/** 
 * quad.c - Use the quadratic formula!
 */
 
/* import the standard input-output library */
#include <stdio.h>
/* import the math library */
#include <math.h>

/* define the main method */
int main(void)
{
	/* define the variables we will use */
	/* ax^2 + bx + c = 0 */
	double a; 
	double b;
	double c;
	
	/* prompt for an input of a */
	printf("Enter coefficient for x^2: ");
	
	/* input the value for a */
	scanf("%lf", &a); /* doubles need the %lf placeholder! */
	
	/* prompt for an input of b */
	printf("Enter coefficient for x: ");
	
	/* input the value for b */
	scanf("%lf", &b);
	
	/* prompt for an input of c */
	printf("Enter constant: ");
	
	/* input the value for c */
	scanf("%lf", &c);
	
	/* use these values to calculate portions of the quadratic formula */
	
	/* b^2 - 4ac */
	double discriminant = b*b - 4.0L * a * c;
	
	/* sqrt(b^2 - 4ac) */
	double disc_sqrt = sqrt(discriminant);
	
	/* first root, with a + */
	double root1 = (-b + disc_sqrt)/(2.0L * a);
	
	/* second root, with a - */
	double root2 = (-b - disc_sqrt)/(2.0L * a);
	
	/* output the roots */
	printf("Roots are %lf and %lf.\n", root1, root2); 
	/* included \n since not expecting input */

	/* program over, return 0 for no errors! */	
	return 0;
}
/* main method over, done! */