—
NAME
tanh, tanhf, tanhl - hyperbolic tangent function
LIBRARY
Math library (libm, -lm)
SYNOPSIS
bash
#include <math.h>bash
double tanh(double \nx\n);\n
\nfloat tanhf(float \nx\n);\n
\nlong double tanhl(long double \nx\n);tanhf(), tanhl():
bash
\n
_ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
\n
|| /* Since glibc 2.19: */ _DEFAULT_SOURCE
\n
|| /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCEDESCRIPTION
These functions return the hyperbolic tangent of x, which is defined mathematically as:
bash
\n
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).
| Interface | Attribute | Value |
| tanh (), tanhf (), tanhl () | 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.
SEE ALSO
acosh(3), asinh(3), atanh(3), cosh(3), ctanh(3), sinh(3)