SQL Server ATAN() Function

The ATAN() function in SQL Server calculates the arctangent (inverse tangent) of a number. The arctangent is the angle whose tangent is the given number. The result is expressed in radians.

ATAN(): Definition and Usage

This function is primarily used in mathematical and geometrical computations. It's the inverse of the TAN() function; given the tangent of an angle, ATAN() returns the angle itself.

Syntax

Syntax

ATAN(number)

Parameter Values

Parameter Description
number The numeric value for which you want to calculate the arctangent. This is required. The result will be in radians.

Examples

Calculating the Arctangent of a Positive Number

This example finds the arctangent of 2.5.

Syntax

SELECT ATAN(2.5);
Output

1.19028994968263 (The exact value may vary slightly depending on your SQL Server version)

Calculating the Arctangent of a Negative Number

This example shows the arctangent of -45.01.

Syntax

SELECT ATAN(-45.01);
Output

-1.55987679578246 (The exact value may vary slightly depending on your SQL Server version)

Technical Details

The ATAN() function is supported in:

  • SQL Server (starting with version 2008)
  • Azure SQL Database
  • Azure SQL Data Warehouse
  • Parallel Data Warehouse