function asec( x ) {
	return acos( 1.0 / x );
}
Computes the inverse (arc) secant of a number.

## Method

```tex
\operatorname{asec}(x) = \operatorname{acos}(\frac{1}{x})
```

@param {number} x - input value
@returns {number} inverse (arc) secant

@example
var v = asec( 1.0 );
// returns 0.0

@example
var v = asec( 2.0 );
// returns ~1.0472

@example
var v = asec( NaN );
// returns NaN