Question

计算(1-1/2-1/3-...-1/2010)*(1/2+1/3+..+1/2011)-(1-1/2-1/3-...-

Answer 1

令k=1/2+1/3+...+1/2010,则原式=(1-k)(k+1/2011)-(1-k-1/2011)k

=(k+1/2011-k^2-k/2011)-(k-k^2-k/2011)

=1/2011