求一元二次方程的解

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<math.h>
# define EXP 0.000000001
int  main()
{
double a, b, c;
scanf("%lf,%lf,%lf", &a, &b, &c);
if((a > -EXP) && (a < EXP))
{
printf("不是一元二次方程\n");
}
else
{
double disc = b*b - 4 * a*c;
if ((disc>-EXP) && (disc < EXP))
{
double x = -b / (2 * a);
printf("x1=x2=%lf\n", x);
}
else if (disc>0.0)
{
double x1 = (-b + sqrt(disc) / (2 * a));
double x2 = (-b - sqrt(disc) / (2 * a));
printf("x1=%lf\n", x1);
printf("x2=%lf\n", x2);
}
else
{
printf("有两个共轭复根");


}
system("pause");
return  0;
}
}