Below is the syntax highlighted version of Quadratic.java from §1.2 Built-in Types of Data.

/*************************************************************************

 *  Compilation:  javac Quadratic.java

 *  Execution:    java Quadatic b c

 *  

 *  Given b and c, solves for the roots of x*x + b*x + c.

 *  Assumes both roots are real valued.

 *

 *  % java Quadratic -3.0 2.0

 *  2.0

 *  1.0

 *

 *  % java Quadratic -1.0 -1.0

 *  1.618033988749895

 *  -0.6180339887498949

 *

 *  Remark:  1.6180339... is the golden ratio.

 *

 *  % java Quadratic 1.0 1.0

 *  NaN

 *  NaN

 *

 *

 *************************************************************************/

public class Quadratic { 

    public static void main(String[] args) { 

        double b = Double.parseDouble(args[0]);

        double c = Double.parseDouble(args[1]);

        double discriminant = b*b - 4.0*c;

        double sqroot =  Math.sqrt(discriminant);

        double root1 = (-b + sqroot) / 2.0;

        double root2 = (-b - sqroot) / 2.0;

        System.out.println(root1);

        System.out.println(root2);

    }

}