# COS: The Cornerstone of Triangles

Need to find the cosine of an angle? Look no further than the `COS`

command, your trusty trigonometry companion! This essential function takes an angle (in radians) and returns its cosine value, a key ingredient in understanding triangles and all sorts of geometric and mathematical wonders.

### Syntax

```
COS(<angle>)
```

Where:
- `<angle>`

: The angle (in radians) for which you want to find the cosine.

### Applications

The `COS`

command is your go-to tool when:

- You're working with right triangles and need to find the ratio of the adjacent side to the hypotenuse.
- You're dealing with waves, oscillations, or circular motion, where cosine functions play a crucial role.
- You're creating games or simulations that involve trigonometry for calculating positions or trajectories.

### Code Examples

**1. Simple Cosine Calculation:**

```
10 PI=3.141592653
20 R=PI/3 :rem Angle of 60 degrees in radians (PI is a system variable)
30 C=COS(R) :rem C stores the cosine of the angle
40 PRINT C :rem Output: 0.5
```

This example demonstrates how to find the cosine of 60 degrees (which is 0.5).

**2. Finding Horizontal Displacement:**

```
10 PI=3.141592653
20 INPUT "Enter angle (degrees): "; A
30 INPUT "Enter hypotenuse: "; H
40 R=A*PI/180 :rem Convert angle to radians
50 X=H*COS(R) :rem Calculate horizontal displacement
60 PRINT "Horizontal displacement: "; X
```

Here, `COS`

helps calculate the horizontal component of a vector given its angle and magnitude (hypotenuse).

### COS in the Wild: The Rhythm of the Universe

The cosine function is everywhere in nature! From the swinging of a pendulum to the orbits of planets, `COS`

is the mathematical language that describes these rhythmic patterns. Even the alternating current in your Commodore 64 follows a cosine wave!

Don't let triangles be a mystery! With `COS`

in your programming arsenal, you can unlock the secrets of angles and ratios, opening up a world of possibilities in geometry, physics, and beyond. So go ahead and embrace the cosine – it's the key to understanding the harmony of shapes and motion!