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

NAME
       tanh, tanhf, tanhl - hyperbolic tangent function

SYNOPSIS
       #include 

       double tanh(double x);
       float tanhf(float x);
       long double tanhl(long double x);

       Link with -lm.

   Feature Test Macro Requirements for glibc (see featuretestmacros(7)):

       tanhf(), tanhl():
           BSDSOURCE || SVIDSOURCE || XOPENSOURCE >= 600 ||
           ISOC99SOURCE || POSIXCSOURCE >= 200112L;
           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.

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.  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 3.53 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/.



                                  2010-09-20                           TANH(3)