Các câu hỏi tương tự
Cho A = 1 + 1/2 = 1/3 + 1/4 + ... + 1/2^100 -1
CMR : a) A < 100
b) A > 50
cho A = 1/3 mũ 2 + 1/4 mũ 2 + 1/5 mũ 2 + ...+ 1/50 mũ 2 CMR : A > 1/4
giúp mình nhé
cho A = 1/3 mũ 2 + 1/4 mũ 2 + 1/5 mũ 2 + ...+ 1/50 mũ 2 CMR : A1/4
cho A=1+1/2+1/3+1/4+....................+1/2^100-1 , cmr
a. A<100 , b.A>50
CMR: A=1+1/2^2+1/3^2+1/4^2+...+1/50^2>2
Bài 1 : Cho A = \(\frac{1}{^{1^2}}+\frac{1}{2^2}+\frac{1}{3^2}+\frac{1}{4^2}+...+\frac{1}{50^2}\) . CMR : A < 2
Bài 2 : Cho B = \(2^1+2^2+2^3+2^4+...+2^{30}\). CMR : B chia hết cho 21
bài 6:
cho : A= 1/12+1/22+1/32+1/42+...+1/502
CMR: A<2
CMR: 1/26 +1 /27 + ... + 1/50 = 99/50 - 97/50 +...+ 7/4 - 5/3 + 3/2 - 1
CMR
A=1/2+1/3+1/4+1/5+...+1/50 > 2,86