# JavaScript Math tan()

The JavaScript Math.tan() function returns the tangent of a specified number.

The syntax of the `Math.tan()` function is:

``Math.tan(x)``

`tan()`, being a static method, is called using the `Math` class name.

## Math.tan() Parameters

The `Math.tan()` function takes in:

• x - A number (in radians) whose tangent value is required.

## Return value from Math.tan()

• Returns the tangent of a given angle (in radians).

## Example 1: Using Math.tan()

``````// tangent of 1 radian
var value1 = Math.tan(1);
console.log(value1); // Output: 1.5574077246549023

var value2 = Math.tan(-2);
console.log(value2); // Output: 2.185039863261519

// Math constants can be used
var value3 = Math.cos(Math.PI);
console.log(value3); // Output: -1``````

Output

```1.5574077246549023
2.185039863261519
-1```

## Example 2: Using Math.tan() with degrees

``````// custom function for angle in degrees
function tan(degrees) {
var radians = (degrees * Math.PI) / 180;
}

// tangent of 57 degrees
value1 = tan(57);
console.log(value1); // Output: 1.5398649638145825

value2 = tan(0);
console.log(value2); // Output: 0

value3 = tan(45);
console.log(value3); // Output: 0.9999999999999999``````

Output

```1.5398649638145825
0
0.9999999999999999```

In the example above, we have defined a function that converts the degree value to radian and then passes it to `Math.tan()`.

Here, `tan(45)` gives 0.99999999999999 instead of 1 because floats are not stored perfectly in memory.

We can define custom functions in similar ways to extend the capabilities of such built-in functions.