Linux and UNIX Man Pages

Test Your Knowledge in Computers #614
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In Python, strings in double quotes work exactly the same way as strings in single quotes.
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acoshl(3m) [opensolaris man page]

```acosh(3M)						  Mathematical Library Functions						 acosh(3M)

NAME
acosh, acoshf, acoshl - inverse hyperbolic cosine functions

SYNOPSIS
c99 [ flag... ] file... -lm [ library... ]
#include <math.h>

double acosh(double x);

float acoshf(float x);

long double acoshl(long double x);

DESCRIPTION
These functions compute the inverse hyperbolic cosine of their argument x.

RETURN VALUES
Upon successful completion, these functions return the inverse hyperbolic cosine of their argument.

For finite values of  x < 1, a domain error occurs and NaN is returned.

If x is NaN, NaN is returned.

If x is +1, +0 is returned.

If x is +Inf, +Inf is returned.

If x is -Inf, a domain error occurs and NaN is returned.

For exceptional cases, matherr(3M) tabulates the values to be returned by acosh() as specified by SVID3 and XPG3.

ERRORS
These functions will fail if:

Domain Error    The x argument is finite and less than 1.0, or is -Inf.

If the integer expression (math_errhandling & MATH_ERREXCEPT) is non-zero, the invalid floating-point exception is raised.

The acosh() function sets errno to EDOM if x is less than 1.0.

USAGE
An  application	wanting  to  check  for  exceptions should call feclearexcept(FE_ALL_EXCEPT) before calling these functions. On return, if
fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is non-zero, an exception  has  been  raised.  An  application  should
either examine the return value or check the floating point exception flags to detect exceptions.

An  application	can  also  set errno to 0 before calling acosh(). On return, if errno is non-zero, an error has occurred. The acoshf() and
acoshl() functions do not set errno.

ATTRIBUTES
See attributes(5) for descriptions of the following attributes:

+-----------------------------+-----------------------------+
|      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
+-----------------------------+-----------------------------+
|Interface Stability	     |Standard			   |
+-----------------------------+-----------------------------+
|MT-Level		     |MT-Safe			   |
+-----------------------------+-----------------------------+