# Ruby – Find Inverse Arc Sine – asin() Method – Examples & Explanation

`asin()` method can be used to find the inverse arc sine of the any given complex number in Ruby programming language. `CMath.asin()` method exists in `CMath` library of Ruby language.

## `asin()` Method in Ruby

`asin()` method exists in Standard CMath Library of Ruby. The purpose of this method is to provide perfect arc sine of the given complex number.

## Syntax of the `asin()` Method in Ruby

Syntax of `asin()` Method is:

```cmath.asin(x)
```

## Parameters of `asin()` Method in Ruby

 Parameter Description `x` Any valid complex number. This parameter is required.

Note: If the `x` parameter is not a complex number, `asin()` method will return an `error`.

## Return Value of `asin()`

`asin()` method will return the arc sine of the given numeric complex number.

## Ruby – Get the `asin()` of any Given Numbers

``` # import CMath library
require 'cmath'
x = CMath.asin(5 + 5i)
puts x
```

Output

` 0.7803985799853912+2.649196177806475i`

## Ruby `asin()` Function Example 2

``` # import CMath library
require 'cmath'
x = CMath.asin(-5 + 5i)
puts x
```

Ouput

` -0.7803985799853912+2.649196177806475i`

## Ruby Non-Complex numbers in `asin()`Function Example 3

``` # import CMath library
require 'cmath'
x = CMath.asin(a5 - b5i)
puts x
```

Output

` Error`

## Ruby – Use of Negative Value in `asin()` Function Example 4

``` # import CMath library
require 'cmath'
x = CMath.asin(-5 - 5i)
puts x
```

Output

` -0.7803985799853841-2.649196177806471i`

## Ruby – Get the `asin()` of Particular Number Example 5

``` # import CMath library
require 'cmath'
x = CMath.asin(8)
puts x
```

Output

` 1.5707963267948966-2.7686593833135738i`