From BorielWiki

[edit] ACS

Returns the arc cosine value of the given argument. Argument must be a numeric expression. Returned value type is float.

Example:

REM Arc cosine value
PRINT "Arc Cosine value of a is "; ACS(a)

[edit] Remarks

• This function is 100% Sinclair BASIC Compatible
• If the given argument type is not float, it will be converted to float before operating with it.

[edit] See Also

• SIN and ASN
• TAN and ATN
• COS