To find the arctangent, or inverse tangent, of a number, we can use the JavaScript **atan()** function from the math module.

`Math.atan(x)`

In JavaScript, we can easily use trigonometric functions with the JavaScript math module. The JavaScript math module allows us to perform trigonometry easily.

With the JavaScript math module, we can find the arctangent of a number easily.

To find the arctangent of a number, we use the math **atan()** function.

Below is the JavaScript syntax to find the inverse tangent of a number.

`Math.atan(x)`

The input to the **atan()** function must be a numeric value. The return value will be a numeric value between -pi/2 and pi/2 radians.

```
console.log(Math.atan(5))
console.log(Math.atan(0))
console.log(Math.atan(-3))
// Output:
1.373400766945016
0.0
-1.2490457723982544
```

## Finding the Inverse Tangent of a Number in JavaScript

Arctangent is defined as the inverse of the tangent of a number.

Below, we show that if we pass a number to **tan()** and then call the JavaScript **atan()** function, we get back the same number.

```
console.log(Math.atan(math.tan(math.PI/3)))
console.log(Math.PI/3)
// Output:
1.0471975511965976
1.0471975511965976
```

## Find Arc Tangent of the Quotient of Two Arguments with atan2() in JavaScript

JavaScript gives us the ability to find the arctangent of the quotient of two numbers, where the two numbers represents the coordinates of a point (x,y). To find the arctangent of a the quotient of two numbers, we use the math **atan2()** function.

Below is the JavaScript syntax to find the inverse tangent of the quotient of two numbers.

`Math.atan2(x)`

The inputs to the **atan2()** function must be a numeric values. The return value will be a numeric value between -pi and pi.

```
console.log(Math.atan2(5,1))
console.log(Math.atan2(0,0))
console.log(Math.atan2(-3,7))
// Output:
1.373400766945016
0.0
-0.40489178628508343
```

Hopefully this article has been beneficial for you to understand how to use the math **atan()** function in JavaScript to find the arctangent of a number.