Ta có:
\(\frac{1}{31}+\frac{1}{32}+\frac{1}{33}+...+\frac{1}{60}< \frac{1}{60}+\frac{1}{60}+...+\frac{1}{60}\left(có30số\right)\)
\(\Rightarrow\frac{1}{31}+\frac{1}{32}+\frac{1}{33}+...+\frac{1}{60}< \frac{1}{60}\cdot30=\frac{1}{2}< \frac{4}{5}\)\(\Rightarrow S< \frac{4}{5}\)
Cho
S= \(\frac{1}{31}\)+ \(\frac{1}{32}\)+...+ \(\frac{1}{60}\)
Chúng minh rằng \(\frac{3}{5}\)< S < \(\frac{4}{5}\)
Cho S = \(\frac{1}{13}\)+\(\frac{1}{32}\)+ ...................+\(\frac{1}{60}\)
Chứng minh \(\frac{3}{5}\)< S < \(\frac{4}{5}\)
So sánh
A=\(\frac{30^{31}+1}{30^{32}+1}\) và B=\(\frac{30^{32}+1}{30^{33}+1}\)
cho A= \(\frac{1}{31}+\frac{1}{32}+\frac{1}{33}+...+\frac{1}{60}\)
CM: A > 7/12
So sánh
A=\(\frac{30^{31}+1}{30^{32}+1}\) và B=\(\frac{30^{32}+1}{30^{33}+1}\)
Help me!Mk đg cần rất gấp ai nhanh mk tick cho
so sánh:
\(P=\frac{31}{2}.\frac{32}{2}.\frac{33}{2}...\frac{60}{2}\)và \(Q=1.3.5.7...59\)
cho S = \(\frac{2}{2^1}+\frac{3}{2^2}+\frac{4}{2^3}+.....+\frac{2010}{2^{2009}}+\frac{2011}{2^{2010}}\)
SO SÁNH S VỚI 3
cho \(S=1+\frac{1}{2}+\frac{1}{2^2}+\frac{1}{2^3}+...+\frac{1}{2^{2014}}\)
so sánh S với 2
\(2+\frac{1}{8}+\frac{1}{32}+\frac{1}{72}+\frac{1}{128}+\frac{1}{200}+\frac{1}{288}< \frac{9}{4}\)
P/s làm ơn mai em kiểm tra òi
