# SQL ACOS Function

The SQL ACOS function calculate the trigonometry Arc cosine for the specified expression. SQL Arc cosine also called the inverse of a COSINE Function.The syntax of the SQL Server ACOS Function is

```SELECT ACOS (Float_Expression)
FROM [Source]```

TIP: The ACOS function only accepts float values between -1 and 1. For this ACOS Function demo, we use the Math Table data

## SQL ACOS Function Example 1

The ACOS Function is used to calculate the Arc cosine for the given angle. The following SQL Server query will show you multiple ways to use the Arc COSINE function.

```DECLARE @i float
SET @i = -0.80

SELECT ACOS(@i) AS [Arc Cosine]

-- Calculating ACOS directly
SELECT ACOS(0.27) AS [Arc Cosine]

-- Calculating ACOS directly
SELECT ACOS(0.25 + 0.55 - 0.77) AS [Arc Cosine]
```

We used the ACOS function to calculate the Arccosine value for the variable @i. It means ACOS(-0.80)), and assigned a new name ‘Arc Cosine’ using ALIAS.

`SELECT ACOS(@i) AS [Arc Cosine]`

## SQL Arc Cosine Function Example 2

We calculate the Arc cosine value for all the records present in [Service Grade] using the ACOS Mathematical Function.

```SELECT [EnglishProductName]
,[Color]
,[StandardCost]
,[SalesAmount]