# Cos

The cosine function

`fun cos(radians)`

```
```

## Parameters

- radians: The angle of the function

## Discussion

The argument of `cos`

is assumed to be in radians. To use degrees or another unit, you can specify it with the value:

```
cos(0)
cos(pi/2)
cos(180 degrees)
```

```
1
0
-1
```

`cos`

is valid for all finite numbers