a,A=1/1^2+1/2^2+1/3^2+1/4^2+...+1/50^2.chung minh rang a<2
b;2^1+2^2+2^3+...+2^30.chung minh rang B chia het cho21
Chung minh A < 2:
A=1/1^2+1/2^2+1/3^2+1/4^2+.....+1/50^2
Chung minh
A=1/2+1/2^2+15/2^3+....+1/2^50<1
ChoA=1/1^2+1/2^2+1/3^2+1/4^2+...+1/50^2
Chung minh A <2
Cho A = 1/3^2 + 1/4^2 + 1/5^2 +...+ 1/50^2
Chung minh 1/4 < A < 4/9
Cho A=1+1/2+1/3+...+1/2^100-1
chung minh rang:
a,A<100
b,A>50
CHO A=\(\frac{1}{1^2}+\frac{1}{2^2}+\frac{1}{3^2}+....+\frac{1}{50^2}\)
CHUNG MINH RANG A<2
cho A=\(\frac{1}{1^2}+\frac{1}{2^2}+\frac{1}{3^2}+\frac{1}{4^2}+.....+\frac{1}{50^2}\)
Chung minh rang A<2
Cho mik hoi nha, ai nhanh va dung mik se tick.
\(A=\frac{1}{1^2}+\frac{1}{2^2}+\frac{1}{3^2}+...+\frac{1}{50^2}\)
Chung minh A<2
Cam on nha