C de ax^2+bx+c Denklemin Köklerini Bulan Kod

//www.ethemsulan.com
#include <stdio.h>  
#include <stdlib.h>
#include <math.h>
 int main()
{ 
    double x1,x2,a,b,dlt,c;
   printf("\na=");
   scanf("%lf",&a);
   printf("\nb=");
   scanf("%lf",&b);
   printf("\nc=");
   scanf("%lf",&c);
    dlt=b*b-4*a*c;
    if (dlt<0){
    printf("gercek kok yok\n");            
               }
   else if(dlt==0){
              x1=(-b)/(2*a);
printf("x1=x2=\n%lf\n",x1);          
              }
    else {
       x1=(-b+sqrt(dlt))/(2*a);
       x2=(-b-sqrt(dlt))/(2*a);
       printf("x1=%lf\n",x1);
       printf("x2=%lf\n",x2);
               }
              system("PAUSE");
              return (0);
             }