cho b= \(\frac{1}{2^2}+\frac{1}{2^4}+\frac{1}{2^6}+........+\frac{1}{2^{98}}+\frac{1}{2^{100}}\)
chứng minh b< \(\frac{1}{3}\)
CHO B= \(1-\frac{1}{2^2}+\frac{1}{2^4}+\frac{1}{2^6}+.........+\frac{1}{2^{98}}+\frac{1}{2^{100}}\)
CHỨNG MINH B < \(\frac{1}{3}\)
a) Tính : A= 1 + 2 - 3 - 4 + 5 + 6 - 7 - 8 + ... + 97 + 98 - 99 - 100 + 101 + 102
b) Tìm số hữu tỉ x , biết : \(|1-2x|>7\)
c) Cho \(P=\frac{1}{5^2}+\frac{2}{5^3}+\frac{3}{5^4}+...+\frac{10}{5^{11}}+\frac{11}{5^{12}}\). Chứng tỏ \(P< \frac{1}{16}\)
Cho;A=\(\frac{1}{3^2}-\frac{1}{3^4}+\frac{1}{3^6}-\frac{1}{3^8}+......+\frac{1}{3^{98}}-\frac{1}{3^{100}}\)
Chứng tỏ:
1/1*2*3+1/2*3*4+1/3*4*5+....+1/98*99*100=4949/19800
Chứng minh rằng \(\frac{1}{8^2}-\frac{1}{8^4}+...+\frac{1}{8^{4n-2}}-\frac{1}{8^{4n}}+...+\frac{1}{8^{98}}-\frac{1}{8^{100}}\)
Tìm M
\(M=\frac{\frac{1}{99}+\frac{2}{98}+\frac{3}{97}+.......+\frac{99}{1}}{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+.......+\frac{1}{100}}\)
Tính M:
\(M=\frac{\frac{1}{99}+\frac{2}{98}+\frac{3}{97}+.....+\frac{99}{1}}{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+......+\frac{1}{100}}\)
Tính M
\(M=\frac{\frac{1}{99}+\frac{2}{98}+\frac{3}{97}+....+\frac{99}{1}}{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+.....+\frac{1}{100}}\)
