tanh, tanhf, tanhl - hyperbolic tangent function
#include <math.h>
double tanh(double x);
float tanhf(float x);
long double tanhl(long double x);
Link with
-lm.
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 versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
These functions return the hyperbolic tangent of
x, which is defined
mathematically as:
tanh(x) = sinh(x) / cosh(x)
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.
No errors occur.
For an explanation of the terms used in this section, see
attributes(7).
| Interface |
Attribute |
Value |
| tanh (), tanhf (), tanhl () |
Thread safety |
MT-Safe |
C99, POSIX.1-2001, POSIX.1-2008.
The variant returning
double also conforms to SVr4, 4.3BSD, C89.
acosh(3),
asinh(3),
atanh(3),
cosh(3),
ctanh(3),
sinh(3)