cosh.3p (3577B)
- '\" et
- .TH COSH "3P" 2017 "IEEE/The Open Group" "POSIX Programmer's Manual"
- .\"
- .SH PROLOG
- This manual page is part of the POSIX Programmer's Manual.
- The Linux implementation of this interface may differ (consult
- the corresponding Linux manual page for details of Linux behavior),
- or the interface may not be implemented on Linux.
- .\"
- .SH NAME
- cosh,
- coshf,
- coshl
- \(em hyperbolic cosine functions
- .SH SYNOPSIS
- .LP
- .nf
- #include <math.h>
- .P
- double cosh(double \fIx\fP);
- float coshf(float \fIx\fP);
- long double coshl(long double \fIx\fP);
- .fi
- .SH DESCRIPTION
- The functionality described on this reference page is aligned with the
- ISO\ C standard. Any conflict between the requirements described here and the
- ISO\ C standard is unintentional. This volume of POSIX.1\(hy2017 defers to the ISO\ C standard.
- .P
- These functions shall compute the hyperbolic cosine of their argument
- .IR x .
- .P
- An application wishing to check for error situations should set
- .IR errno
- to zero and call
- .IR feclearexcept (FE_ALL_EXCEPT)
- before calling these functions. On return, if
- .IR errno
- is non-zero or \fIfetestexcept\fR(FE_INVALID | FE_DIVBYZERO |
- FE_OVERFLOW | FE_UNDERFLOW) is non-zero, an error has occurred.
- .SH "RETURN VALUE"
- Upon successful completion, these functions shall return the hyperbolic
- cosine of
- .IR x .
- .P
- If the correct value would cause overflow, a range error shall occur
- and
- \fIcosh\fR(),
- \fIcoshf\fR(),
- and
- \fIcoshl\fR()
- shall return the value of the macro HUGE_VAL, HUGE_VALF, and HUGE_VALL,
- respectively.
- .P
- If
- .IR x
- is NaN, a NaN shall be returned.
- .P
- If
- .IR x
- is \(+-0, the value 1.0 shall be returned.
- .P
- If
- .IR x
- is \(+-Inf, +Inf shall be returned.
- .SH ERRORS
- These functions shall fail if:
- .IP "Range\ Error" 12
- The result would cause an overflow.
- .RS 12
- .P
- If the integer expression (\fImath_errhandling\fR & MATH_ERRNO) is
- non-zero, then
- .IR errno
- shall be set to
- .BR [ERANGE] .
- If the integer expression (\fImath_errhandling\fR & MATH_ERREXCEPT) is
- non-zero, then the overflow floating-point exception shall be raised.
- .RE
- .LP
- .IR "The following sections are informative."
- .SH EXAMPLES
- None.
- .SH "APPLICATION USAGE"
- On error, the expressions (\fImath_errhandling\fR & MATH_ERRNO) and
- (\fImath_errhandling\fR & MATH_ERREXCEPT) are independent of each
- other, but at least one of them must be non-zero.
- .SH RATIONALE
- None.
- .SH "FUTURE DIRECTIONS"
- None.
- .SH "SEE ALSO"
- .IR "\fIacosh\fR\^(\|)",
- .IR "\fIfeclearexcept\fR\^(\|)",
- .IR "\fIfetestexcept\fR\^(\|)",
- .IR "\fIisnan\fR\^(\|)",
- .IR "\fIsinh\fR\^(\|)",
- .IR "\fItanh\fR\^(\|)"
- .P
- The Base Definitions volume of POSIX.1\(hy2017,
- .IR "Section 4.20" ", " "Treatment of Error Conditions for Mathematical Functions",
- .IR "\fB<math.h>\fP"
- .\"
- .SH COPYRIGHT
- Portions of this text are reprinted and reproduced in electronic form
- from IEEE Std 1003.1-2017, Standard for Information Technology
- -- Portable Operating System Interface (POSIX), The Open Group Base
- Specifications Issue 7, 2018 Edition,
- Copyright (C) 2018 by the Institute of
- Electrical and Electronics Engineers, Inc and The Open Group.
- In the event of any discrepancy between this version and the original IEEE and
- The Open Group Standard, the original IEEE and The Open Group Standard
- is the referee document. The original Standard can be obtained online at
- http://www.opengroup.org/unix/online.html .
- .PP
- Any typographical or formatting errors that appear
- in this page are most likely
- to have been introduced during the conversion of the source files to
- man page format. To report such errors, see
- https://www.kernel.org/doc/man-pages/reporting_bugs.html .