title: CS5001: exe does not contain a static 'Main' method suitable for an entry point
body: <pre><code>using System;
  
  public class Newton_Ralphson
  {
      public double compute(double x,int n,double[] P)            // x, degree, coefficients 
      {
          double pol = 0;
          for (int i = 0;i &lt; n;i++)
          {
              for (int j = 1; j &lt; n - i; j++)
                  x *= x;
                  pol += P[n - i] * x;
          }
          pol += P[0];
          return pol;
      }
  
  public double[] secondary_Pol(int n, double[] P)            //slope
  {
      double[] secP = new double[n - 1];
      for (int i = 0; i &lt; n - 1; i++) 
          secP[i] = P[i + 1];
      return secP;
  }
  
  public double Main()
  {
      Console.WriteLine("Estimate the solution for a nth degree polynomial!!! ");
      int n = 0;
      Console.WriteLine("Enter the degree of the polynomials! ");
      n = Int32.Parse(Console.ReadLine());
      double[] coefficients = new double[n+1];
  
      for(int i = 0;i &lt; n+1;i++)
      {
          Console.WriteLine("Enter the coefficients ");
          Console.Write("coefficients of x to the power of {0}: ", n - i);         //decending coefficients 
          coefficients[n-i] = Convert.ToDouble(Console.ReadLine());
      }
  
  
      Console.WriteLine("Initial value is: ");
      double xint = Convert.ToDouble(Console.ReadLine());
  
      Console.WriteLine("How many times does the function go through? ");
      int precision = Convert.ToInt32(Console.ReadLine());
      double polyValue = 0;
  
      for (int j = 0; j &lt; precision; j++)
      {
          polyValue = compute(xint, n, coefficients);                              //y0 in y = slope(x-x0) + y0
          double slope = compute(xint, n - 1, secondary_Pol(n, coefficients));
          xint = (-polyValue / slope) + xint;
      }
      Console.WriteLine(xint);
      Console.ReadLine();
      return 0;
  }
  </code></pre>
  
  <p>}</p>
  
  <p>When I add 'static' into the line: public static double Main()
  there is another error showed up </p>
  
  <p>error CS0120: An object reference is required for the non-static field, method, or property 'Newton_Ralphson.compute(double, int, double[])' </p>
  
  <p>error occurred when the two other function executed</p>