# SQL COS Function

The SQL Server COS function is a Mathematical Function that calculates the trigonometry Cosine for the specified expression. The syntax of the COS Function is shown below.

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

For this COS Function demo, we use the Math Table data

## SQL COS Function Example

The mathematical formula for this function is COS(x) = Length of the Adjacent Side / Length of the Hypotenuse. The COS Function calculates the Cosine for a given angle. The following query shows you multiple ways to use this COS function.

```DECLARE @i float
SET @i = 208.45

SELECT COS(@i)AS [SQLCosine]

-- Calculating COS directly
SELECT COS(0.24)AS [SQLCosine]

-- Calculating COS directly
SELECT COS(0)AS [SQLCosine]

-- Calculating COS directly
SELECT COS(1)AS [SQLCosine]```

We used the COS Mathematical Function to calculate the Cosine value for the variable @i. It means COS(208.45)

`SELECT COS(@i)AS [SQLCosine]`

In the next SQL Server statement, we used the Cosine Function directly on the float values.

`SELECT COS(0.24)AS [SQLCosine]`

## SQL COS Function Example 2

In this COS Function example, we are going to calculate the Cosine value for all the records present in [Tax Amount] and [Service Grade] of the Mathematical function table.

```SELECT [EnglishProductName]
,[SalesAmount]
,[TaxAmt]
,COS([TaxAmt]) AS [Tax Cosine]