ACOS(3)

NAME
acos - arc cosine function

SYNOPSIS
#include <math.h>
double
acos(double x);
float
acosf(float x);

DESCRIPTION
The acos() and acosf() functions compute the principal value of the arc cosine of x in the range [0,].

RETURN VALUES
Exceptional cases are handled by matherr(3).

SEE ALSO
sin(3), cos(3), tan(3), asin(3), atan(3), atan2(3), sinh(3), cosh(3), tanh(3), math(3), matherr(3)