From AutoIt Wiki

ACos calculates the arcCosine of a number. Adapted from AutoIt doc.

Contents 1 Syntax 2 Parameters 3 Return Value 4 Example

[edit] Syntax

$x = ACos(expr)

[edit] Parameters

Param	Purpose
expr	Value to be calculated ranging from -1 to 1

[edit] Return Value

Returns the trigonometric arccosine of expression. Result is returned in radians.

[edit] Example

$x = ACos(0.5)
$pi = 3.14159265358979
$radToDeg = 180 / $pi
$y = ACos(-1) * $radToDeg   ; arcCos of -1 = 180 deg