NAME
tanh, tanhf, tanhl - hyperbolic tangent function
SYNOPSIS
#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(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600
|| _ISOC99_SOURCE; or cc -std=c99
DESCRIPTION
The tanh() function returns 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.
CONFORMING TO
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)
COLOPHON
This page is part of release 3.24 of the Linux man-pages project. A
description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
2008-08-05