先发一不分//有空再补全~~
class Math2 {
 var x_:Number;
 var y_:Number;
 var z_:Number;
 function MAth2 (a, b) {
  var point = {x:a, y:b};
 }
 //角度弧度转换
 function angle_radian (a, blo) {
  var new_val;
  blo ? new_val = a * 180 / Math.PI : new_val = a*Math.PI / 180;
  return new_val;
 }
 // 正弦（两角和差）
 function sin_2 (a, b, blo) {
  var new_val;
  blo ? new_val = Math.sin (a) * Math.cos (b) + Math.cos (a) * Math.sin (b) : new_val = Math.sin (a) * Math.cos (b) - Math.cos (a) * Math.sin (b);
  return new_val;
 }
 // 正弦2倍角
 function sin_ (a) {
  var new_val;
  new_val = a * Math.sin (a) * Math.cos (a);
  return new_val;
 }
 //正弦半角
 function sin_h (a) {
  var new_val:Object = new Object ();
  var tmp;
  tmp = Math.abs ((1 + Math.cos (a)) / 2);
  new_val = {minus:tmp, positive:-tmp};
  return new_val;
 }
 //正弦平方
 function sin_pow_ab (a, b) {
  var new_val;
  new_val = -.5 * (Math.cos (a + b) - Math.cos (a - b));
  return new_val;
 }
 // 余弦（两角和差）
 function cos_2 (a, b, blo) {
  var new_val;
  blo ? new_val = Math.cos (a) * Math.sin (b) - Math.sin (a) * Math.cos (b) : new_val = Math.cos (a) * Math.sin (b) + Math.sin (a) * Math.cos (b);
  return new_val;
 }
 //余弦2倍角
 function cos_ (a) {
  var new_val;
  new_val = Math.pow (Math.cos (a), 2) - Math.pow (Math.sin (a), 2);
  return new_val;
 }
 //余弦半角
 function cos_h (a) {
  var new_val:Object = new Object ();
  var tmp;
  tmp = Math.abs ((1 - Math.cos (a)) / 2);
  new_val = {minus:tmp, positive:-tmp};
  return new_val;
 }
 //余弦平方
 function cos_pow_ab (a, b) {
  var new_val;
  new_val = .5 * (Math.cos (a + b) + Math.cos (a - b));
  return new_val;
 }
 //正弦余弦成积
 function sina_cosb (a, b) {
  var new_val;
  new_val = .5 * (Math.sin (a + b) - Math.sin (a - b));
  return new_val;
 }
 ///////////////////////////////////////////////////////////
 //正切两角和差
 function tan_2 (a, b, blo) {
  var new_val;
  blo ? new_val = (Math.tan (a) + Math.tan (b)) / 1 - Math.tan (a) * Math.tan (b) : new_val = (Math.tan (a) - Math.tan (b)) / 1 + Math.tan (a) * Math.tan (b);
 }
 //正切2倍角
 function tan_ (a) {
  var new_val;
  new_val = 2 * Math.tan (a) / (1 - Math.pow (Math.tan (a), 2));
  return new_val;
 }
 //正切半角
 function tan_h (a) {
  var new_val:Object = new Object ();
  var tmp;
  tmp = Math.abs ((1 - Math.cos (a)) / (1 + Math.cos (a))) * Math.tan (a / 2);
  new_val = {minus:tmp, positive:-tmp};
  return new_val;
 }
}