Simple RPN calculator

using System;
using System.Collections.Generic;

// DM 14/nov/2014
namespace TestFuncDelegate
{
    class Program
    {
        static public Dictionary<string, Func<double, double, double>> dict = new Dictionary<string, Func<double, double, double>>();

        static void Main(string[] args)
        {
            InitDictionary();
            Console.WriteLine("          ++++ Simple RPN calculator ++++");
            Console.WriteLine();
            Console.WriteLine(" Approximation of pi: 355.0/113.0 = {0}", do_op("/", 355, 113));
            Console.WriteLine(" Square root of 25 = {0}", do_op("**", 25, 0.5));
            Console.WriteLine(" The addition of {0} and {1} equals {2}", 2.3, 8.18, do_op("+", 2.3, 8.18));
            Console.WriteLine(" The sine of an angle of 30° = {0}", do_op("sin", Math.PI/6, 0));
            Console.WriteLine(" The arcsine of a sine: {0}" , do_op("asin", do_op("sin", 0.7, 0), 0));
            Console.WriteLine(" The hypothenuse of a right triangle with sides 3 and 4:  {0}",do_op("hypo", 3, 4));
            Console.ReadKey();
        }

        static public void InitDictionary()
        {
            // Other way, more verbose but perhaps clearer?
            // Func<double, double, double> AddFunc = (x, y) => x + y;
            // dict.Add("+", AddFunc);

            // Shorter, let compiler worry about Func delegates.
            dict.Add("+", (x, y) => x + y);            
            dict.Add("-", (x, y) => x - y);            
            dict.Add("*", (x, y) => x * y);
            dict.Add("/", (x, y) => x / y);
            dict.Add("//", (x, y) => Math.Floor(x / y));
            dict.Add("**", (x, y) => Math.Pow(x,y));
            dict.Add("sin", (x, y) => Math.Sin(x));  // y dummy
            dict.Add("cos", (x, y) => Math.Cos(x));  // y dummy
            dict.Add("tan", (x, y) => Math.Tan(x));  // y dummy
            dict.Add("asin", (x, y) => Math.Asin(x));  // y dummy
            dict.Add("acos", (x, y) => Math.Acos(x));  // y dummy
            dict.Add("atan", (x, y) => Math.Atan(x));  // y dummy
            dict.Add("hypo", (x, y) => Math.Sqrt(x * x + y * y));  // y dummy
        }

        static public double do_op(string oper,double x, double y)
        {
            try
            {
                double result;
                Func<double, double, double> theFunc;
                dict.TryGetValue(oper, out theFunc);
                result = theFunc(x, y);
                return result;
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
                return double.NaN;
            }                     
        }
    }
}