补一补之前漏的
#include<stdio.h>
#include<math.h>
int main()
{
double a,b,c,d=0;
scanf("%lf%lf%lf",&a,&b,&c);
d=pow(b,2)-4*a*c;
if(d<0||a==0){
printf("Impossivel calcular");
}
else{
printf("R1 = %.5lf\nR2 = %.5lf",(-b+sqrt(d))/(2*a),(-b-sqrt(d))/(2*a));
}
return 0;
}