---
title: "ATN2 (Transact-SQL) | Microsoft Docs"
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  - "ATN2 function"
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---
# ATN2 (Transact-SQL)
[!INCLUDE[tsql-appliesto-ss2008-all_md](../../includes/tsql-appliesto-ss2008-all-md.md)]

Returns the angle, in radians, between the positive x-axis and the ray from the origin to the point (y, x), where x and y are the values of the two specified float expressions.
  
![Topic link icon](../../database-engine/configure-windows/media/topic-link.gif "Topic link icon") [Transact-SQL Syntax Conventions](../../t-sql/language-elements/transact-sql-syntax-conventions-transact-sql.md)
  
## Syntax  
  
```sql
-- Syntax for SQL Server, Azure SQL Database, Azure SQL Data Warehouse, Parallel Data Warehouse  
  
ATN2 ( float_expression , float_expression )  
```  
  
## Arguments  
*float_expression*
Is an [expression](../../t-sql/language-elements/expressions-transact-sql.md) of the **float** data type.
  
## Return types
**float**
  
## Examples  
The following example calculates the `ATN2` for the specified `x` and `y` components.
  
```sql
DECLARE @x float = 35.175643, @y float = 129.44;  
SELECT 'The ATN2 of the angle is: ' + CONVERT(varchar,ATN2(@x,@y ));  
GO  
```  
  
[!INCLUDE[ssResult](../../includes/ssresult-md.md)]
  
```sql
The ATN2 of the angle is: 0.265345                         
(1 row(s) affected)  
```  
  
## Examples:
 [!INCLUDE[ssSDWfull](../../includes/sssdwfull-md.md)] and [!INCLUDE[ssPDW](../../includes/sspdw-md.md)] 

The following example calculates the `ATN2` for the specified `x` and `y` components.
  
```sql
DECLARE @x float = 35.175643, @y float = 129.44;  
SELECT 'The ATN2 of the angle is: ' + CONVERT(varchar,ATN2(@x,@y ));  
GO  
```  
  
[!INCLUDE[ssResult](../../includes/ssresult-md.md)]
  
```sql
The ATN2 of the angle is: 0.265345                         
(1 row(s) affected)  
```  
  
## See also
[CAST and CONVERT (Transact-SQL)](../../t-sql/functions/cast-and-convert-transact-sql.md)  
[float and real (Transact-SQL)](../../t-sql/data-types/float-and-real-transact-sql.md)  
[Mathematical Functions (Transact-SQL)](../../t-sql/functions/mathematical-functions-transact-sql.md)