Go to the first, previous, next, last section, table of contents.

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 calculations on floats.


Returns

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 message is sent as standard error output.

You can modify error handling for these functions using matherr.


Go to the first, previous, next, last section, table of contents.