/*
 * program to compute (real) roots of quadratic equation
 *
 * must compile with "-lm" flag to get sqrt()
 */
#include <stdio.h>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>

int main(void) {
    double a;
    double b;
    double c;

    double root1;
    double root2;
    double temp;

    printf("enter coefficients:\n");
    if (scanf("%lf %lf %lf", &a, &b, &c) != 3) {
        printf("not numeric input\n");
        exit(1);
    }

    if (a == 0) {
        if (b == 0) {
            printf("oh be real (a and b both zero is not sensible!)\n");
        }
        else {
            root1 = -c / b;
            printf("root is %f\n", root1);
        }
    }
    else {
        temp = b*b - 4*a*c;
        if (temp < 0) {
            printf("no real roots\n");
        }
        else {
            root1 = (-b + sqrt(temp)) / (2*a);
            root2 = (-b - sqrt(temp)) / (2*a);
            printf("roots are %f, %f\n", root1, root2);
        }
    }

    return 0;
}