如果有理数x,y满足|x-1|+(xy-2)2=0. (1)求x,y的值; (2)试求1/xy+1/(x+1)(y+1)+1/(x+2)(y+2)+…+1/(x+2009)(y+2009)的值.
问题描述:
如果有理数x,y满足|x-1|+(xy-2)2=0.
(1)求x,y的值;
(2)试求
+1 xy
+1 (x+1)(y+1)
+…+1 (x+2)(y+2)
的值. 1 (x+2009)(y+2009)
答
(1)∵x-1|≥0,(xy-2)2≥0,又|x-1|+(xy-2)2=0∴|x-1|=0;(xy-2)2=0∴x=1,y=2;(2)原式=12+12×3+13×4+14×5+…+12010×2011=12+12-13+13-14+14-15+…+12009-12010+12010-12011=20102011....