ACOS(3) NEWLIB ACOS(3)NAME
1.3 `acos', `acosf'--arc cosine
SYNOPSIS
#include <math.h>
double acos(double X);
float acosf(float X);
DESCRIPTION
`acos' computes the inverse cosine (arc cosine) of the input value.
Arguments to `acos' must be in the range -1 to 1.
`acosf' is identical to `acos', except that it performs its calcula‐
tions on `floats'.
RETURNS
`acos' and `acosf' return values in radians, in the range of 0 to pi.
If X is not between -1 and 1, the returned value is NaN (not a number)
the global variable `errno' is set to `EDOM', and a `DOMAIN error' mes‐
sage is sent as standard error output.
You can modify error handling for these functions using `matherr'.
SEE ALSOacos is part of the library. The full documentation for is maintained
as a Texinfo manual. If info and are properly installed at your site,
the command
info
will give you access to the complete manual.
NEWLIB April 2010 ACOS(3)
