# CoffeeScript Math - asin()

## Description

The asin() method accepts an integer value and returns its arc-sine in radians. The asin method returns a numerical value between -pi/2 and pi/2 radians for x between -1 and 1. If the value of number is outside this range, it returns NaN.

## Syntax

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

```Math.asin( x )
```

## Example

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

```value = Math.asin -1
console.log "The arc sine value of -1 is : " + value

value = Math.asin null
console.log "The arc sine value of null is : " + value

value = Math.asin 20
console.log "The arc sine value of 20 is : " + value
```

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

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

On compiling, it gives you the following JavaScript.

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

value = Math.asin(-1);

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

value = Math.asin(null);

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

value = Math.asin(20);

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

}).call(this);
```

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

```c:\> coffee math_asin.coffee
```

On executing, the CoffeeScript file produces the following output.

```The arc sine value of -1 is : -1.5707963267948966
The arc sine value of null is : 0
The arc sine value of 20 is : NaN
```
coffeescript_math.htm