cos() Could use an real world example of why it's desirable to use

### MDN URL

https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values/cos

### What specific section or headline is this issue about?

Introduction

### What information was incorrect, unhelpful, or incomplete?

I'm not familiar with this type of math though it appears as though one can move one thing relative to another.

It would be helpful to describe this with a desirable example of how the cos() function is useful.

### What did you expect to see?

An explanation of why the cos() function is useful in a real world scenario.

### Do you have any supporting links, references, or citations?

_No response_

### Do you have anything more you want to share?

Not high priority, but some of us going through learning about new (or not so new) things and I have no idea when or if I'd ever need this.

### MDN metadata

Page report details

* Folder: `en-us/web/css/reference/values/cos`
* MDN URL: https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values/cos
* GitHub URL: https://github.com/mdn/content/blob/main/files/en-us/web/css/reference/values/cos/index.md
* Last commit: https://github.com/mdn/content/commit/33094d735e90b4dcae5733331b79c51fee997410
* Document last modified: 2025-12-16T15:14:26.000Z