CMR: Với a,b,c,d dương; abcd=1 thì:
$\dfrac{1}{a^4+b^4+c^4+1}+\dfrac{1}{b^4+c^4+d^4+1}+\dfrac{1}{c^4+d^4+a^4+1}+\dfrac{1}{d^4+a^4+b^4+1}<\dfrac{1}{4}$
03-05-2010 - 06:35
23-04-2010 - 21:30
23-04-2010 - 20:45
23-04-2010 - 11:58
22-04-2010 - 06:36
Community Forum Software by IP.Board
Licensed to: Diễn đàn Toán học