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TANH(3) Linux Programmer's Manual TANH(3)

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():
         _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
             || /* Since glibc 2.19: */ _DEFAULT_SOURCE
             || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

DESCRIPTION

     These  functions  return  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.

ATTRIBUTES

     For  an  explanation  of  the  terms  used   in   this   section,   see
     attributes(7).

     +-------------------------+---------------+---------+
     |Interface                | Attribute     | Value   |
     +-------------------------+---------------+---------+
     |tanh(), tanhf(), tanhl() | Thread safety | MT-Safe |
     +-------------------------+---------------+---------+

CONFORMING TO

     C99, POSIX.1-2001, POSIX.1-2008.

     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

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     description  of  the project, information about reporting bugs, and the
     latest    version    of    this    page,    can     be     found     at
     https://www.kernel.org/doc/man-pages/.

                                2017-09-15                           TANH(3)