using System;
using System.Numerics;
public class Example
{
public static void Main()
{
Complex[] values = { new Complex(2.5, 1.5), new Complex(-2.5, -1.5) };
foreach (Complex value in values)
Console.WriteLine("Tan(Atan({0})) = {1}",
value, Complex.Tan(Complex.Atan(value)));
}
}