While testing Firebird with LO 5.4.0.0 alpha0 I get the following: SELECT ACOS(1.1) FROM "Table" firebird sdbc-error ... *Argument for ACOS must be in the range [-1,1] Same in HSQLDB doesn't throw an error. Writes only down 'NaN' instead of any value. The behavior of both is correct. But wouldn't it be better Firebird ignores wrong values and gives 'NaN' as HSQLDB does?
That's a Firebird question, not LibreOffice.