 # JavaScript Math atan2()

In this tutorial, you will learn about the JavaScript Math.atan2() method with the help of examples.

The `atan2()` method divides its two arguments and computes the arctan (inverse of tangent) of the result.

### Example

``````let num = Math.atan2(4, 3);
console.log(num);

// Output: 0.9272952180016122``````

## atan2() Syntax

The syntax of the `atan2()` method is:

``Math.atan2(x, y)``

Here, `tan()` is a static method. Hence, we are accessing the method using the class name, `Math`.

## atan2() Parameters

The `atan2()` method takes two parameters:

• `x` - number, which is divided by the parameter `y`
• `y` - number that divides the parameter `x`

Here, the method computes the arctangent of `x / y`.

## atan2() Return Value

The method returns:

• angle (in radians) after computing the arctan of `x / y`
• NaN (Not a Number) for non-numeric arguments `x` and `y`

Note: The returned angle will always be in the range `-π` to `π` for numeric arguments.

## Example 1: JavaScript Math.atan2()

``````// compute the arctangent of 5 / 2
let result1 = Math.atan2(5, 2);
console.log(result1);

// compute the arctangent of 0 / 5
let result2 = Math.atan(0, 5);
console.log(result2);

// Output:
// 1.1902899496825317
// 0``````

In the above example,

• `Math.atan2(5, 2)` - computes the arctan of 2.5 ( `5 / 2` )
• `Math.atan2(0, 5)` - computes the arctan of 0 ( `0 / 5` )

## Example 2: Math.atan2() with Infinity

``````// atan2() with positive infinity
let num = Math.atan2(Infinity, 0);
console.log(num);

// atan2() with negative infinity
let num = Math.atan2(-Infinity, 0);
console.log(num);

// atan2() with both infinities
let num = Math.atan2(Infinity, -Infinity);
console.log(num);

// Output:
// 1.5707963267948966 (π/2)
// -1.5707963267948966 (-π/2)
// 2.356194490192345 (3*π/4)``````

Here, you can see we have successfully used the `atan2()` method with infinity. And the result is still between and π even though we have used it with infinity.

## Example 3: Math.atan2() with Non-Numeric Arguments

``````// string variables
let str1 = "John";
let str2 = "Wick";

// atan2() with string arguments
let result = Math.atan2(str1, str2);
console.log(result);

// Output: NaN``````

The code above shows the use of the `atan2()` method with string arguments. That's why we get `NaN` as output.