---
layout: doc
title: floats / acos
---
# acos

### NAME

    acos() - return the arccosine of a float

### SYNOPSIS

    float acos( float f );

### DESCRIPTION

    Returns the arccosine of its argument, 'f', measured in radians.

### SEE ALSO

    asin(3), atan(3), cos(3), sin(3), tan(3)

