# exp2
> Base `2` [exponential function][exponential-function].
## Usage
```javascript
var exp2 = require( '@stdlib/math/base/special/exp2' );
```
#### exp2( x )
Evaluates the base `2` [exponential function][exponential-function].
```javascript
var v = exp2( 3.0 );
// returns 8.0
v = exp2( -9.0 );
// returns ~0.002
v = exp2( 0.0 );
// returns 1.0
v = exp2( NaN );
// returns NaN
```
## Examples
```javascript
var randu = require( '@stdlib/random/base/randu' );
var exp2 = require( '@stdlib/math/base/special/exp2' );
var x;
var i;
for ( i = 0; i < 100; i++ ) {
x = (randu()*100.0) - 50.0;
console.log( '2^%d = %d', x, exp2( x ) );
}
```
[exponential-function]: https://en.wikipedia.org/wiki/Exponential_function