\(A=\dfrac{1}{2^2}+\dfrac{1}{2^3}+\dfrac{1}{3^2}+\dfrac{1}{4^2}+...+\dfrac{1}{50^2}\)
\(A=\dfrac{1}{2\cdot2}+\dfrac{1}{2\cdot3}+\dfrac{1}{3\cdot3}+\dfrac{1}{4\cdot4}+...+\dfrac{1}{50\cdot50}\)
\(A=\dfrac{1}{2}-\dfrac{1}{2}+\dfrac{1}{3}-\dfrac{1}{3}+\dfrac{1}{4}-\dfrac{1}{4}+...+\dfrac{1}{50}-\dfrac{1}{50}\)
\(A=1\)
Vậy A=1
Cho A = 1/3 mũ 2 +1/4 mũ 2 +...+1/50 mũ 2. Chứng minh rằng 1/4 < A < 4
Cho A=1/1^1+1/2^2+1/3^2+1/4^2+......+1/50^2. Chứng minh A<2.
Cho A=1/2^2+1/3^2+...+1/50^2.Chứng minh rằng a>1/4
Cho A = 2 1 1 + 2 2 1 + 2 3 1 + 2 4 1 +…+ 2 50 1 . chứng minh A< 2
Cho A=1/1^2+1/2^2+1/3^2+1/4^2+...+1/50^2. Chứng minh A<2
cho A= 1/1+1/2+1/3+1/4+.....+1/50
Chứng minh A nhỏ hơn 2
cho A=1/1^2+1/2^2+1/3^2+1/4^2+...+1/50^2
chứng minh A<2
Cho:
A=1/1^2+1/2^2+1/3^2+1/4^2+....+1/50^2
Chứng minh A>2
Cho
A = 1/1^2+1/2^2+1/3^2+1/4^2+..+1/50^2
Chứng minh A < 2.
