\(G< \frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+...+\frac{1}{199.200}\)
\(G< \frac{1-1}{1.2}+\frac{3-2}{2.3}+\frac{4-3}{3.4}+...+\frac{200-199}{199.200}\)
\(G< 1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{199}-\frac{1}{200}\)
\(G< 1-\frac{1}{200}< 1\)
a) Cho A=\(\frac{1}{2^2}+\frac{1}{3^2}+\frac{1}{4^2}+...+\frac{1}{2015^2}.\) Chứng minh rằng: A < 1
b) Cho B= \(2^1+2^2+2^3+...+2^{2016}\) Chứng minh rằng: B chia hết cho 21
Cho A = \(\frac{1}{101}+\frac{1}{102}+\frac{1}{103}+...+\frac{1}{200}\)
Chứng minh rằng A < \(1\)
Chứng minh rằng: \(\frac{1}{2\times2}+\frac{1}{3\times3}+\frac{1}{4\times4}+....+\frac{1}{19\times19}+\frac{1}{20\times20}
Cho A=\(\frac{1}{101}\)+\(\frac{1}{102}\)+\(\frac{1}{103}\)+ . . . . . . . .+\(\frac{1}{199}\)+\(\frac{1}{200}\)
a)chứng tỏ rằng A<\(\frac{3}{4}\)(tách 2 dòng)
chứng tỏ rằng A >\(\frac{7}{12}\)(tách 2 dòng)
chứng tỏ rằng A >\(\frac{5}{8}\)(tách 4 dòng)
Cho M= \(\frac{1}{1!}\)+ \(\frac{1}{2!}\)+ \(\frac{1}{3!}\)+ ... + \(\frac{1}{100!}\)
Chứng minh rằng: 3! -M > 4
Chứng minh rằng \(\frac{1}{3}+\frac{1}{7}+\frac{1}{13}+\frac{1}{21}+\frac{1}{31}+\frac{1}{43}+\frac{1}{57}+\frac{1}{73}+\frac{1}{91}< 1\)
Chứng minh rằng : \(\frac{1}{3}+\frac{1}{7}+\frac{1}{13}+\frac{1}{21}+\frac{1}{31}+\frac{4}{43}+\frac{1}{57}+\frac{1}{73}+\frac{1}{91}<1\)
( lời giải chi tiết nha , mình đang cần gấp )
Chứng minh : \(\frac{1}{1}-\frac{1}{1}+\frac{1}{2}-\frac{1}{3}+\frac{1}{5}-\frac{1}{8}+\frac{1}{13}-\frac{1}{21}+\frac{1}{34}-\frac{1}{55}+...< \frac{3}{10}\).
\(\frac{\left(\frac{1}{1}+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{101}\right)-\left(\frac{1}{300}+\frac{1}{301}+\frac{1}{302}+...+\frac{1}{400}\right)}{\left(\frac{1}{1}+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{299}\right)-\left(\frac{1}{102}+\frac{1}{103}+\frac{1}{104}+...+\frac{1}{400}\right)}\)
G mk với, mk cần gấp lắm. Ai giải được mk k cho
