function acot( x ) {
	return atan( 1.0 / x );
}
Computes the inverse cotangent of a double-precision floating-point number.

@param {number} x - input value
@returns {number} inverse cotangent (in radians)

@example
var v = acot( 2.0 );
// returns ~0.4636

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

@example
var v = acot( 0.5 );
// returns ~1.1071

@example
var v = acot( 1.0 );
// returns ~0.7854

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

@example
var v = acot( Infinity );
// returns 0.0