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# tan, tanf, tanh, tanhf

Visual Studio .NET 2003

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
);
```

x

#### Return Value

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
± &infin;
(tan, tanf)
INVALID _DOMAIN

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

#### Remarks

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.

#### Requirements

tan, tanf, tanh, tanhf <math.h> ANSI, Win 98, Win Me, Win NT, Win 2000, Win XP

For additional compatibility information, see Compatibility in the Introduction.

Libraries

All versions of the C run-time libraries.

#### Example

```// 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
```