title: System.Math un identified
body: <pre><code>using System;    
  using System.Math;    
  class test
  
    {    
      public static void Main()    
        {    
          Console.Write("Enter any  value: ");    
          string s=Console.ReadLine();    
          double n = double.Parse(s);    
          double r = Math.sqrt(n);    
          Console.WriteLine(r);    
          Console.ReadKey();    
        }    
    }
  </code></pre>
  
  <p>I feel that every thing is clear in this code, but this code is giving compile errors:<br>
  A using namespace directive can only be applied to namespaces; 'System.Math' is a type not a namespace  </p>
  
  <p>How to use math functions?
  Where do we get a list of all math functions available in Math class?</p>
  
  <p>Thank You.</p>