The **`tan()` function** calculates and returns the tangent of a number. To be more specific, it returns the tangent of a number in radians. 

Figure 1 shows the mathematical representation of the `tan()` function.

>Note:
>- This function is present in the `Math` module.
>- This `tan()` function only works for right-angled triangles. 


# Syntax
```ruby
tan(num)
```
# Parameter
This function requires a `number` that represents an `angle` in `radians` as a parameter.

To convert `degrees` to `radians`, use the following formula.
```ruby
radians = degrees * ( pi / 180.0 )
```

# Return value
`tan()` returns the `tangent` of a number that is set as a parameter. The return value is in the range `[-1,1]`.

# Example



#positive number in radians
puts "The value of tan(2.3) : ",  Math.tan(2.3)

#negative number in radians
puts "The value of tan(-2.3) : ",  Math.tan(-2.3)

#converting the degrees angle into radians and then applying tan()
#degrees = 45
#PI = 3.14159265
result = 45 * (Math::PI / 180.0)
puts "The value of tan(#{result}) : ",  Math.tan(result)

What is Math.tan() in Ruby?

The tan() function in Ruby's Math module calculates the tangent of a number in radians.