tanhl(3) Linux Man Page - System Grab Bag

Name

tanh, tanhf, tanhl - hyperbolic tangent function

Library

Math library ( libm ", " -lm )

Synopsis

#include <math.h> 
double tanh(double  x );
float tanhf(float  x );
long double tanhl(long double  x );

Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

tanhf() tanhl()

    _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
        || /* Since glibc 2.19: */ _DEFAULT_SOURCE
        || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

Description

These functions return the hyperbolic tangent of x, which is defined mathematically as:

    tanh(x) = sinh(x) / cosh(x)

Return Value

On success, these functions return the hyperbolic tangent of x.

If x is a NaN, a NaN is returned.

If x is +0 (-0), +0 (-0) is returned.

If x is positive infinity (negative infinity), +1 (-1) is returned.

Errors

No errors occur.

Attributes

For an explanation of the terms used in this section, see attributes(7). allbox; lbx lb lb T{ tanh()tanhf()tanhl()

Interface	Attribute	Value
T}	Thread safety	MT-Safe

Standards

C11, POSIX.1-2008.

History

C99, POSIX.1-2001.

The variant returning double also conforms to SVr4, 4.3BSD, C89.