NAME
tanh,
tanhf —
hyperbolic tangent function
LIBRARY
Math Library (libm, -lm)
SYNOPSIS
#include <math.h>
double
tanh(
double
x);
float
tanhf(
float
x);
DESCRIPTION
The
tanh() and
tanhf() functions compute the
hyperbolic tangent of
x. For a discussion of error due
to roundoff, see
math(3).
RETURN VALUES
Upon successful completion, these functions return the hyperbolic tangent value.
The following may also occur:
- If x is ± 0,
x is returned.
- If x is NaN, a NaN is returned.
- If x is positive infinity, a value 1
is returned; if x is negative infinity, -1 is
returned.
- If x is subnormal, a range error can
occur and x is returned.
SEE ALSO
acos(3),
asin(3),
atan(3),
atan2(3),
cos(3),
cosh(3),
math(3),
sin(3),
sinh(3),
tan(3)
STANDARDS
The described functions conform to
ISO/IEC 9899:1999
(“ISO C99”).