HMMT（Harvard-MIT数学竞赛）题（3星）

设S是平面上满足下列条件的点(a,b)组成的集：

1）0 ≤ a,b ≤ 1;
2) 方程 x^4 + ax^3 - bx^2 + ax + 1 有实数解。

求S的面积。

所有跟帖： 

• 康MM回来了？欢迎呀~~~~ -于德利- ♂ (0 bytes) () 03/14/2008 postreply 15:19:10

• 还在转时差 -康MM- ♀ (0 bytes) () 03/15/2008 postreply 06:15:30

• 回复：HMMT（Harvard-MIT数学竞赛）题（3星） -dynamic- ♂ (363 bytes) () 03/16/2008 postreply 20:37:30

• Excellent! -endofsuburbia- ♂ (0 bytes) () 03/17/2008 postreply 05:49:05

• 对了，一看就是MIT材料 -康MM- ♀ (0 bytes) () 03/17/2008 postreply 08:20:59

• 过奖了，谢谢:) -dynamic- ♂ (0 bytes) () 03/18/2008 postreply 11:26:39

• 欢迎回来！好题目，好解！ -乱弹- ♂ (0 bytes) () 03/17/2008 postreply 18:16:46

• Thanks. You guys are doing great here. -康MM- ♀ (0 bytes) () 03/18/2008 postreply 10:11:10

• Another method -sxcxm- ♂ (519 bytes) () 03/30/2008 postreply 14:51:36

• 回复：Another method -yma16- ♂ (46 bytes) () 04/01/2008 postreply 20:11:01

• 回复：回复：Another method -sxcxm- ♂ (747 bytes) () 04/02/2008 postreply 17:22:05

• 回复：回复：回复：Another method -yma16- ♂ (291 bytes) () 04/03/2008 postreply 09:02:18

• 回复：回复：Another method(Picture) (图) -sxcxm- ♂ (68 bytes) () 04/02/2008 postreply 17:33:10

• This is also a great solution.... -乱弹- ♂ (80 bytes) () 04/02/2008 postreply 20:33:22

• 回复：回复：Another method (图) -sxcxm- ♂ (79 bytes) () 04/04/2008 postreply 14:46:07

• My idea is (图) -sxcxm- ♂ (68 bytes) () 04/04/2008 postreply 14:48:15