# CoffeeScript Math - atan2()

## Description

The atan2() method accepts two numbers and returns the arctangent value in radians. This method returns a numeric value between -pi and pi representing the angle theta of an (x, y) point.

## Syntax

Given below is the syntax of atan2() method of JavaScript. We can use the same method in the CoffeeScript code.

```Math.atan( x )
```

## Example

The following example demonstrates the usage of the atan2() method in CoffeeScript. Save this code in a file with name math_atan2.coffee.

```value = Math.atan2 90,15
console.log "The arc tangent value of 90,15 is : " + value

value = Math.atan2 15,90
console.log "The arc tangent value of 15,90 is : " + value

value = Math.atan2 0,-0
console.log "The arc tangent value of 0,-0 is : " + value

value = Math.atan2 +Infinity, -Infinity
console.log "The arc tangent value of +Infinity, -Infinity is : " + value
```

Open the command prompt and compile the .coffee file as shown below.

```c:\> coffee -c math_atan2.coffee
```

On compiling, it gives you the following JavaScript.

```// Generated by CoffeeScript 1.10.0
(function() {
var value;

value = Math.atan(-1);

console.log("The arc tangent value of -1 is : " + value);

value = Math.atan(null);

console.log("The arc tangent value of null is : " + value);

value = Math.atan(20);

console.log("The arc tangent value of 20 is : " + value);

}).call(this);
```

Now, open the command prompt again, and run the CoffeeScript file as shown below.

```c:\> coffee math_atan2.coffee
```

On executing, the CoffeeScript file produces the following output.

```The arc tangent value of 90,15 is : 1.4056476493802699
The arc tangent value of 15,90 is : 0.16514867741462683
The arc tangent value of 0,-0 is : 3.141592653589793
The arc tangent value of +Infinity, -Infinity is : 2.356194490192345
```
coffeescript_math.htm