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

6       cosh, coshf, coshl - hyperbolic cosine function
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SYNOPSIS

9       #include <math.h>
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11       double cosh(double x);
12       float coshf(float x);
13       long double coshl(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       coshf(), coshl(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600
20       || _ISOC99_SOURCE; or cc -std=c99
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DESCRIPTION

23       The cosh() function returns  the  hyperbolic  cosine  of  x,  which  is
24       defined mathematically as:
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26           cosh(x) = (exp(x) + exp(-x)) / 2
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RETURN VALUE

29       On success, these functions return the hyperbolic cosine 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 or -0, 1 is returned.
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35       If  x  is  positive infinity or negative infinity, positive infinity is
36       returned.
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38       If the result overflows, a range error occurs, and the functions return
39       +HUGE_VAL, +HUGE_VALF, or +HUGE_VALL, respectively.
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ERRORS

42       See  math_error(7) for information on how to determine whether an error
43       has occurred when calling these functions.
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45       The following errors can occur:
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47       Range error: result overflow
48              errno is set to ERANGE.  An  overflow  floating-point  exception
49              (FE_OVERFLOW) is raised.
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CONFORMING TO

52       C99, POSIX.1-2001.  The variant returning double also conforms to SVr4,
53       4.3BSD.
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BUGS

56       In  glibc  version  2.3.4  and  earlier,  an  overflow   floating-point
57       (FE_OVERFLOW) exception is not raised when an overflow occurs.
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SEE ALSO

60       acosh(3), asinh(3), atanh(3), ccos(3), sinh(3), tanh(3)
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COLOPHON

63       This  page  is  part of release 3.25 of the Linux man-pages project.  A
64       description of the project, and information about reporting  bugs,  can
65       be found at http://www.kernel.org/doc/man-pages/.
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69                                  2008-08-10                           COSH(3)
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