Cho \(S=\frac{1}{4}+\frac{2}{4^2}+\frac{3}{4^3}+...+\frac{2016}{4^{2016}}\)
Chứng minh rằng : \(S<\frac{1}{2}\)
Cho M=\(\frac{1}{4}-\frac{2}{4^2}+\frac{3}{4^3}-\frac{4}{4^4}+...+\frac{2015}{4^{2015}}-\frac{2016}{4^{2016}}\).Chứng minh M<\(\frac{4}{25}\)
Cho tổng gồm 2016 số hạng : S= \(\frac{1}{4}\)+ \(\frac{2}{4^2}\)+ \(\frac{3}{4^3}\)+ \(\frac{4}{4^4}\)+ ....... + \(\frac{20166}{4^{2016}}\). Chứng minh rằng: S < \(\frac{1}{2}\)
chứng minh S = \(\frac{1}{1}-\frac{1}{2}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{2015}-\frac{1}{2016}\)
Rút gọn:
\(\frac{2016-\frac{1}{2}-\frac{1}{3}-\frac{1}{4}-...-\frac{1}{2017}}{\frac{1}{2}+\frac{2}{3}+\frac{3}{4}+...+\frac{2015}{2016}}\)
Chứng minh
\(1+\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{2^{2016}-2}+\frac{1}{2^{2016}-1}>1008\)
Cho biểu thức sau: \(P=\frac{1}{5}+\frac{2}{5^2}+\frac{3}{5^3}+\frac{4}{5^4}+.....+\frac{2015}{5^{2015}}+\frac{2016}{5^{2016}}\)
Chứng minh 1/4 < P< 1/3
Tính tổng:
\(S=\frac{1}{1+2}+\frac{1}{1+2+3}+\frac{1}{1+2+3+4}+...+\frac{1}{1+2+3+4+...+2016+2017}\)
Tính A= \(\frac{1}{4}+\frac{2}{4^2}+\frac{3}{4^3}+...+\frac{2016}{4^{2016}}\)