Quart.as 542 Bytes
package com.greensock.easing {
	
	public class Quart {
		public static const power:uint = 3;
		
		public static function easeIn (t:Number, b:Number, c:Number, d:Number):Number {
			return c*(t/=d)*t*t*t + b;
		}
		public static function easeOut (t:Number, b:Number, c:Number, d:Number):Number {
			return -c * ((t=t/d-1)*t*t*t - 1) + b;
		}
		public static function easeInOut (t:Number, b:Number, c:Number, d:Number):Number {
			if ((t/=d*0.5) < 1) return c*0.5*t*t*t*t + b;
			return -c*0.5 * ((t-=2)*t*t*t - 2) + b;
		}
	}
}