chung minh rag: a,1/2+1/2^2+1/2^3+,....+1/2^2016 <1 b,1.3.5.7.....39/21.22.23.....40=1/2^20 c,1.3.5.....(2n-1)/(n+1)(n+2)(n+3).....2n=1/2n
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
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
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
chung minh 1/2!+2/3!+3/4!+...+2015/2016!<1
A=1+2+2^2+2^3+.....+2^2016
chung minh rang A chia het cho 3
A=2^2017-1
cho kết quả rùi
tự làm đi
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