ATAN (Transact-SQL)

Applies to: 👁 Image
SQL Server 👁 Image
Azure SQL Database 👁 Image
Azure SQL Managed Instance 👁 Image
Azure Synapse Analytics 👁 Image
Analytics Platform System (PDW) 👁 Image
SQL analytics endpoint in Microsoft Fabric 👁 Image
Warehouse in Microsoft Fabric 👁 Image
SQL database in Microsoft Fabric

A function that returns the angle, in radians, whose tangent is a specified float expression. This is also called arctangent.

👁 Image
Transact-SQL syntax conventions

Syntax

ATAN ( float_expression ) 

Arguments

float_expression
An expression of either type float or of a type that implicitly convert to float.

Return types

float

Examples

This example takes a float expression and returns the ATAN of the specified angle.

SELECT 'The ATAN of -45.01 is: ' + CONVERT(varchar, ATAN(-45.01)) 
SELECT 'The ATAN of -181.01 is: ' + CONVERT(varchar, ATAN(-181.01)) 
SELECT 'The ATAN of 0 is: ' + CONVERT(varchar, ATAN(0)) 
SELECT 'The ATAN of 0.1472738 is: ' + CONVERT(varchar, ATAN(0.1472738)) 
SELECT 'The ATAN of 197.1099392 is: ' + CONVERT(varchar, ATAN(197.1099392)) 
GO 

Here's the result set.

 
------------------------------- 
The ATAN of -45.01 is: -1.54858 
 
(1 row(s) affected) 
 
-------------------------------- 
The ATAN of -181.01 is: -1.56527 
 
(1 row(s) affected) 
 
-------------------------------- 
The ATAN of 0 is: 0 
 
(1 row(s) affected) 
 
---------------------------------- 
The ATAN of 0.1472738 is: 0.146223 
 
(1 row(s) affected) 
 
----------------------------------- 
The ATAN of 197.1099392 is: 1.56572 
 
(1 row(s) affected) 

Examples: Azure Synapse Analytics and Analytics Platform System (PDW)

This example takes a float expression and returns the arctangent of the specified angle.

SELECT ATAN(45.87) AS atanCalc1, 
 ATAN(-181.01) AS atanCalc2, 
 ATAN(0) AS atanCalc3, 
 ATAN(0.1472738) AS atanCalc4, 
 ATAN(197.1099392) AS atanCalc5; 

Here's the result set.

atanCalc1 atanCalc2 atanCalc3 atanCalc4 atanCalc5
--------- --------- --------- --------- ---------
1.55 -1.57 0.00 0.15 1.57

See also

CEILING (Transact-SQL)
Mathematical Functions (Transact-SQL)