The **`Atan`** function in the Go programming language is used to find the arc tangent value of the angle passed to it as input.

To use the `Atan` function, you must import the `math` package in your file and access the `Atan` function within it using the `.` notation (`math.Atan`). Here, `Atan` is the actual function, while `math` is the Go package that stores the definition of this function.

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## Syntax

The definition of the `Atan` function inside the `math` package is shown below:

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## Parameters

The `Atan` function takes a single argument of type `float64` that represents the angle whose arc tangent value you want to find.



## Return value
The `Atan` function returns a single value of type `float64` that represents the arc tangent value of the argument. The possible range of all return values is between *-π/2* to *π/2* radians.

> An exception to the above statements is when you pass something as an argument that is `NAN`. In these cases, the `Atan` function returns `NAN`.





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## Examples

Below is a simple example in which we use the `Atan` function to find the arc tangent value of 25:

package main

import "fmt"
import  "math"


func main() {
	
	x := math.Atan(25)
	fmt.Println(x)
} 

The following example shows how passing `NAN` as an argument makes the `Atan` function return `NAN`:


package main

import "fmt"
import  "math"

func main() {
	
	x := math.Atan(math.NaN())
	fmt.Println(x)
} 

What is the Atan function in Golang?

The Atan function in Go returns the arc tangent of a given float64 input, ranging from -π/2 to π/2.