一元二次方程公式

#include<stdio.h>
#include<math.h>
int main()
{

   double a,b,c,R1,R2;
   scanf("%lf %lf %lf",&a,&b,&c);
   double delta = b*b-4*a*c;
   if(delta<0||a==0)
       printf("Impossivel calcular");
   else
   {
       R1 = (-b+sqrt(delta))/(2*a);
       R2 = (-b-sqrt(delta))/(2*a);
       printf("R1 = %.5lf\nR2 = %.5lf",R1,R2);

   }
   return 0;
}