ATAN (Transact-SQL)

**APPLIES TO:** ![yes](media/yes.png)SQL Server (starting with 2008) ![yes](media/yes.png)Azure SQL Database ![yes](media/yes.png)Azure SQL Data Warehouse ![yes](media/yes.png)Parallel Data Warehouse

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

Topic link icon 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 is 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: [!INCLUDEssSDWfull] and [!INCLUDEssPDW]

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;