acos(3)

NAME

acos, acosf, acosl — arc cosine functions

SYNOPSIS

/* -lm */
#include <math.h>

double
acos(double x);

float
acosf(float x);

long double
acosl(long double x);

DESCRIPTION

The acos() function computes the principal value of the arc cosine of x in the range [0, pi]. The acosf() function is a single precision version of acos(). The acosl() function is an extended precision version of acos().

RETURN VALUES

If |x|>1, acos(x), acosf(x) and acosl(x) set the global variable errno to EDOM.

SEE ALSO

asin(3), atan(3), atan2(3), cos(3), cosh(3), sin(3), sinh(3), tan(3), tanh(3)