public class X {    public static void main(String[] args) {        double a = 1.0;        double b = 3.0;        double c = -4.0;        double r1 = (-b + Math.sqrt(Math.pow(b,2) - 4 * a * c)) / 2 * a;        double r2 = (-b - Math.sqrt(Math.pow(b,2) - 4 * a * c)) / 2 * a;        System.out.println(r1);        System.out.println(r2);        System.out.println(r1 == 1 && r2 == -4?"测试通过":"测试不通过");    }}