|X-1|与|Y-2|互为相反数,计算1/XY+1/(X+1)(Y+1)+---+1/(X+2009)(Y+2009)的值_数学解答

|X-1|与|Y-2|互为相反数,计算1/XY+1/(X+1)(Y+1)+---+1/(X+2009)(Y+2009)的值

人气：190 ℃　时间：2020-02-04 06:46:35

解答

|X-1|与|Y-2|互为相反数 |X-1|=0与|Y-2|=0 x=1 y=2 1/1*2+1/2*3+1/3*4+---+1/2010*2011 =1-1/2+1/2-1/3+1/3-1/4+---+1/2010-1/2011 =1-1/2011 =2010/2011