So sánh S với 2
S = \(\dfrac{1}{2}+\dfrac{2}{2^2}+\dfrac{3}{2^3}+........+\dfrac{2017}{2^{2017}}\)
So sánh S với 2 biết :
S = \(\dfrac{1}{2}+\dfrac{2}{2^2}+\dfrac{3}{2^3}+...+\dfrac{2017}{2^{2017}}\)
CMR: S = \(\dfrac{1}{4}+\dfrac{2}{4^2}+\dfrac{3}{4^3}+\dfrac{4}{4^4}+...+\dfrac{2016}{4^{2016}}+\dfrac{2017}{4^{2017}}\)< \(\dfrac{1}{2}\)
Đề bài: So sánh
1, \(\dfrac{2017}{2018}+\dfrac{2018}{2019}+\dfrac{2019}{2020}với\) 3
2, \(\dfrac{2017}{2018}+\dfrac{2018}{2019}với\dfrac{2017+2018}{2018+2019}\)
Cho tổng T = \(\dfrac{2}{2^1}\)+\(\dfrac{3}{2^2}\)+\(\dfrac{4}{2^3}\)+...+\(\dfrac{2016}{2^{2015}}\)+\(\dfrac{2017}{2^{2016}}\)
So sánh T với 3
Tính
A=\(\dfrac{\dfrac{2017}{2}+\dfrac{2017}{3}+\dfrac{2017}{4}+...+\dfrac{2017}{2018}}{\dfrac{2017}{1}+\dfrac{2016}{2}+...+\dfrac{1}{2017}}\)
tính tổng A=\(\dfrac{3}{5}+\dfrac{3}{5^2}+\dfrac{3}{5^3}+...+\dfrac{3}{5^{201}}\)
B=\(1^3+2^3+3^3+...+2017^3\)
cho B=\(\dfrac{1}{2^2}+\dfrac{1}{3^2}+\dfrac{1}{4^2}+...+\dfrac{1}{100^2}\)
so sánh B với 1
So sánh
\(A=\dfrac{1}{2^2}+\dfrac{2}{2^3}+\dfrac{3}{2^4}+...+\dfrac{100}{2^{201}}\)
và \(B=\dfrac{1}{2^3}+\dfrac{1}{3^3}+\dfrac{1}{4^3}+...+\dfrac{1}{100^3}\)