Question

2015/4034 < 1/2²+1/3²+1/4²+...+1/2016² < 2015/2016

Answer 1

1/2.3 +1/3.4+...+1/2016.2017 < 1/2^2+1/3^2+...+1/2016^2

1/2 -1/3+1/3 -1/4+...+1/2016-1/2017 <  1/2^2+1/3^2+...+1/2016^2

1/2-1/2017 <  1/2^2+1/3^2+...+1/2016^2

=> 2015/4034 < 1/2^2+1/3^2+...+1/2016^2

tương tự

 1/2^2+1/3^2+...+1/2016^2 < 1/1.2 +1/2.3+...+1/2015.2016

 1/2^2+1/3^2+...+1/2016^2 < 1- 1/2+1/2 -1/3+...+1/2015- 1/2016

 1/2^2+1/3^2+...+1/2016^2 < 1-1/2016

 1/2^2+1/3^2+...+1/2016^2 < 2015/2016

tích nha

Answer 2

nhìn cậu ngốc quáạ

Answer 3

ai ngốc bằng thằng này không các bn

Answer 4

Ta có : 1/2.3<1/2^2<1/1.2 ;1/3.4<1/3^2,1/2.3 ;1/4.5<1/4^2<1/3.4 ;......; 1/2016.2017<1/2016^2<1/2015.2016 

=>1/2.3+1/3.4+1/4.5+..1/2016.2017<1/2^2+1/3^2+1/4^2+...+1/2016^2<1/1.2+1/2.3+1/3.4+..+1/2015*2016

=>1/2-1/3+1/3-1/4+1/4-1/5+..+1/2016-1/2017<1/2^2+1/3^+...+1/2016^2<1/1-1/2+1/2-1/3+1/3-1/4+...+1/2015-1/2016

=>1/2-1/2017<1/2^2+1/3^2+1/4^2+...+1/2016^2<1/1-1/2016

=.2015/4034<1/2^2+1/3^2+1/4^....+1/2016^2<2015/2016

k cho mình nha các bạn