# asinh

Compute the hyperbolic arcsine of a number.

## Usage

``````var asinh = require( '@stdlib/fastmath/special/asinh' );
``````

#### asinh( x )

Computes the hyperbolic arcsine of a `number` (in radians).

``````var v = asinh( 0.0 );
// returns 0.0

v = asinh( -0.0 );
// returns -0.0

v = asinh( 2.0 );
// returns ~1.444

v = asinh( -2.0 );
// returns ~-1.444

v = asinh( NaN );
// returns NaN

v = asinh( -Infinity );
// returns -Infinity

v = asinh( Infinity );
// returns Infinity
``````

## Notes

• For large `x`, the function will overflow.

``````var v = asinh( 1.0e200 );
// returns Infinity
// expected 461.2101657793691
``````
• For small `x`, the function will underflow.

``````var v = asinh( 1.0e-50 );
// returns 0.0
// expected 1.0e-50
``````

## Examples

``````var linspace = require( '@stdlib/math/utils/linspace' );
var asinh = require( '@stdlib/fastmath/special/asinh' );

var x = linspace( -5.0, 5.0, 103 );
var i;

for ( i = 0; i < x.length; i++ ) {
console.log( asinh( x[ i ] ) );
}
``````