((-2) * a);

    printf("x1=%.3lf+%.3lfi x2=%.3lf%.3lfi", x2, x2i, x1, x1i);

}