# Complex.Cos(Complex) Méthode

## Définition

Retourne le cosinus du nombre complexe spécifié.Returns the cosine of the specified complex number.

``````public:
static System::Numerics::Complex Cos(System::Numerics::Complex value);``````
``public static System.Numerics.Complex Cos (System.Numerics.Complex value);``
``static member Cos : System.Numerics.Complex -> System.Numerics.Complex``
``Public Shared Function Cos (value As Complex) As Complex``

#### Paramètres

value
Complex

Nombre complexe.A complex number.

#### Retours

Cosinus de `value`.The cosine of `value`.

## Exemples

L’exemple suivant illustre la méthode Acos.The following example illustrates the Acos method. Elle indique que le passage de la valeur retournée par la méthode Acos à la méthode Cos retourne la valeur de Complex d’origine.It shows that passing the value returned by the Acos method to the Cos method returns the original Complex value.

``````using System;
using System.Numerics;

public class Example
{
public static void Main()
{
Complex[] values = { new Complex(.5, 2),
new Complex(.5, -2),
new Complex(-.5, 2),
new Complex(-.3, -.8) };
foreach (Complex value in values)
Console.WriteLine("Cos(ACos({0})) = {1}", value,
Complex.Cos(Complex.Acos(value)));
}
}
// 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)
``````
``````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,
Complex.Cos(Complex.Acos(value)))
Next
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)
``````

## Remarques

La méthode Cos pour les nombres complexes correspond à la méthode Math.Cos pour les nombres réels.The Cos method for complex numbers corresponds to the Math.Cos method for real numbers.

La méthode Cos utilise la formule suivante pour calculer le cosinus du nombre complexe a + bi :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)))(Cos(a) * Cosh(b), -(Sin(a) * Sinh(b)))