用C语言程序求解ax*x+b*x+c=0是怎样的？

for(x=0;x<100;i++)//根据x的取值范围来限定即可
if(a*x*x+b*x*c==0)
break;
printf("x=%d",x);

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

int main(void)
{
float a, b, c;
printf("input a, b, c:");
scanf("%f,%f,%f", &a, &b, &c);

float x1, x2;
if(!(a>-0.000001 && a < 0.000001))
{
x1 = (-b + sqrt(b*b - 4 * a * c)) / 2 * a;
x2 = (-b - sqrt(b*b - 4 * a * c)) / 2 * a;
}
else
{
x1 = x2 = (-b)/2 * a;
}

printf("x1 = %f, x2 = %f", x1, x2);

return 0;
}

哎学了忘，忘了学。