\(3B=1+\frac{1}{3}+\frac{1}{3^2}+...+\frac{1}{3^{2004}}
\)
\(2B=1-\frac{1}{3^{2004}}\)
\(B=\frac{1}{2}-\frac{1}{2\cdot3^{2004}}\)
Do đó B<\(\frac{1}{2}\)
chúc thành công
Cho \(B=\frac{1}{3}+\frac{1}{3^2}+\frac{1}{3^3}+\frac{1}{3^4}+...+\frac{1}{3^{2005}}\)
CMR:\(B< \frac{1}{2}\)
Cho B=\(\frac{1}{3}+\frac{1}{3^2}+\frac{1}{3^3}+......+\frac{1}{3^{2005}}\)
CMR B < \(\frac{1}{2}\)
cho B=\(\frac{1}{3}+\frac{1}{3^2}+...+\frac{1}{2005}\)
CMR :B<\(\frac{1}{2}\)
Cho B= \(\frac{1}{3}+\frac{1}{3^2}+\frac{1}{3^3}+...+\frac{1}{3^{2004}}+\frac{1}{3^{2005}}\) . Chứng minh B<\(\frac{1}{2}\)
1, Tìm chữ số tận cùng của A=19^5^1^8^9^0 + 2^9^1^9^6^9 (lũy thừa tầng)
2, Cho B= \(\frac{1}{3}+\frac{1}{3^2}+\frac{1}{3^3}+\frac{1}{3^4}+...+\frac{1}{3^{2004}}+\frac{1}{3^{2005}}\)
CMR: B< \(\frac{1}{2}\)
CMR:
\(\frac{1}{2^3}+\frac{1}{3^3}+.....+\frac{1}{2005^3}+\frac{1}{2006^3}<\frac{1}{15}\)
cho B =\(\frac{1}{3}+\frac{1}{3^2}+\frac{1}{3^3}+\frac{1}{3^4}+...+\frac{1}{3^{2004}}+\frac{1}{3^{2005}}\)chứng minh rằng B < \(\frac{1}{2}\)
Tính
\(B=\frac{1}{3}+\frac{1}{3^2}+\frac{1}{3^3}+...+\frac{1}{3^{2015}}\)
\(P=\frac{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+\frac{1}{5}+...+\frac{1}{2005}}{\frac{2004}{1}+\frac{2003}{2}+\frac{2002}{3}+...+\frac{1}{2004}}\)
Cho B=\(\frac{1}{3}+\frac{1}{3^2}+\frac{1}{3^3}+\frac{1}{3^4}+...+\frac{1}{3^{2004}}+\frac{1}{3^{2005}}\)
CMR:B<\(\frac{1}{2}\)
