Calculates the arc cosine of a floating-point number.

[Format]

#include <mathf.h>

float acosf (float f);

[Parameters]

f Floating-point number for which arc cosine is to be computed

[Return values]

Normal: Arc cosine of f

Abnormal: Domain error: Returns not-a-number.

[Remarks]

A domain error occurs for a value of f not in the range [–1.0, +1.0]

The acosf function returns the arc cosine in the range [0, π] by the radian.