#include       <stdio.h>

#include       <math.h>


float D   =  81.0,
      a   = 2,
      b   = 8,
      c   = 0,
      res = 0.2;



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

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

    if(D < 0)
    {

       printf("D = %.2f  (less than zero) \n", D);
       printf("No solution ! \n");
       return 0;
    }

    res = sqrt(D);

    printf("sqrt %.2f = %.2f", D, res);

}