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# tan, tanf, tanh, tanhf

Visual Studio 2005

Calculate the tangent (tan or tanf) or hyperbolic tangent (tanh or tanhf).

```
double tan(
double x
);
float tan(
float x
);  // C++ only
long double tan(
long double x
);  // C++ only
float tanf(
float x
);
double tanh(
double x
);
float tanh(
float x
);  // C++ only
long double tanh(
long double x
);  // C++ only
float tanhf(
float x
);
```

#### Parameters

x

tan returns the tangent of x. If x is greater than or equal to 263, or less than or equal to –263, a loss of significance in the result occurs.

Input SEH Exception Matherr Exception

± QNAN,IND

none

_DOMAIN

± ∞ (tan, tanf)

INVALID

_DOMAIN

tanh returns the hyperbolic tangent of x. There is no error return.

C++ allows overloading, so users can call overloads of tan and tanh that take float or long double types. In a C program, the tan and tanh functions always take and return double.

tan, tanf, tanh, tanhf

<math.h>

ANSI, Windows 95, Windows 98, Windows 98 Second Edition, Windows Millennium Edition, Windows NT 4.0, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003

For additional compatibility information, see Compatibility in the Introduction.

```// crt_tan.c
// This program displays the tangent of pi / 4
// and the hyperbolic tangent of the result.
//

#include <math.h>
#include <stdio.h>

int main( void )
{
double pi = 3.1415926535;
double x, y;

x = tan( pi / 4 );
y = tanh( x );
printf( "tan( %f ) = %f\n", pi/4, x );
printf( "tanh( %f ) = %f\n", x, y );
}
```

#### Output

```tan( 0.785398 ) = 1.000000
tanh( 1.000000 ) = 0.761594```