1TANH(3)                    Linux Programmer's Manual                   TANH(3)
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NAME

6       tanh, tanhf, tanhl - hyperbolic tangent function
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SYNOPSIS

9       #include <math.h>
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11       double tanh(double x);
12       float tanhf(float x);
13       long double tanhl(long double x);
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15       Link with -lm.
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17   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
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19       tanhf(), tanhl(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600
20       || _ISOC99_SOURCE; or cc -std=c99
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DESCRIPTION

23       The tanh() function returns the  hyperbolic  tangent  of  x,  which  is
24       defined mathematically as:
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26           tanh(x) = sinh(x) / cosh(x)
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RETURN VALUE

29       On success, these functions return the hyperbolic tangent of x.
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31       If x is a NaN, a NaN is returned.
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33       If x is +0 (-0), +0 (-0) is returned.
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35       If x is positive infinity (negative infinity), +1 (-1) is returned.
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ERRORS

38       No errors occur.
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CONFORMING TO

41       C99, POSIX.1-2001.  The variant returning double also conforms to SVr4,
42       4.3BSD, C89.
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SEE ALSO

45       acosh(3), asinh(3), atanh(3), cosh(3), ctanh(3), sinh(3)
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COLOPHON

48       This page is part of release 3.22 of the Linux  man-pages  project.   A
49       description  of  the project, and information about reporting bugs, can
50       be found at http://www.kernel.org/doc/man-pages/.
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54                                  2008-08-05                           TANH(3)
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