# cosh
> Compute the [hyperbolic cosine][hyperbolic-cosine] of a number.
## Usage
```javascript
var cosh = require( '@stdlib/math/base/special/cosh' );
```
#### cosh( x )
Computes the [hyperbolic cosine][hyperbolic-cosine] of a `number` (in radians).
```javascript
var v = cosh( 0.0 );
// returns 1.0
v = cosh( 2.0 );
// returns ~3.762
v = cosh( -2.0 );
// returns ~3.762
v = cosh( 710.0 );
// returns Infinity
v = cosh( NaN );
// returns NaN
```
## Examples
```javascript
var linspace = require( '@stdlib/array/linspace' );
var cosh = require( '@stdlib/math/base/special/cosh' );
var x = linspace( -5.0, 5.0, 100 );
var i;
for ( i = 0; i < x.length; i++ ) {
console.log( cosh( x[ i ] ) );
}
```
[hyperbolic-cosine]: http://mathworld.wolfram.com/HyperbolicCosine.html