B = \(\frac{1}{1008}-\frac{1}{2014}+\frac{1}{1009}-\frac{1}{2013}+...+\frac{1}{2014}-\frac{1}{1008}\)
\(\Rightarrow\)B= 0
B = \(\frac{1}{1008}-\frac{1}{2014}+\frac{1}{1009}-\frac{1}{2013}+...+\frac{1}{2014}-\frac{1}{1008}\)
\(\Rightarrow\)B= 0
Tính tổng sau:\(A=\frac{1}{2016\times2015}+\frac{1}{2015\times2014}+\frac{1}{2014\times2013}+..........+\frac{1}{2}\)
Giúp mình làm nha, ai nhanh mình sẽ "tờ ích tích sắc tích" cho. Chúc các bạn học tốt!!!
CMR :
\(1-\frac{1}{2}+\frac{1}{3}-\frac{1}{4}+\frac{1}{5}-\frac{1}{6}+...+\frac{1}{2013}-\frac{1}{2014}=\frac{1}{1008}+\frac{1}{1009}+\frac{1}{1010}+...+\frac{1}{2014}\)
Cho \(C=1-\frac{1}{2}+\frac{1}{3}-\frac{1}{4}+........-\frac{1}{2014}\)va \(D=\frac{1}{1008}+\frac{1}{1009}+\frac{1}{1010}+........+\frac{1}{2014}\)tinh \(\left(\frac{C}{D}\right)^{2015}\)
cho hỏi: A=\(\frac{1}{1\cdot2}+\frac{1}{3\cdot4}+\frac{1}{5\cdot6}+...+\frac{1}{2015\cdot2016}\)
B=\(\frac{1}{1008}+\frac{1}{1009}+\frac{1}{1010}+...+\frac{1}{2016}\)
Tính B-A
Ai giúp cảm ơn!
cho hỏi : A=\(\frac{1}{1\cdot2}+\frac{1}{3\cdot4}+\frac{1}{5\cdot6}+...+\frac{1}{2015\cdot2016}\)
B=\(\frac{1}{1008}+\frac{1}{1009}+\frac{1}{1010}+...+\frac{1}{2016}\)
tính B-A
giúp vs nha,cảm ơn nhìu!
\(1+\frac{1}{1+2}+\frac{1}{1+2+3}+\frac{1}{1+2+3+4}+.....+\frac{2\times2012}{1+2+3+4+.....+2012}\)
Ai làm xong trước thì mình sẽ tick cho nha
cho biết \(A=\frac{2016^2+1^2}{2016.1}+\frac{2015^2+2^2}{2015.2}+\frac{2014^2+3^2}{2014.3}+...+\frac{1009^2+1008^2}{1009.1008}\) ;B=\(\frac{1+1+1+1+...+1+1}{2+3+4+..+2017}\)tìm \(\frac{A}{B}\)
Chứng tỏ \(\frac{A}{B}\) là một số nguyên biết :
\(A=\frac{1}{1\cdot2}+\frac{1}{3\cdot4}+\frac{1}{5\cdot6}+....+\frac{1}{2013\cdot2014}\)
\(B=\frac{1}{1008\cdot2014}+\frac{1}{1009\cdot2013}+\frac{1}{2010\cdot2012}+....+\frac{1}{2014\cdot1008}\)
Tính B=1/1008*2014 + 1/1009*2013 + 1/1010*2012 + ...+ 1/2014*1008