HP-UX Reference (11i v2 04/09) - 3 Library Functions N-Z (vol 7)

t
tanh(3M) tanh(3M)
NAME
tanh( ), tanhf( ), tanhl( ), tanhw( ), tanhq( ) - hyperbolic tangent functions
SYNOPSIS
#include <math.h>
double tanh(double x);
float tanhf(float x);
Itanium(R)-based System Only
long double tanhl(long double x);
extended tanhw(extended x);
quad tanhq(quad x);
DESCRIPTION
tanh() returns the hyperbolic tangent of x.
tanhf() is a float version of tanh(); it takes a
float argument and returns a float result.
Itanium-based System Only
tanhl() is a long double version of tanh(); it takes a long double argument and returns a
long double result.
tanhw() is an extended version of tanh(); it takes an extended argument and returns an
extended result.
tanhq() is equivalent to tanhl() on HP-UX systems.
USAGE
To use these functions, compile either with the default
-Ae option or with the -Aa
and the
-D_HPUX_SOURCE options.
To use (for Itanium-based systems)
tanhw() or tanhq(), compile also with the -fpwidetypes
option.
To use any of these functions, make sure your program includes
<math.h>, and link in the math library
by specifying -lm on the compiler or linker command line.
For more information, see the HP-UX Floating-Point Guide.
RETURN VALUE
tanh(±0) returns ±0.
If x is ±INFINITY,
tanh() returns ±1.0 respectively.
If x is NaN,
tanh() returns NaN.
Whether
tanh() raises the inexact exception is unspecified.
ERRORS
No errors are defined.
SEE ALSO
atanh(3M), cosh(3M), ctanh(3M), sinh(3M), math(5).
STANDARDS CONFORMANCE
tanh() : SVID3, XPG4.2, ANSI C, ISO/IEC C99 (including Annex F, ‘‘IEC 60559 floating-point arith-
metic’’)
tanhf(), tanhl() : ISO/IEC C99 (including Annex F, ‘‘IEC 60559 floating-point arithmetic’’)
HP-UX 11i Version 2: September 2004 − 1 − Hewlett-Packard Company Section 3−−1101