Cho:B=1/2^2+1/3^2+1/4^2+...........+1/2016^2 chung minh B>1/2
Chung minh rang: B=1 + 1/2 + 1/3 + 1/4 +1/5 + .....+ 1/22016 - 2 + 1/22016 - 1 > 1008
chung minh 1/2!+2/3!+3/4!+...+2015/2016!<1
2. Cho:
B= 1 - 1/2 + 1/3 - 1/4 +...+ 1/2021 - 1/2022 + 1/2023 C= 1/1012 + 1/1013 + 1/1014 +...+ 1/2021 + 1/2022 + 1/2023
Tính: B-C
Cho A=1/2!+2/3!+3/4!+...+2015/2016!
Chung minh :A<1
Cho A=1/2!+2/3!+3/4!+...+2015/2016!
Chung minh :A<1
a. So sanh 2 phan so:A= 2015/2016+2016/2017+2017/2018 va B = 2015+2016+2017/2016+2017+2018
b.1/2.4+1/4.6+........+1/(2x-2).2x = 1/8
c.Cho A = 1/4+1/9+1/16+...+1/81+1/100 . Chung minh rang : A > 65/132
d.Cho B = 12/(2 . 4 ) ^ 2 + 20/ (4 . 6) ^2 + ...........+ 388/ ( 96 . 98 ) ^ 2 + 396/ ( 98 . 100 ) ^2 .Hay so sanh B voi 1 /4
Cho A= 1/22+1/32+1/42+...+1/20152+1/20162
Chung minh A ko phai stn
Ta có: \(A=\frac{1}{2^2}+\frac{1}{3^2}+\frac{1}{4^2}+....+\frac{1}{2016^2}< \frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+....+\frac{1}{2015.2016}\)
\(=1-\frac{1}{2016}=\frac{2015}{2016}\)
Mà \(A< \frac{2015}{2016}\)
Nên A không phải là 1 số tự nhiên
Cho A=1/2!+2/3!+3/4!+...+2015/2016!
Chung minh :A<1
cach lam day du thi minh se tick
Cho A=1/2!+2/3!+3/4!+...+2015/2016!
Chung minh :A<1
cach lam day du thi minh se tick