`tanh`, `tanhf`, `tanhl`

Article
2023-02-17

Calculates the hyperbolic tangent.

Syntax

double tanh( double x );
float tanhf( float x );
long double tanhl( long double x );
#define tanh(x) // Requires C11 or higher

float tanh( float x );  // C++ only
long double tanh( long double x );  // C++ only

Parameters

x
Angle in radians.

Return value

The tanh functions return the hyperbolic tangent of x. There's no error return.

Input	SEH exception	`_matherr` exception
± QNaN, IND	none	`_DOMAIN`

Remarks

Because C++ allows overloading, you can call overloads of tanh that take and return float or long double values. In a C program, unless you're using the <tgmath.h> macro to call this function, tanh always takes and returns double.

If you use the tanh macro from <tgmath.h>, the type of the argument determines which version of the function is selected. See Type-generic math for details.

By default, this function's global state is scoped to the application. To change this behavior, see Global state in the CRT.

Requirements

Routine	Required header (C)	Required header (C)
`tanh`, `tanhf`, `tanhl`	`<math.h>`	`<cmath>` or `<math.h>`
`tanh` macro	`<tgmath.h>`

For more compatibility information, see Compatibility.

Example

// crt_tanh.c
// This program displays the tangent of pi / 4
// and the hyperbolic tangent of the result.
// Compile by using: cl crt_tanh.c

#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 );
}

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

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tanh, tanhf, tanhl