SQL Server ACOS() Function

Return the arc cosine of a number:

SELECT ACOS(0.25);

Definition and Usage

The ACOS() function returns the arc cosine of a number.

The specified number must be between -1 to 1, otherwise this function returns NULL.

ACOS(number)

Parameter	Description
number	Required. A numeric value

Works in:	SQL Server (starting with 2008), Azure SQL Database, Azure SQL Data Warehouse, Parallel Data Warehouse

Return the arc cosine of a number:

SELECT ACOS(-0.8);