1ACOSH(3P) POSIX Programmer's Manual ACOSH(3P)
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6 This manual page is part of the POSIX Programmer's Manual. The Linux
7 implementation of this interface may differ (consult the corresponding
8 Linux manual page for details of Linux behavior), or the interface may
9 not be implemented on Linux.
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13 acosh, acoshf, acoshl — inverse hyperbolic cosine functions
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16 #include <math.h>
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18 double acosh(double x);
19 float acoshf(float x);
20 long double acoshl(long double x);
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23 The functionality described on this reference page is aligned with the
24 ISO C standard. Any conflict between the requirements described here
25 and the ISO C standard is unintentional. This volume of POSIX.1‐2008
26 defers to the ISO C standard.
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28 These functions shall compute the inverse hyperbolic cosine of their
29 argument x.
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31 An application wishing to check for error situations should set errno
32 to zero and call feclearexcept(FE_ALL_EXCEPT) before calling these
33 functions. On return, if errno is non-zero or fetestexcept(FE_INVALID |
34 FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is non-zero, an error has
35 occurred.
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38 Upon successful completion, these functions shall return the inverse
39 hyperbolic cosine of their argument.
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41 For finite values of x < 1, a domain error shall occur, and either a
42 NaN (if supported), or an implementation-defined value shall be
43 returned.
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45 If x is NaN, a NaN shall be returned.
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47 If x is +1, +0 shall be returned.
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49 If x is +Inf, +Inf shall be returned.
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51 If x is −Inf, a domain error shall occur, and a NaN shall be returned.
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54 These functions shall fail if:
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56 Domain Error
57 The x argument is finite and less than +1.0, or is −Inf.
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59 If the integer expression (math_errhandling & MATH_ERRNO)
60 is non-zero, then errno shall be set to [EDOM]. If the
61 integer expression (math_errhandling & MATH_ERREXCEPT) is
62 non-zero, then the invalid floating-point exception shall
63 be raised.
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65 The following sections are informative.
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68 None.
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71 On error, the expressions (math_errhandling & MATH_ERRNO) and
72 (math_errhandling & MATH_ERREXCEPT) are independent of each other, but
73 at least one of them must be non-zero.
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76 None.
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79 None.
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82 cosh(), feclearexcept(), fetestexcept()
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84 The Base Definitions volume of POSIX.1‐2008, Section 4.19, Treatment of
85 Error Conditions for Mathematical Functions, <math.h>
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88 Portions of this text are reprinted and reproduced in electronic form
89 from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
90 -- Portable Operating System Interface (POSIX), The Open Group Base
91 Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
92 cal and Electronics Engineers, Inc and The Open Group. (This is
93 POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the
94 event of any discrepancy between this version and the original IEEE and
95 The Open Group Standard, the original IEEE and The Open Group Standard
96 is the referee document. The original Standard can be obtained online
97 at http://www.unix.org/online.html .
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99 Any typographical or formatting errors that appear in this page are
100 most likely to have been introduced during the conversion of the source
101 files to man page format. To report such errors, see https://www.ker‐
102 nel.org/doc/man-pages/reporting_bugs.html .
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106IEEE/The Open Group 2013 ACOSH(3P)