http://www.math15.com/bbs/ wenxing15@qq.com 12 2009-07-16 22:36:21 Discuz! 7.0.0 http://www.math15.com/bbs/thread-4018-1-1.html 我不是对数联有意见,只是希望数联越办越好! 2009-07-12 10:30:29 2009-07-16 17:04:43 2 15 16 0 http://www.math15.com/bbs/thread-3944-1-1.html 一点建议 2009-07-04 09:47:04 2009-07-16 17:05:04 6 36 16 0 http://www.math15.com/bbs/thread-3964-1-1.html 数学知识普及免费在线讲座投票(在线免费学习报名) 2009-07-07 05:55:15 2009-07-16 20:50:50 18 179 16 0 http://www.math15.com/bbs/thread-4043-1-1.html 指点一下数联的积分是怎么得到的 2009-07-13 20:57:28 2009-07-16 17:06:05 1 7 110 0 http://www.math15.com/bbs/thread-3943-1-1.html 数联老会员进来 看看 2009-07-03 23:00:35 2009-07-16 18:10:15 6 27 110 0 http://www.math15.com/bbs/thread-3672-1-1.html 数学奥林匹克问题高248 2009-04-17 18:24:44 2009-07-16 16:43:53 1 172 183 0 http://www.math15.com/bbs/thread-4068-1-1.html 证明：对n≥4，每一个有外接圆的四边形，总可以划分... 2009-07-16 12:28:08 2009-07-16 12:28:08 0 7 194 0 http://www.math15.com/bbs/thread-3908-1-1.html 求∠DEB的度数 2009-06-25 21:49:40 2009-07-16 21:06:54 3 162 194 0 http://www.math15.com/bbs/thread-4061-1-1.html 求方程tan19x=(cos96°+sin96°)/(cos96°-sin96°)... 2009-07-15 05:51:06 2009-07-16 10:39:42 1 24 195 0 http://www.math15.com/bbs/thread-4060-1-1.html 已知凸四边形的四个内角A、B、C、D满足tgA+tgB+tgC+tgD=0... 2009-07-15 05:49:10 2009-07-16 10:41:13 1 18 195 0 http://www.math15.com/bbs/thread-4059-1-1.html 设△ABC为一锐角三角形,且A、B、C满足... 2009-07-15 05:48:20 2009-07-16 10:44:41 1 14 195 0 http://www.math15.com/bbs/thread-4058-1-1.html 在线段 AD上取二点 B和 C，使 AB=BC=CD．以 Bc为直径作圆... 2009-07-15 05:46:42 2009-07-16 10:46:25 1 17 195 0 http://www.math15.com/bbs/thread-4057-1-1.html 求函数y=(2sina-cos2a+3)/(4(sina)^2+4)的最值 2009-07-15 05:45:12 2009-07-16 10:48:06 1 20 195 0 http://www.math15.com/bbs/thread-4062-1-1.html 已知20个数1,2,…,20．两个游戏者轮流将"+"号或... 2009-07-16 12:15:01 2009-07-16 12:15:01 0 7 195 0 http://www.math15.com/bbs/thread-4063-1-1.html 设△ABC的三内角A、B、C成等差数列，三条边长a、b、c... 2009-07-16 12:16:15 2009-07-16 12:16:15 0 6 195 0 http://www.math15.com/bbs/thread-4064-1-1.html 设a1，a2，…an为实常数，x为实为数，且... 2009-07-16 12:19:18 2009-07-16 12:19:18 0 6 195 0 http://www.math15.com/bbs/thread-4065-1-1.html 设0＜α＜π/2，0＜β＜π/2，证明... 2009-07-16 12:22:31 2009-07-16 12:22:31 0 3 195 0 http://www.math15.com/bbs/thread-4066-1-1.html 求10cot(arc cot3+arc cot7+arc cot13+ arc cot21)的值． 2009-07-16 12:24:13 2009-07-16 12:24:13 0 4 195 0 http://www.math15.com/bbs/thread-4067-1-1.html 已知若干个红色的和若干个蓝色的点，将它们的某些点... 2009-07-16 12:25:13 2009-07-16 12:25:13 0 4 195 0 http://www.math15.com/bbs/thread-4069-1-1.html 散步时，每步长为1，向南、北、东、西任一方向均可... 2009-07-16 12:35:29 2009-07-16 12:35:29 0 5 195 0 http://www.math15.com/bbs/thread-4070-1-1.html 设整数n≥4,a1,a2,…,an是区间(0,2n)中的不同整数... 2009-07-16 12:37:06 2009-07-16 12:37:06 0 6 195 0 http://www.math15.com/bbs/thread-4081-1-1.html 2009IMO第一题 2009-07-16 21:52:14 2009-07-16 21:52:14 0 1 202 0 http://www.math15.com/bbs/thread-4082-1-1.html 2009IMO第二题 2009-07-16 21:54:02 2009-07-16 21:54:02 0 1 202 0 http://www.math15.com/bbs/thread-4083-1-1.html 2009IMO第三题 2009-07-16 22:02:56 2009-07-16 22:02:56 0 1 202 0