ACOS(3) BSD Library Functions Manual ACOS(3)NAME
acos, acosf, acosl — arc cosine functions
LIBRARY
Math Library (libm, -lm)
SYNOPSIS
#include <math.h>
double
acos(double x);
float
acosf(float x);
long double
acosl(long double x);
DESCRIPTION
The acos(), acosf(), and acosl() functions compute the principal value of
the arc cosine of x.
RETURN VALUES
These functions return the arc cosine in the range [0, π] radians. If:
|x| > 1,
acos(x) raises an invalid exception and returns an NaN.
SEE ALSOasin(3), atan(3), atan2(3), cos(3), cosh(3), fenv(3), math(3), sin(3),
sinh(3), tan(3), tanh(3)STANDARDS
The acos(), acosf(), and acosl() functions conform to ISO/IEC 9899:1999
(“ISO C99”).
BSD July 31, 2008 BSD