TANH(3) |
Library Functions Manual |
TANH(3) |
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.
STANDARDS
The described functions conform to ISO/IEC 9899:1999 (“ISO C99”).