Các câu hỏi tương tự
Cho \(A=1-\frac{1}{2}+\frac{1}{3}-\frac{1}{4}+\frac{1}{5}-\frac{1}{6}+...+\frac{1}{49}-\frac{1}{50}\)\(\frac{1}{50}\)
Hãy chứng tỏ rằng \(\frac{7}{12}< A< \frac{5}{6}\)
CHO \(A=1-\frac{1}{2}+\frac{1}{3}-\frac{1}{4}+\frac{1}{5}-\frac{1}{6}+...+\frac{1}{49}-\frac{1}{50}\)\(\frac{1}{50}\)
HÃY CHỨNG Ỏ RẰNG: \(\frac{7}{12}< A< \frac{5}{6}\)
HỘ MÌNH VỚI MÌNH CẦN GẮP:33
Cho A =\(\frac{1}{1.2}+\frac{1}{3.4}+\frac{1}{5.6}+...+\frac{1}{49.50}\)
B=\(\frac{1}{1}+\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{49}+\frac{1}{50}\)
C=\(\frac{1}{2}+\frac{1}{4}+\frac{1}{6}+...+\frac{1}{49}+\frac{1}{50}\)
Chứng minh A = B - 2C
\(cho:A=1-\frac{1}{2}+\frac{1}{3}-\frac{1}{4}+\frac{1}{5}-\frac{1}{6}+...+\frac{1}{49}-\frac{1}{50}\)
\(CMR:\frac{7}{12}< A< \frac{5}{6}\)
Chứng minh rằng : \(\frac{1}{6}< \frac{1}{5^2}+\frac{1}{6^2}+\frac{1}{7^2}+...+\frac{1}{100^2}< \frac{1}{4}\)
Chứng minh rằng : \(\frac{1}{1.2}+\frac{1}{3.4}+\frac{1}{5.6}+...+\frac{1}{49.50}=\frac{1}{26}+\frac{1}{27}+\frac{1}{28}+...+\frac{1}{50}\)
Cho \(A=\frac{1}{1.2}+\frac{1}{3.4}+...+\frac{1}{49.50}\)
\(B=\frac{1}{1}+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{49}+\frac{1}{50}\)
\(C=\frac{1}{2}+\frac{1}{4}+\frac{1}{6}+...+\frac{1}{48}+\frac{1}{50}\)
Chứng minh rằng A=B-2C
Cho \(A=\frac{1}{1.2}+\frac{1}{3.4}+...+\frac{1}{49.50}\)
\(B=\frac{1}{1}+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{49}+\frac{1}{50}\)
\(C=\frac{1}{2}+\frac{1}{4}+\frac{1}{6}+...+\frac{1}{48}+\frac{1}{50}\)
Chứng minh rằng A=B-2C
Cho biểu thức
\(M=\frac{1}{5}+\left(\frac{1}{5}\right)^2+\left(\frac{1}{5}\right)^3+...+\left(\frac{1}{5}\right)^{49}+\left(\frac{1}{5}\right)^{50}\)
chứng minh rằng \(M< \frac{1}{4}\)
Chứng minh rằng :
\(\frac{1}{1\cdot2}+\frac{1}{3\cdot4}+\frac{1}{5\cdot6}+...+\frac{1}{49\cdot50}=\frac{1}{26}+\frac{1}{27}+\frac{1}{28}+...+\frac{1}{50}\)