根号(a-1)+(ab-2)^2=0
a-1=0
ab-2=0
a=1
b=2
1/ab+1/(a+1)(b+1)+1/(a+2)(b+2)+……+1/(a+2004)(b+2004)
=1/1*2+1/2*3+1/3*4+-------+1/2005*2006
=1-1/2+1/2-1/3+1/3-1/4+------+1/2005-1/2006
=1-1/2006
=2005/2006
根号(a-1)+(ab-2)^2=0
a-1=0
ab-2=0
a=1
b=2
1/ab+1/(a+1)(b+1)+1/(a+2)(b+2)+……+1/(a+2004)(b+2004)
=1/1*2+1/2*3+1/3*4+-------+1/2005*2006
=1-1/2+1/2-1/3+1/3-1/4+------+1/2005-1/2006
=1-1/2006
=2005/2006