The **`Atan2`** function in the Go programming language is used to find the arc tangent value of the $x/y$ value, where $x$ and $y$ are the two parameters.

To use the `Atan2` function, you must import the `math` package in your file and access the `Atan2` function within it using the `.` notation (`math.Atan2`). Here, `Atan2` is the actual function, while `math` is the Go package that stores the definition of this function.

#      
## Syntax

The definition of the `Atan2` function inside the `math` package is shown below:

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## Parameters

The `Atan2` function takes two arguments of type `float64`. The ratio of these two arguments ($y/x$) is then used to calculate the value of the arc tangent.



## Return value
The `Atan2` function returns a single value of type `float64` that represents the arc tangent value of the ratio of the arguments ($y/x$). The possible range of all return values is between *-π* to *π* radians.

Below is a list of special cases in the return values:

* `NAN`:
  * Atan2(y, NaN) = NaN
  * Atan2(NaN, x) = NaN

* `(+-)0`:
   * Atan2(+0, x>=0) = +0
   * Atan2(-0, x>=0) = -0
   * Atan2(y, +Inf) = +0

* `(+-)π`:
   * Atan2(+0, x<=-0) = +π
   * Atan2(-0, x<=-0) = -π 
   * Atan2(y>0, -Inf) = +π
   * Atan2(y<0, -Inf) = -π
     

* `(+-)π/2`:
   * Atan2(y>0, 0) = +π/2
   * Atan2(y<0, 0) = -π/2 
   * Atan2(+Inf, x) = +π/2
   * Atan2(-Inf, x) = -π/2

* `(+-)π/4`:
   * Atan2(+Inf, +Inf) = +π/4        
   * Atan2(-Inf, +Inf) = -π/4 


* `(+-)3π/4`:
    * Atan2(+Inf, -Inf) = 3π/4 
   * Atan2(-Inf, -Inf) = -3π/4 













#     
## Examples

Below is a simple example in which we use the `Atan2` function to find the arc tangent value with the parameters -25 and 25:

package main

import "fmt"
import  "math"


func main() {
	
	x := math.Atan2(-25, 25)
	fmt.Println(x)
} 

The following example shows that `NAN` is returned whenever there is `NAN` in any of the  arguments:

package main

import "fmt"
import  "math"


func main() {
	
	x := math.Atan2(math.NaN(), 25)
	fmt.Println(x)
	
	y := math.Atan2(25, math.NaN())
	fmt.Println(y)
} 

What is the Atan2 function in Golang?

The Atan2 function in the Go programming language is used to find the arc tangent value of the x/yx/yx/y value, where xxx and yyy are the two parameters. To use the Atan2 function, you must import the math package in your file and access the Atan2 function within it using the . notation (math.Atan2). Here, Atan2 is the actual function, while math is the Go package that stores the definition of this function.  Syntax The definition of the Atan2 function inside the math package is shown below: 