# j1
> Compute the [Bessel function of the first kind][bessel-first-kind] of order one.
The [Bessel function of the first kind][bessel-first-kind] of order one is defined as
## Usage
```javascript
var j1 = require( '@stdlib/math/base/special/besselj1' );
```
#### j1( x )
Computes the [Bessel function of the first kind][bessel-first-kind] of order one at `x`.
```javascript
var v = j1( 0.0 );
// returns 0.0
v = j1( 1.0 );
// returns ~0.440
v = j1( Infinity );
// returns 0.0
v = j1( -Infinity );
// returns 0.0
v = j1( NaN );
// returns NaN
```
## Examples
```javascript
var randu = require( '@stdlib/random/base/randu' );
var j1 = require( '@stdlib/math/base/special/besselj1' );
var x;
var i;
for ( i = 0; i < 100; i++ ) {
x = randu() * 10.0;
console.log( 'j1(%d) = %d', x, j1( x ) );
}
```
[bessel-first-kind]: https://en.wikipedia.org/wiki/Bessel_function#Bessel_functions_of_the_first_kind:_J.CE.B1
