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显示全部楼层 · 2011-10-7 19:22:37

a2 = 1/(1 - a1)a3 = 1/(1 - a2) = 1/[1 - 1/(1 - a1)] = 1 - 1/a1a4 = 1/(1 - a3) = 1/[1 - (1 - 1/a1)]= a1所以 an + 3 = an( n + 3 和 n 都是下标)所以 a2003 = a2000 = a1997 = ...= a2，a2004 = a2001= a1998 = ... = a3，所以 a2003 - a2004 = a2 - a3 = 1/2 - 2 = -3/2...

千问 · 2011-10-7 19:22:37

应该是1吧因为a2003-a2004 =a（2003-2004）=a（-1）又因为a1=-1 ，则-1x-1=1没把握...

千问 · 2011-10-7 19:22:37

a1=-1a2=1/2a3=2a4=-1依此类推
a2003= 1/2
a2004=2它们的差为 -3/2
看清是负的...

千问 · 2011-10-7 19:22:37

a2003-a2004=3/2...

千问 · 2011-10-7 19:22:37

应该是-3/2。因为：a1=-1；a2=1/2;a3=2;a4=-1;a5=1/2;a6=2..........以此一下,每三个一组重复.那么2003/3=667余2,a2003=1/2;2004/3=668,a2004=2; a2003-a2004=1/2-2=-3/2....