Tính :
1) C = \(\left(\dfrac{1}{200^2}-1\right)\left(\dfrac{1}{199^2}-1\right)...\left(\dfrac{1}{101^2}-1\right)\)
2) \(D=\dfrac{1}{1-\dfrac{1}{1-2^{-1}}}+\dfrac{1}{1+\dfrac{1}{1+2^{-1}}}\)
Tính giá trị biểu thức A , biết rằng A = M : N
Mà M = \(\dfrac{\dfrac{1}{99}+\dfrac{2}{98}+\dfrac{3}{97}+\dfrac{4}{96}+...+\dfrac{97}{3}+\dfrac{98}{2}+\dfrac{99}{1}}{\dfrac{1}{2}+\dfrac{1}{3}+\dfrac{1}{4}+\dfrac{1}{5}+\dfrac{1}{6}+...+\dfrac{1}{100}}\)
N = \(\dfrac{92-\dfrac{1}{9}-\dfrac{2}{10}-\dfrac{3}{11}-...-\dfrac{90}{98}-\dfrac{91}{99}-\dfrac{92}{100}}{\dfrac{1}{45}+\dfrac{1}{50}+\dfrac{1}{55}+...+\dfrac{1}{495}+\dfrac{1}{500}}\)
Cho \(A=\dfrac{1}{2^2}+\dfrac{1}{3^2}+\dfrac{1}{4^2}+...+\dfrac{1}{100^2}\) và \(B=\dfrac{1}{4^2}+\dfrac{1}{6^2}+\dfrac{1}{8^2}+...+\dfrac{1}{200^2}\). Khi đó \(\dfrac{A}{B}=...\)
Tính :
1, A = \(\dfrac{1}{2}+\dfrac{1}{3}+\dfrac{1}{4}+........+\dfrac{1}{100}\)
2, B = \(\dfrac{1}{2}+\dfrac{2}{3}+\dfrac{3}{4}+.........+\dfrac{99}{100}\)
Tính :
A = \(\dfrac{1}{2}-\dfrac{1}{2^2}+\dfrac{1}{2^3}-\dfrac{1}{2^4}+......+\)\(\dfrac{1}{2^99}-\)\(\dfrac{1}{2^100}\)
Cho C=\(\dfrac{1}{2}\cdot\dfrac{3}{4}\cdot\dfrac{5}{6}\cdot\cdot\cdot\dfrac{199}{200}\) Chứng minh C2<\(\dfrac{1}{201}\)
B = \(\dfrac{1}{2}-\dfrac{1}{2^2}+\dfrac{1}{2^3}-\dfrac{1}{2^4}+..........+\dfrac{1}{2^99}-\dfrac{1}{2^100}\)
\(\dfrac{\left(13\dfrac{1}{4}-2\dfrac{5}{27}-10\dfrac{5}{6}\right).230\dfrac{1}{25}+46\dfrac{3}{4}}{\left(1\dfrac{3}{10}+\dfrac{10}{3}\right):\left(12\dfrac{1}{3}-14\dfrac{2}{7}\right)}\)
\(\dfrac{\left(1+2+3+...+99+100\right)\left(\dfrac{1}{2}-\dfrac{1}{3}-\dfrac{1}{7}-\dfrac{1}{9}\right)\left(63.1,2-21.3,6\right)}{1-2+3-4+.....+99-100}\)
1.Tìm GTLN của biểu thức :
\(\dfrac{a^{2012}+2013}{a^{2012}+2011}\)
2.Cho \(B=\dfrac{1}{2}\cdot\dfrac{3}{4}\cdot\dfrac{5}{6}\cdot\cdot\cdot\dfrac{99}{100}\)
CM : \(\dfrac{1}{15}< B< \dfrac{1}{10}\)
Làm giúp mk nha chìu mai học r !!!