 # JavaScript Math tanh()

The `tanh()` method calculates the hyperbolic tangent of the specified number and returns it.

### Example

``````// hyperbolic tangent of 1
let number = Math.tanh(1);
console.log(number);

// Output: 0.7615941559557649``````

## tanh() Syntax

The syntax of the `Math.tanh()` method is:

``Math.tanh(number)``

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

## tanh() Parameters

The `tanh()` method takes a single parameter:

• `number` - whose hyperbolic tangent is to be calculated

## tanh() Return Value

The `tanh()` method returns:

• hyperbolic tangent of the given argument `number`
• NaN (Not a Number) for a non-numeric argument

## Example 1: JavaScript Math.tanh()

``````// hyperbolic tangent of negative number
let number1 = Math.tanh(-1);
console.log(number1);

// hyperbolic tangent of zero
let number2 = Math.tanh(0);
console.log(number2);

// hyperbolic tangent of positive number
let number3 = Math.tanh(2);
console.log(number3);

// Output:
// -0.7615941559557649
// 0
// 0.9640275800758169``````

In the above example, the `Math.tanh()` method computes the hyperbolic tangent of

• `-1` (negative number) - results in -0.7615941559557649
• `0` (zero) - results in 0
• `2` (positive number) - results in 0.9640275800758169

Note: Mathematically, the hyperbolic tangent is equal to (ex - e-x)/(ex + e-x).

## Example 2: Math.tanh() with Infinity Values

``````// tanh() with negative infinity
let number1 = Math.tanh(-Infinity);
console.log(number1);
// Output: -1

// tanh() with positive infinity
let number2 = Math.tanh(Infinity);
console.log(number2);
// Output: 1``````

Here, the `tanh()` method, when used with infinities, returns -1 (if the parameter is `-Infinity`) and 1 (if the parameter is `Infinity`).

## Example 3: Math.tanh() with Non-Numeric Argument

``````let string = "Harry";

// tanh() with string argument
let value = Math.tanh(string);
console.log(value);

// Output: NaN``````

In the above example, we have tried to calculate the hyperbolic tangent of the string `"Harry"`. That's why we get NaN as the output.