All Roots of a Quadratic Equation

#include<stdio.h>
#include<math.h>
#include<conio.h>
//Quadratic equation
int main()
{
    // standard formula ax2 + bx + c = 0
    /*the special Quadratic Formula:
    x = [ -b (+-) sqrt(b^2 - 4ac) ] / 2a */
    double a,b,c,d,x1,x2;

    printf("Enter a,b,c:\n");
    scanf("%lf %lf %lf",&a,&b,&c);

    d=sqrt(b*b-4*a*c);
    x1=(-b+d)/(2*a);
    x2=(-b-d)/(2*a);

    printf("x1=%.0lf\n",x1);
    printf("x2=%.0lf",x2);
     return 0;
}