Double - Atan

Returns the angle whose tangent is the specified number.

Try it

public static void Main()
{

    double angle;
    double radians;
    double result;

    // Calculate the tangent of 30 degrees.
    angle = 30;
    radians = angle * (Math.PI / 180);
	
	// C# Extension Method: Double - Tan
    result = radians.Tan();
    Console.WriteLine("The tangent of 30 degrees is {0}.", result);

    // Calculate the arctangent of the previous tangent.
	
	// C# Extension Method: Double - Atan
    radians = result.Atan();
    angle = radians * (180 / Math.PI);
    Console.WriteLine("The previous tangent is equivalent to {0} degrees.", angle);
}

View Source
using System;

public static partial class Extensions
{
    /// <summary>
    ///     Returns the angle whose tangent is the specified number.
    /// </summary>
    /// <param name="d">A number representing a tangent.</param>
    /// <returns>
    ///     An angle, ?, measured in radians, such that -?/2 ????/2.-or-  if  equals , -?/2 rounded to double precision (-
    ///     1.5707963267949) if  equals , or ?/2 rounded to double precision (1.5707963267949) if  equals .
    /// </returns>
    public static Double Atan(this Double d)
    {
        return Math.Atan(d);
    }
}