\(A=\frac{1}{2^2}+\frac{1}{2^4}+\frac{1}{2^6}+\frac{1}{2^8}+...+\frac{1}{2^{100}}\)
\(4A=1+\frac{1}{2^2}+\frac{1}{2^4}+\frac{1}{2^6}+...+\frac{1}{2^{98}}\)
\(3A=4A-A=1-\frac{1}{2^{100}}<1\)
\(A<\frac{1}{3}\)
Cho A= 1/2^2+ 1/2^4+ 1/2^6+ 1/2^8+...1/2^100. Chứng minh A< 1/3
Cho A=1/2^2+1/2^4+1/2^6+1/2^8+...+1/2^100
Chứng minh rằng A<1/3
cho A=1/2^2+1/2^4+1/2^6+...+1/2^100
chứng minh A<1/3
Cho A=\(\frac{1}{2^2}+\frac{1}{2^4}+\frac{1}{2^6}+\frac{1}{2^8}+...+\frac{1}{2^{100}}\). Chứng minh A<\(\frac{1}{3}\)
A=1/2^2 +1/3^2+1/4^2+...+1/100^2 và B=1/4^2+1/6^2+1/8^2+...+1/200^2. Tính A/B
giup dum minh like cho gap lam roi
1/ Cho A= \(\dfrac{1}{3}\)-\(\dfrac{2}{3^2}\)+\(\dfrac{3}{3^3}\)-\(\dfrac{4}{3^4}\)+.....+\(\dfrac{99}{3^{99}}\)-\(\dfrac{100}{3^{100}}\) Chứng minh A < \(\dfrac{3}{16}\)
2/ Cho B=(\(\dfrac{1}{2^2}\)-1)(\(\dfrac{1}{3^2}\)-1)....(\(\dfrac{1}{100^2}\)-1) So sánh B và \(\dfrac{-1}{2}\)
a)Chứng minh rằng :1/6<1/5^2+1/6^2+1/7^2+...+1/100^2<1/4
b)tính tổng :(-3)^0+(-3)^1+(-3)^2+...+(-3)^20
Cho biểu thức A=\(\dfrac{1}{2^2}\)+\(\dfrac{1}{3^2}\)+\(\dfrac{1}{4^2}\)+\(\dfrac{1}{5^2}\)+\(\dfrac{1}{6^2}\)+\(\dfrac{1}{7^2}\)+\(\dfrac{1}{8^2}\)+\(\dfrac{1}{9^2}\)+\(\dfrac{1}{10^2}\)
Chứng minh rằng A<1
Cho \(A=\frac{1}{2^2}+\frac{1}{2^4}+\frac{1}{2^6}+...+\frac{1}{2^{100}}\)
Chứng minh rằng \(A< \frac{1}{3}\)
