Evaluate Riemann Sum for the given function, a good way to convince yourself about integrals

RiemannSums.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace RiemannSums
{
    class Program
    {
        static double f( double x)
        {
            return x * x;

        }

        static double g(double x)
        {
            return 2*x * x + 3*x + 7;

        }

        static void Main(string[] args)
        {
            Console.WriteLine(" x^2 from {0} to {1} with {3} cuts is {2}",0, 5, RiemannSumOf(f, 0, 5, 25 ),25);

            Console.WriteLine(" x^2 from {0} to {1} with {3} cuts is {2}", 0, 5, RiemannSumOf(f, 0, 5, 40),40);

            Console.WriteLine(" x^2 from {0} to {1} with {3} cuts is {2}", 0, 5, RiemannSumOf(f, 0, 5, 80),80);

            Console.WriteLine(" x^2 from {0} to {1} with {3} cuts is {2}", 0, 5, RiemannSumOf(g, 0, 5, 25), 25);

            Console.WriteLine(" x^2 from {0} to {1} with {3} cuts is {2}", 0, 5, RiemannSumOf(g, 0, 5, 40), 40);

            Console.WriteLine(" x^2 from {0} to {1} with {3} cuts is {2}", 0, 5, RiemannSumOf(g, 0, 5, 80000), 80000);

        }

        /*
         *  Uses Left End point method
         */
        static double RiemannSumOf( Func<double,double> func, double from , double to, int cuts)
        {
            double area = 0.0d;

            int currentRect = 0;

            double range = to - from;

            double width = range/cuts;

            double lastPoint = from;

            while (currentRect != cuts)
            {
                currentRect++;

                area += width * func((lastPoint + width));

                lastPoint += width;
            }

            return area;
        }
    }
}