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Math::Tanh Method

Returns the hyperbolic tangent of the specified angle.

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

public:
static double Tanh(
	double value
)

Parameters

value
Type: System::Double

An angle, measured in radians.

Return Value

Type: System::Double
The hyperbolic tangent of value. If value is equal to NegativeInfinity, this method returns -1. If value is equal to PositiveInfinity, this method returns 1. If value is equal to NaN, this method returns NaN.

The angle, value, must be in radians. Multiply by Math::PI/180 to convert degrees to radians.

The following example uses Tanh to evaluate certain hyperbolic tangent identities for selected values.

// Example for the hyperbolic Math::Tanh( double ) method. 
using namespace System;

// Evaluate hyperbolic identities with a given argument. 
void UseTanh( double arg )
{
   double tanhArg = Math::Tanh( arg );

   // Evaluate tanh(X) == sinh(X) / cosh(X).
   Console::WriteLine( "\n                        Math::Tanh({0}) == {1:E16}\n" 
   "      Math::Sinh({0}) / Math::Cosh({0}) == {2:E16}", arg, tanhArg, (Math::Sinh( arg ) / Math::Cosh( arg )) );

   // Evaluate tanh(2 * X) == 2 * tanh(X) / (1 + tanh^2(X)).
   Console::WriteLine( "                    2 * Math::Tanh({0}) /", arg, 2.0 * tanhArg );
   Console::WriteLine( "              (1 + (Math::Tanh({0}))^2) == {1:E16}", arg, 2.0 * tanhArg / (1.0 + tanhArg * tanhArg) );
   Console::WriteLine( "                        Math::Tanh({0}) == {1:E16}", 2.0 * arg, Math::Tanh( 2.0 * arg ) );
}


// Evaluate a hyperbolic identity that is a function of two arguments. 
void UseTwoArgs( double argX, double argY )
{

   // Evaluate tanh(X + Y) == (tanh(X) + tanh(Y)) / (1 + tanh(X) * tanh(Y)).
   Console::WriteLine( "\n    (Math::Tanh({0}) + Math::Tanh({1})) /\n" 
   "(1 + Math::Tanh({0}) * Math::Tanh({1})) == {2:E16}", argX, argY, (Math::Tanh( argX ) + Math::Tanh( argY )) / (1.0 + Math::Tanh( argX ) * Math::Tanh( argY )) );
   Console::WriteLine( "                        Math::Tanh({0}) == {1:E16}", argX + argY, Math::Tanh( argX + argY ) );
}

int main()
{
   Console::WriteLine( "This example of hyperbolic Math::Tanh( double )\n" 
   "generates the following output." );
   Console::WriteLine( "\nEvaluate these hyperbolic identities " 
   "with selected values for X:" );
   Console::WriteLine( "   tanh(X) == sinh(X) / cosh(X)" );
   Console::WriteLine( "   tanh(2 * X) == 2 * tanh(X) / (1 + tanh^2(X))" );
   UseTanh( 0.1 );
   UseTanh( 1.2 );
   UseTanh( 4.9 );
   Console::WriteLine( "\nEvaluate [tanh(X + Y) == " 
   "(tanh(X) + tanh(Y)) / (1 + tanh(X) * tanh(Y))]" 
   "\nwith selected values for X and Y:" );
   UseTwoArgs( 0.1, 1.2 );
   UseTwoArgs( 1.2, 4.9 );
}

/*
This example of hyperbolic Math::Tanh( double )
generates the following output.

Evaluate these hyperbolic identities with selected values for X:
   tanh(X) == sinh(X) / cosh(X)
   tanh(2 * X) == 2 * tanh(X) / (1 + tanh^2(X))

                        Math::Tanh(0.1) == 9.9667994624955819E-002
      Math::Sinh(0.1) / Math::Cosh(0.1) == 9.9667994624955819E-002
                    2 * Math::Tanh(0.1) /
              (1 + (Math::Tanh(0.1))^2) == 1.9737532022490401E-001
                        Math::Tanh(0.2) == 1.9737532022490401E-001

                        Math::Tanh(1.2) == 8.3365460701215521E-001
      Math::Sinh(1.2) / Math::Cosh(1.2) == 8.3365460701215521E-001
                    2 * Math::Tanh(1.2) /
              (1 + (Math::Tanh(1.2))^2) == 9.8367485769368024E-001
                        Math::Tanh(2.4) == 9.8367485769368024E-001

                        Math::Tanh(4.9) == 9.9988910295055444E-001
      Math::Sinh(4.9) / Math::Cosh(4.9) == 9.9988910295055433E-001
                    2 * Math::Tanh(4.9) /
              (1 + (Math::Tanh(4.9))^2) == 9.9999999385024030E-001
                        Math::Tanh(9.8) == 9.9999999385024030E-001

Evaluate [tanh(X + Y) == (tanh(X) + tanh(Y)) / (1 + tanh(X) * tanh(Y))]
with selected values for X and Y:

    (Math::Tanh(0.1) + Math::Tanh(1.2)) /
(1 + Math::Tanh(0.1) * Math::Tanh(1.2)) == 8.6172315931330645E-001
                        Math::Tanh(1.3) == 8.6172315931330634E-001

    (Math::Tanh(1.2) + Math::Tanh(4.9)) /
(1 + Math::Tanh(1.2) * Math::Tanh(4.9)) == 9.9998993913939649E-001
                        Math::Tanh(6.1) == 9.9998993913939649E-001
*/

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune

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

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 3.5, 2.0, 1.0

XNA Framework

Supported in: 3.0, 2.0, 1.0

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