/**
 * Write a description of class MathExamples here.
 * 
 * @author John Paxton
 * @version 1.0
 */

public class MathExamples
{

    public static int factorial (int n)
    {
        if (n < 0)
        {
            System.out.println("Error - the number must not be negative");
            return -1;
        }
        else
        {
            return factorialAux (n);
        }
    }
    
    private static int factorialAux (int n)
    {
        if (n <= 0)
        {
            return 1;
        }
        else
        {
            return n * factorialAux(n - 1);
        }
    }
    
    public static int fibonacci (int n)
    {
        if (n <= 0)
        {
            return 0;
        }
        else if (n == 1)
        {
            return 1;
        }
        else
        {
            return fibonacci(n - 1) + fibonacci(n - 2);
        }
    }
}