SQL Server ATAN() Function

Return the arc tangent of a number:

SELECT ATAN(2.5);

Definition and Usage

The ATAN() function returns the arc tangent of a number.

ATAN(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 tangent of a number:

SELECT ATAN(-45.01);