function acoversin( x ) {
	return asin( 1.0 - x );
}
Computes the inverse coversed sine.

@param {number} x - input value
@returns {number} inverse coversed sine

@example
var v = acoversin( 0.0 );
// returns ~1.5708

@example
var v = acoversin( 3.141592653589793/2.0 );
// returns ~-0.6075

@example
var v = acoversin( 3.141592653589793/6.0 );
// returns ~0.4966

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