Các câu hỏi tương tự
CMR : \(\frac{1}{6}< \frac{1}{5^2}+\frac{1}{6^2}+\frac{1}{7^2}+...+\frac{1}{100^2}< \frac{1}{4}\)
Tính nhanh:a) frac{3^2}{1.4}+frac{3^2}{4.7}+frac{3^2}{7.10}+frac{3^2}{10.13}+frac{3^2}{13.16}+...+frac{3^2}{97.100}b)frac{1}{10}+frac{1}{40}+frac{1}{88}+frac{1}{154}+frac{1}{238}+frac{1}{940}c) A frac{6}{4}+frac{6}{28}+frac{6}{70}+frac{6}{130}+frac{6}{208}d) M (1-frac{1000}{2016}).(1-frac{1001}{2016}).(1-frac{1002}{2016})...(1-frac{2017}{2016})e) A 8400.(frac{1}{1.5}+frac{1}{5.9}+frac{1}{9.13}+frac{1}{13.17}+frac{1}{17.21}+frac{1}{21.25})f) T (frac{1}{2}+1).(frac{1}{3}+1).(frac{1}{4}+1)...(frac...
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Tính nhanh:
a) \(\frac{3^2}{1.4}+\frac{3^2}{4.7}+\frac{3^2}{7.10}+\frac{3^2}{10.13}+\frac{3^2}{13.16}+...+\frac{3^2}{97.100}\)
b)\(\frac{1}{10}+\frac{1}{40}+\frac{1}{88}+\frac{1}{154}+\frac{1}{238}+\frac{1}{940}\)
c) A= \(\frac{6}{4}+\frac{6}{28}+\frac{6}{70}+\frac{6}{130}+\frac{6}{208}\)
d) M= \((1-\frac{1000}{2016}).(1-\frac{1001}{2016}).(1-\frac{1002}{2016})...(1-\frac{2017}{2016})\)
e) A= \(8400.(\frac{1}{1.5}+\frac{1}{5.9}+\frac{1}{9.13}+\frac{1}{13.17}+\frac{1}{17.21}+\frac{1}{21.25})\)
f) T= \((\frac{1}{2}+1).(\frac{1}{3}+1).(\frac{1}{4}+1)...(\frac{1}{98}+1).(\frac{1}{99}+1)\)
h) A=\(\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+\frac{1}{20}+...+\frac{1}{90}\)phần \(\frac{1}{5}+\frac{5}{3}+\frac{5}{6}+\frac{1}{2}+...+\frac{1}{9}\)
CMR:\(\frac{1}{6}< \frac{1}{5^2}+\frac{1}{6^2}+\frac{1}{7^2}+....+\frac{1}{100^2}\)<\(\frac{1}{4}\)
CMR:
\(\frac{1}{4^2}+\frac{1}{5^2}+\frac{1}{6^2}+..................+\frac{1}{64^2}< \frac{5}{16}\)
CMR : B=\(\frac{1}{2^2}+\frac{1}{3^2}+\frac{1}{4^2}+\frac{1}{5^2}+\frac{1}{6^2}+\frac{1}{7^2}+\frac{1}{8^2}\)> 1
cmr A=\(\frac{1}{5^2}+\frac{1}{6^2}+\frac{1}{7^2}+...+\frac{1}{100^2}< \frac{1}{4}\)
Các bạn giúp với hứa cho 3 tick
CMR: \(\frac{1}{6}< \frac{1}{5^2}+\frac{1}{6^2}+\frac{1}{7^2}+...+\frac{1}{100^2}< \frac{1}{4}\)
CMR:
\(\frac{1}{3^2}+\frac{1}{6^2}+\frac{1}{9^2}+...+\frac{1}{2013^2}< \frac{1}{5}\)
CMR: \(\frac{1}{2^2}+\frac{1}{3^2}+\frac{1}{4^2}+\frac{1}{5^2}+\frac{1}{6^2}+\frac{1}{7^2}+\frac{1}{8^2}