# tanh
> Compute the [hyperbolic tangent][hyperbolic-tangent] of a number.
## Usage
```javascript
var tanh = require( '@stdlib/math/base/special/tanh' );
```
#### tanh( x )
Computes the [hyperbolic tangent][hyperbolic-tangent] of a `number` (in radians).
```javascript
var v = tanh( 0.0 );
// returns 0.0
v = tanh( -0.0 );
// returns -0.0
v = tanh( 2.0 );
// returns ~0.964
v = tanh( -2.0 );
// returns ~-0.964
v = tanh( NaN );
// returns NaN
```
## Examples
```javascript
var linspace = require( '@stdlib/array/linspace' );
var tanh = require( '@stdlib/math/base/special/tanh' );
var x = linspace( -4.0, 4.0, 100 );
var i;
for ( i = 0; i < x.length; i++ ) {
console.log( tanh( x[ i ] ) );
}
```
[hyperbolic-tangent]: http://mathworld.wolfram.com/HyperbolicTangent.html