Amazon Redshift will no longer support the creation of new Python UDFs starting Patch 198. Existing Python UDFs will continue to function until June 30, 2026. For more information, see the [ blog post ](https://aws.amazon.com/blogs/big-data/amazon-redshift-python-user-defined-functions-will-reach-end-of-support-after-june-30-2026/). 

# COS function
<a name="r_COS"></a>

COS is a trigonometric function that returns the cosine of a number. The return value is in radians and is between `-1` and `1`, inclusive. 

## Syntax
<a name="r_COS-synopsis"></a>

```
COS(double_precision)
```

## Arguments
<a name="r_COS-argument"></a>

 *number*   
The input parameter is a `DOUBLE PRECISION` number. 

## Return type
<a name="r_COS-return-type"></a>

The COS function returns a `DOUBLE PRECISION` number. 

## Examples
<a name="r_COS-examples"></a>

To return the cosine of `0`, use the following example. 

```
SELECT COS(0);

+-----+
| cos |
+-----+
|   1 |
+-----+
```

To return the cosine of `pi`, use the following example. 

```
SELECT COS(PI());

+-----+
| cos |
+-----+
|  -1 |
+-----+
```