function coversin( x ) {
	return 1.0 - sin( x );
}
Computes the coversed sine.

@param {number} x - input value (in radians)
@returns {number} coversed sine

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

@example
var v = coversin( 3.141592653589793/2.0 );
// returns 0.0

@example
var v = coversin( -3.141592653589793/6.0 );
// returns 1.5

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