//  Решение квадратного уравнения.
//  Solving a quadratic  equation.


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

float   a,
        b,
        c,
       x1,
       x2,
        D,                         //  discriminant
      res;                  // sqrt of discriminant

////////////////////////////////////////////////////
int main()                                        //
{

    printf("a = "); scanf("%f", &a);
    printf("b = "); scanf("%f", &b);
    printf("c = "); scanf("%f", &c);

    D = (b*b) - (4*a*c);

    if(D < 0) {

       printf("\nDiscriminant < 0, no root.");
       return 0;
    }

    res = sqrt(D);

    if(D > 0) {

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

       printf("\nDiscriminant > 0 (2 root's): \n");
       printf("x1 = %6.2f \n", x1);
       printf("x2 = %6.2f \n", x2);       return 0;
    }

    x1 = (-b)/(2 * a);

    printf("\nDiscriminant = 0, only one solution. \n");
    printf("x = %.2f", x1);

return 0;
}