acos-transact-sql.md

title	ACOS (Transact-SQL)
description	ACOS (Transact-SQL)
author	markingmyname
ms.author	maghan
ms.date	07/24/2017
ms.service	sql
ms.subservice	t-sql
ms.topic	reference
ms.custom	ignite-2025
f1_keywords	ACOS ACOS_TSQL
helpviewer_keywords	cosine ACOS function arccosine
dev_langs	TSQL
monikerRange	>=aps-pdw-2016 || =azuresqldb-current || =azure-sqldw-latest || >=sql-server-2016 || >=sql-server-linux-2017 || =azuresqldb-mi-current || =fabric || =fabric-sqldb

ACOS (Transact-SQL)

[!INCLUDE sql-asdb-asdbmi-asa-pdw-fabricse-fabricdw-fabricsqldb]

A function that returns the angle, in radians, whose cosine is the specified float expression. This is also called arccosine.

:::image type="icon" source="../../includes/media/topic-link-icon.svg" border="false"::: Transact-SQL syntax conventions

Syntax

ACOS ( float_expression )  

Arguments

float_expression
An expression of either type float or of a type that can implicitly convert to float. Only a value ranging from -1.00 to 1.00 is valid. For values outside this range, no value is returned, and ACOS will report a domain error.

Return types

float

Examples

This example returns the ACOS value of the specified number.

SET NOCOUNT OFF;  
DECLARE @cos FLOAT;  
SET @cos = -1.0;  
SELECT 'The ACOS of the number is: ' + CONVERT(VARCHAR, ACOS(@cos));  

[!INCLUDEssResult]

---------------------------------   
The ACOS of the number is: 3.14159   
  
(1 row(s) affected)  

See also

Mathematical Functions (Transact-SQL)
Functions