tanh(3) Library Functions Manual tanh(3)
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).
┌────────────────────────────────────────────┬───────────────┬─────────┐
│ 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)
Linux man-pages 6.9.1 2024-05-02 tanh(3)
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