M==1+1/2+1/2^2+1/2^3+....+1/2^2016
So sanh M voi 2
cho M =1/1^2+1/2^2+1/3^2+...+1/10^2 so sanh M voi 4/3
\(M=\frac{1}{1^2}+\frac{1}{2^2}+\frac{1}{3^2}+...+\frac{1}{10^2}\)
\(>1+\frac{1}{2.3}+\frac{1}{3.4}+...+\frac{1}{10.11}\)
\(=1+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{10}-\frac{1}{11}\)
\(=1+\frac{1}{2}-\frac{1}{11}\)
\(>1+\frac{1}{2}-\frac{1}{6}=\frac{4}{3}\)
cho M= 1/12+1/22+1/32+....+1/102. hay so sanh M voi 1^1/3
Cho M=1+1/2+1/2^2+...+1/2^2015+1/2^2016. so sanh M voi 2
M = 1 + 1/2 + 1/22 + ... + 1/22015 + 1/22016
=> 2.M = 2 + 1 + 1/2 + ... + 1/22014 + 1/22015
=> 2.M = 3 + 1/2 +...+ 1/22014 + 1/22015
=> 2.M - M = 3 -1 + 1/22016
=> M = 2 + 1/22016
=> M > 2 ( Do 2 + 1/22016 > 2 )
Cho M=\(\frac{1}{1^2}+\frac{1}{2^2}+\frac{1}{3^2}+...+\frac{1}{10^2}\).Hay so sanh M voi \(1\frac{1}{3}\)
hay so sanh m voi 1
M=\(\frac{1}{2!}+\frac{2}{3!}++......+\frac{9}{10!}\)
\(M=\frac{1}{1.2}+\frac{2}{1.2.3}+.....+\frac{9}{1.2.3.....10}\)
\(M=\frac{2-1}{1.2}+\frac{3-1}{1.2.3}+....+\frac{10-1}{1.2......10}\)
\(M=1-\frac{1}{2}+\frac{1}{2}-\frac{1}{6}+....+\frac{10}{1.2.....10}-\frac{1}{1.2.....10}\)
\(M=1-\frac{1}{1.2.3......10}\)
\(M=1-\frac{1}{3628800}\)
Vì \(1=1\)mà \(\frac{1}{3628800}< 1\)nên \(1-\frac{1}{3628800}< 1\)
Vậy \(M< 1\)
So sanh A voi 1:
A=1/2*2 + 1/3*3 + 1/4*4 + .....+1/2011*2011
So sanh B voi 3/4:
B=1/2*2 + 1/3*3 +1/4*4 + ......+1/2011*2011
TINH NHANH
CHO M= 22+22+23+24+...+21975
HAY SO SANH M VOI 21975
CHO B =1+2+22+23+...+22005
A =22006-1
HAY SO SANH A VOI B
so sanh : 1/2 + 1/2^2 + 1/2^3 + 1/2^2011 voi 1 - 1/2^2010
A=(1/2^2-1) * (1/3^2-1) *...*(1/100^2-1) so sanh A voi 2
so sanh A voi 1/2 nhe, khong phai A voi 2 dau