计算1/a(a+1)+1/(a+1)(a+2)+1/(a+2)(a+3)+.+1/(a+2012)(a+2013)

问题描述:

计算1/a(a+1)+1/(a+1)(a+2)+1/(a+2)(a+3)+.+1/(a+2012)(a+2013)

原式=1/a-1/(a+1)+1/(a+1)-1/(a+2)+1/(a+2)-1/(a+3)+.+1/(a+2012)-1/(a+2013)
=1/a-1/(a+2013)
=2013/(a²+2013a)