Chứng minh:\(S=\frac{1}{2^2}+\frac{1}{3^2}+\frac{1}{4^2}+........+\frac{1}{2014^2}< \frac{2013}{2014}\)
tính GTBT D=\(\frac{\frac{2013}{2}+\frac{2013}{3}+\frac{2013}{4}+...+\frac{2013}{2014}}{\frac{2013}{1}+\frac{2012}{2}+\frac{2011}{3}+...+\frac{1}{2013}}\)
Chứng minh rằng : \(\frac{1}{4028}< \left(\frac{1}{2}.\frac{3}{4}.....\frac{2011}{2012}.\frac{2013}{2014}\right)^2< \frac{1}{2015}\)
cmr \(s< \frac{1}{3}\)biết \(S=\frac{1}{5}+\frac{2}{5^2}+\frac{3}{5^3}+...+\frac{2013}{5^{2013}}+\frac{2014}{5^{2014}}\)
\(A=\frac{1}{2}+\left(\frac{1}{2}\right)^2\left(\frac{1}{2}\right)^3+...+\left(\frac{1}{2}\right)^{2013}+\left(\frac{1}{2}\right)^{2014}\)
Chứng minh A< 1
(\(\left(\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{2014}\right)x=\frac{2013}{1}+\frac{2012}{2}+...+\frac{2}{2012}+\frac{1}{2013}\)
tìm x
a , | 3 - 2x | = x + 1
b , \(\left(\frac{1}{2}+\frac{1}{3}+.....+\frac{1}{2014}\right).x=\frac{2013}{1}+\frac{2012}{2}+......+\frac{2}{2012}+\frac{1}{2013}\)
\(\left(1+\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{2013}\right)x+2013=\frac{2014}{1}+\frac{2015}{2}+...+\frac{4025}{2012}+\frac{4026}{2013}\)
\(\left(\frac{1}{2}+\frac{1}{3}+...+\frac{1}{2014}\right).x=\frac{2013}{1}+\frac{2012}{2}+...+\frac{2}{2012}+\frac{1}{2013}\)Tìm x biết: