... you!http://www.batdangthuc.net/forum/showthread.php?t=26http://www.batdangthuc.net/forum/showthread.php?t=26&page=2http://www.batdangthuc.net/forum/showthread.php?t=26&page=3http://www.batdangthuc.net/forum/showthread.php?t=26&page=4http://www.batdangthuc.net/forum/showthread.php?t=26&page=5http://www.batdangthuc.net/forum/showthread.php?t=26&page=6For ... you!http://www.batdangthuc.net/forum/showthread.php?t=26http://www.batdangthuc.net/forum/showthread.php?t=26&page=2http://www.batdangthuc.net/forum/showthread.php?t=26&page=3http://www.batdangthuc.net/forum/showthread.php?t=26&page=4http://www.batdangthuc.net/forum/showthread.php?t=26&page=5http://www.batdangthuc.net/forum/showthread.php?t=26&page=6For Further ... = r =1vp + s =2. Easy to refer (a, b, c, d)=(1, 1, 1, 1), (2, 1, 1, 0)or permutations. www.batdangthuc.net 9Example 30 (Brazilian Olympiad Revenge 2007). Let a, b, c ∈ R with abc =1. Provethata2+b2+c2+1a2+1b2+1c2+2a...
... 3 232 2 23b ba b cb a c 3 Chứng minh: *) Với n = 2, bấtđẳngthức ở dang: .2a ba b ; 0a b (1) Khi đó: 22 2(1) 2 44a bab a b ab ab ...