\(A=1\cdot\dfrac{2}{2}\cdot\dfrac{3}{3}\cdot...\cdot\dfrac{99}{99}\cdot\dfrac{1}{100}=\dfrac{1}{100}\)
\(A=1\cdot\dfrac{2}{2}\cdot\dfrac{3}{3}\cdot...\cdot\dfrac{99}{99}\cdot\dfrac{1}{100}=\dfrac{1}{100}\)
Tính A=1/2 x 2/3 x 3/4 x ...x 99/100
Cho A=9/1×2+9/2×3+9/3×4+...+9/98×99+9/99×100
Cho A =1/2^2+1/3^2+1/4^2+.....+1/99^2+1/100^2
1-2+3-4+5-6+...+99-100
1. Chứng minh:
\(\dfrac{1}{3}-\dfrac{2}{3^2}+\dfrac{3}{3^3}-\dfrac{4}{3^4}+...+\dfrac{99}{3^{99}}-\dfrac{100}{3^{100}}< \dfrac{3}{16}\)
2. Cho:
\(M=\dfrac{1}{15}+\dfrac{1}{105}+\dfrac{1}{315}+...+\dfrac{1}{1977}\). So sánh M với 12.
3, Chứng tỏ :
\(B=\dfrac{1}{2!}+\dfrac{2}{3!}+\dfrac{3}{4!}+...+\dfrac{99}{100!}< 1\)
Cho số A = 3 + \(3^2+3^3+3^4+...+3^{98^{ }}+3^{99}+3^{100}\)
Chứng minh rằng A : 121
Cho M = \(\dfrac{\dfrac{1}{99}+\dfrac{2}{98}+\dfrac{3}{97}+..........+\dfrac{99}{1}}{\dfrac{1}{2}+\dfrac{1}{3}+\dfrac{1}{4}+..........+\dfrac{1}{100}}\) ; N = \(\dfrac{92-\dfrac{1}{9}-\dfrac{2}{10}-\dfrac{3}{11}-.........-\dfrac{92}{100}}{\dfrac{1}{45}+\dfrac{1}{50}+\dfrac{1}{55}+......+\dfrac{1}{500}}\)
Tìm tỉ số phần trăm của M và N
a, \(\left(1+\dfrac{1}{2}\right)\left(1+\dfrac{1}{2^2}\right)\left(1+\dfrac{1}{2^3}\right)\left(1+\dfrac{1}{2^4}\right)....\left(1+\dfrac{1}{2^{50}}\right)< 3\)
b, \(\dfrac{1}{2}-\dfrac{1}{2^2}+.........+\dfrac{1}{2^{99}}-\dfrac{1}{2^{100}}< \dfrac{1}{3}\)