---
title: cos
card_id: 54961
---

# cos

```
the cos of [ph:number]
```

Value returned: number equal to the trigonometric cosine of `[ph:number]` expressed in radians

Note: There are 2 * pi radians in 360 degrees.

## Examples

```
the cos of 0  -- returns 1
the cos of pi -- returns -1
the cos of pi / 2  -- returns -.5
the cos of (pi / 2) -- returns 0
```

## Related Topics

* [atan](/HyperTalkReference/functions/atan)
* [numberFormat](/HyperTalkReference/properties/numberFormat)
* [sin](/HyperTalkReference/functions/sin)
* [tan](/HyperTalkReference/functions/tan)