Question

chung minh rang;

1/2mu2+1/3mu2+1/4mu2+...+1/2005mu2<1/2

Answer 1

1/2^2+1/3^2+1/4^2+....+1/2005^2

ta có vì:1/2^2<1/2; 1/3^2 <1/2.....;1/2005^2<1/2

suy ra 1/2^2+1/3^2+1/4^2+....+1/2005^2<1/2