已知：字母a、b满足√（a-1)+√(b-2)=0,求1／ab+1/(a+1)(b+1)+1/(a+2)(b+2)+……+1/(a+2009)(b+2009)

已知：字母a、b满足√（a-1)+√(b-2)=0,求1／ab+1/(a+1)(b+1)+1/(a+2)(b+2)+……+1/(a+2009)(b+2009)
已知：字母a、b满足√（a-1)+√(b-2)=0,求1／ab+1/(a+1)(b+1)+1/(a+2)(b+2)+……+1/(a+2009)(b+2009)

已知：字母a、b满足√（a-1)+√(b-2)=0,求1／ab+1/(a+1)(b+1)+1/(a+2)(b+2)+……+1/(a+2009)(b+2009)
√（a-1)+√(b-2)=0
a-1=b-2=0
a=1b=2
原式=1/1*2+1/2*3+……+1/2010*2011
=1-1/2+1/2-1/3+……+1/2010-1/2011
=1-1/2011
=2010/2011

2011\2012

无解

a-1=0,b-2=0
a=1,b=2
1／ab+1/(a+1)(b+1)+1/(a+2)(b+2)+……+1/(a+2009)(b+2009)
=1/1*2+1/2*3+..........+1/2010*2011
=1-1/2+1/2-1/3+.......+1/2010-1/2011
=1-1/2011
=2010/2011

a=1
b=2
1/1x2+1/2x3+1/3x4+1/4x5+········+1/2009x2010+1/2010x2011
=1-1/2+1/2-1/3+1/3-1/4+···········+1/2009-1/2010+1/2010-1/2011
=1-1/2011
=2010/2011
给不给分啊~~~~~！！！！
饿得不行了1-1...

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a=1
b=2
1/1x2+1/2x3+1/3x4+1/4x5+········+1/2009x2010+1/2010x2011
=1-1/2+1/2-1/3+1/3-1/4+···········+1/2009-1/2010+1/2010-1/2011
=1-1/2011
=2010/2011
给不给分啊~~~~~！！！！
饿得不行了

收起

由题的a=1，b=2 所以b=a+1
1/(a+n)-1/(b+n)=【b+n-(a+n)】/(a+n)(b+n)=（b-a）/(a+n)(b+n)=1/(a+n)(b+n)
所以
1／ab+1/(a+1)(b+1)+1/(a+2)(b+2)+……+1/(a+2009)(b+2009)
=1／ab+1/(a+1)-1/(b+1)+1/(a+2)-1/(b+2)+.....

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由题的a=1，b=2 所以b=a+1
1/(a+n)-1/(b+n)=【b+n-(a+n)】/(a+n)(b+n)=（b-a）/(a+n)(b+n)=1/(a+n)(b+n)
所以
1／ab+1/(a+1)(b+1)+1/(a+2)(b+2)+……+1/(a+2009)(b+2009)
=1／ab+1/(a+1)-1/(b+1)+1/(a+2)-1/(b+2)+......+1/(a+2009)-1/(b+2009)
=1/2+1/2-1/3+1/3-1/4+.....+1/2010-1/2011
=1-1/2011
=2010/2011

收起