function vercos( x ) {
	return 1.0 + cos( x );
}
Computes the versed cosine.

@param {number} x - input value (in radians)
@returns {number} versed cosine

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

@example
var v = vercos( 3.141592653589793/2.0 );
// returns 1.0

@example
var v = vercos( -3.141592653589793/6.0 );
// returns ~1.8660

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