mk cm vế sau, vế đầu tương tự nha:
ta có:
1/2<2/3
3/4<4/5
...
99/100<100/101
=>A^2<1/2×2/3×3/4×...×99/100×100/101
=>A^2<1/101<1/100
=>A<1/10(dpcm)
Cho A=\(\frac{1}{2}.\frac{3}{4}.\frac{5}{6}...\frac{99}{100}\)Chứng minh rằng:\(\frac{1}{15}< A< \frac{1}{10}\)
\(A=\frac{1}{2}.\frac{3}{4}.\frac{5}{6}...\frac{99}{100}\)
Chứng minh 1/15 < A < 1/10
A=\(\frac{1}{2}.\frac{3}{4}.\frac{5}{6}......\frac{97}{98}.\frac{99}{100}\)
Chứng minh 1/15 < A < 1/10
\(A=\frac{1}{2}.\frac{3}{4}.\frac{5}{6}....\frac{99}{100}\)
Chứng minh \(\frac{1}{15}
Cho \(A=\frac{1}{2}.\frac{3}{4}.\frac{5}{6}...\frac{99}{100}\)
Chứng minh rằng 1/15 < A < 1/10
\(A=\frac{1}{2}.\frac{3}{4}.\frac{5}{6}...\frac{99}{100}\)
Chứng minh \(\frac{1}{15}
cho A=\(\frac{1}{2}\cdot\frac{3}{4}\cdot\frac{5}{6}\cdot\cdot\cdot\frac{99}{100}\)
CHỨNG MINH \(\frac{1}{15}< a< \frac{1}{10}\)
Chứng minh rằng
a) \(\frac{1}{5}<\frac{1}{2}-\frac{1}{3}+\frac{1}{4}-\frac{1}{5}+...+\frac{1}{98}-\frac{1}{99}<\frac{2}{5}\)
b) \(\frac{1}{15}<\frac{1}{2}.\frac{3}{4}.\frac{5}{6}...\frac{99}{100}<\frac{1}{10}\)
Cho A = \(\frac{1}{2}\cdot\frac{3}{4}\cdot\frac{5}{6}\cdot...\cdot\frac{99}{100}\)
Chứng minh rằng \(\frac{1}{15}< A< \frac{1}{10}\)
