三角函数

//弧度=角度*Math.PI/180;

//角度=弧度*180/Math.PI;

var speed:Number = 5;
addEventListener(Event.ENTER_FRAME,onEnterFrame);
function onEnterFrame(event:Event):void
{
	var dx:Number = mouseX - ball.x;
	var dy:Number = mouseY - ball.y;
	var angle:Number = Math.atan2(dy,dx);
	var dist:Number = Math.sqrt(dx * dx + dy * dy);
	ball.rotation = angle * 180 / Math.PI;
	var vx:Number = Math.cos(angle) * speed;
	var vy:Number = Math.sin(angle) * speed;
	ball.x +=  vx;
	ball.y +=  vy;
}