To find the tangent of a number (in radians), we can use the JavaScript **tan()** function from the math module.

`Math.tan(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 tangent of a number easily.

To find the tangent of a number, in radians, we use the math **tan()** function.

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

`Math.tan(x)`

The input to the **tan()** function must be a numeric value. The return value will be a numeric value between -infinity and infinity.

```
console.log(Math.tan(Math.PI/3))
console.log(Math.tan(0))
console.log(Math.tan(Math.PI/2))
// Output:
1.7320508075688767
0.0
1.633123935319537e+16
```

## Converting Degrees to Radians for Input into tan()

The **tan()** function takes a number in radians as input. If your data is in degrees, you will need to convert the values to radians.

To convert degrees to radians, we have to create our own function in JavaScript. Below is a function that will convert degrees to radians.

```
function degrees_to_radians(degrees) {
return degrees * (Math.PI/180);
}
```

If we have a value in degrees, we can use our new function to convert the value to radians and then pass it to the **sin()** function.

```
function degrees_to_radians(degrees) {
return degrees * (Math.PI/180);
}
console.log(Math.tan(degrees_to_radians(60)))
console.log(Math.tan(0))
console.log(Math.tan(degrees_to_radians(90)))
// Output:
1.7320508075688767
0.0
1.633123935319537e+16
```

## Finding the Inverse Tangent of a Number in JavaScript

The JavaScript math module also provides us trigonometric functions to find the inverses of the common trigonometric functions. The atan() function allows us to find 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
```

## Finding the Cotangent of a Number in JavaScript

To find the cotangent of a number, we can divide 1 by the tangentof the number.

We can find the cotangent of a number easily with the JavaScript **tan()** function. You can see how to find the cosecant of a number in the following JavaScript code.

```
console.log(1/Math.tan(Math.PI/3))
// Output:
0.577350269189626
```

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