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Complex.Cos Method

Returns the cosine of the specified complex number.

Namespace:  System.Numerics
Assembly:  System.Numerics (in System.Numerics.dll)

Public Shared Function Cos ( _
	value As Complex _
) As Complex


Type: System.Numerics.Complex
A complex number.

Return Value

Type: System.Numerics.Complex
The cosine of value.

The Cos method for complex numbers corresponds to the Math.Cos method for real numbers.

The Cos method uses the following formula to calculate the cosine of the complex number a + bi:

(Cos(a) * Cosh(b), -(Sin(a) * Sinh(b)))

The following example illustrates the Acos method. It shows that passing the value returned by the Acos method to the Cos method returns the original Complex value.

Imports System.Numerics

Module Example
   Public Sub Main()
      Dim values() As Complex = { New Complex(.5, 2), 
                                  New Complex(.5, -2),
                                  New Complex(-.5, 2),
                                  New Complex(-.3, -.8) }
      For Each value As Complex In values
         Console.WriteLine("Cos(ACos({0})) = {1}", value, 
   End Sub
End Module
' The example displays the following output:
'       Cos(ACos((0.5, 2))) = (0.5, 2)
'       Cos(ACos((0.5, -2))) = (0.5, -2)
'       Cos(ACos((-0.5, 2))) = (-0.5, 2)
'       Cos(ACos((-0.3, -0.8))) = (-0.3, -0.8)

.NET Framework

Supported in: 4

.NET Framework Client Profile

Supported in: 4

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.