Hello. I am extremely new to C. I am trying to write a simple program that will determine the zeros of a quadratic function. I have a couple of problems.

Code:

#include <stdio.h>
#include <math.h>
int main ( int argc, const char * argv[] ) {
float a; // a;
float b; // b;
float c; // c;
float x1; // x1;
float x2; // x2;
float disc; // discriminant;
printf( "a = " );
scanf( "%f", &a );
fpurge( stdin );
printf( "b = " );
scanf( "%f", &b );
fpurge( stdin );
printf( "c = " );
scanf( "%f", &c );
fpurge( stdin );
disc = ( b * b ) - ( 4 * a * c );
x1 = ( ( -1 * b ) + sqrt(disc) ) / ( 2 * a );
x2 = ( ( -1 * b ) - sqrt(disc) ) / ( 2 * a );
if ( disc > 0 ) {
printf( "%f, %f", &x1, &x2 );
}
else if ( disc == 0 ) {
}
else if ( disc < 0 ) {
printf( "No real solutions." );
}
return 0;
}

Once I get a, b, and c, I can determine the discriminant. If the discriminant is positive, there are 2 solutions (x1 and x2), if it is 0, there is 1 solution (x1 or x2), and if it is negative, there are no solutions. I have 2 problems.

First of all, when I test the program with an equation that should give me two numbers, it gives me 0 and 0 (and it's not supposed to be).

My other problem is when the discriminant is 0. I don't know if x1 or x2 will give me the correct answer. How can I determine which one is right?

Thanks in advance!