ACOS

Return the arccosine of a number in radians (0..PI).

value = ACOS(number)

ACS is a synonym. OPTION ANGLE DEGREES makes the result degrees. See also ASIN, ATN.

Example:

PRINT ACOS(0)       ' PI/2

Source: docs/help/acos.txt inmmcore. On the computer, typeHELP ACOS.