Ta có:
1/1^2 + 1/3^2 + 1/4^2 + ...+ 1/2016^2
= 1/2.2 + 1/3.3 + 1/4.4 + ... + 1/2016.2016
S < 1/1.2 + 1/2.3 + 1/3.4 + ... + 1/2015.2016
S < 1 - 1/2 + 1/2 - 1/3 + 1/3 - 1/4 + ... + 1/2015 - 1/2016
S < 1 - 1/2016
Mà 1 - 1/2016 < 1
=> S < 1
Vậy A < 1
Ủng hộ nha nhà mk nghèo lắm
cho a=1=1\2+1\3-1\4+1\5...+1\49-1\50.Chung to rang 7\12<4<5\6
Cho S1= 1; S2= 2+3; S3=4+5+6; .... Tính S2016.
CHO S= 1/2+(1/2)^2+(1/2)^3+(1/2)^4+...+(1/2)^2016+(1/2)^2017.CHỨNG MINH S<1
chung minh rang:
\(S=\frac{1}{5^2}-\frac{1}{5^4}+\frac{1}{5^6}-...+\frac{1}{5^{4n-2}}-\frac{1}{5^{4n}}+...+\frac{1}{5^{2010}}-\frac{1}{5^{^{2012}}}
cho S=1-1/2+1/3-1/4+......+1/2015-1/2016+1/2017 và P=1/1009+1/1010+.....+1/2016+1/2017
Tính (S-P)^2016
Cho S=(1+1 phần 2)+(1+2 phần 2 mũ 2)+(1+3 phần 2 mũ 3)+...+(1+2014 phàn 2 mũ 2014)
CMR S<2016
cho s=1/31+1/32+1/33+...+1/59+1/60
chung minh rang : 3/5<s<4/5
S=(1+1/2)+(1+2/2^2)+(1+3/2^3)+...+(1+2014/2^2014)
CM :S<2016
\(\frac{1}{1^2+2^2}+\frac{1}{2^2+3^2}+\frac{1}{3^2+4^2}+.....+\frac{1}{10^2+11^2}< \frac{9}{20}\)
