so sanh : 1+2^1+2^2+2^3+.....+2^2016 va 2^2017
So sanh A va B biet
A=2017^100/1+2017+2017^2+2017^3+.....+2017^100
B=2016^100/1+2016+2016^2+2016^3+.....+2016^100
so sanh A va B
A=2017^100 / 1+2017+2017^2+2017^3+...+2017^100
B=2016^100 / 1+2016+2016^2+2016^3+...+2016^100
so sanh A va B
\(A=\frac{2017^{100}}{1+2017+2017^2+2017^3+...+2017^{100}}\)
\(B=\frac{2016^{100}}{1+2016+2016^2+2016^3+...+2016^{100}}\)
Ta có: \(A=\frac{2017^{100}}{1+2017+2017^2+2017^3+...+2017^{100}}\)
\(\Leftrightarrow A=\frac{\left[\left(20.100\right)+16+1\right]^{100}}{1+2017+2017^2+2017^3+...+2017^{10}}\)
\(B=\frac{2016^{100}}{1+2016+2016^2+2016^3+...+2016^{100}}\)
\(\Leftrightarrow B=\frac{\left[\left(20.100+16\right)\right]^{100}}{1+2016+2016^2+2016^3+...+2016^{100}}\)
Ta có hai tổng A và B mới để so sánh:
\(A=\frac{\left[\left(20.100\right)+16+1\right]^{100}}{1+2017+2017^2+2017^3+...+2017^{100}}\)
\(B=\frac{\left[\left(20.100\right)+16\right]^{100}}{1+2016+2016^2+2016^3+...+2016^{100}}\)
Tới đây đơn giản rồi. Bạn làm tiếp đi nhé! Mẹ mình bắt tắt máy không cho làm nên đành dừng lại ở đây thôi! Thông cảm :V
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 tong T=2/2^1+3/2^2+4/2^3 +...+2016/2^2015+2017/2^2016.So sanh T voi 3
chungminh rang ( 7 ^0 + 7^1+7^2+7^3+..........+7^2016+7^2017
so sanh 3^500 va 5^300
Ta có: \(3^{500}=\left(3^5\right)^{100}=243^{100}\)
\(5^{300}=\left(5^3\right)^{100}=125^{100}\)
Vì \(243^{100}>125^{100}\) nên \(3^{500}>5^{300}\)
Vậy \(3^{500}>5^{300}\)
so sanh
A = 2016^2 va B = 2017 . 2015
So sanh A =1/2^0+2/2^1+3/2^2+...+2017/2^2016 và B=4
Cho tong T=2/2^1+3/2^2+4/2^3 +...+2016/2^2015+2017/2^2016.So sanh T voi 3
ai trả lời được mình tik 3 nick luôn
Ta có :
\(T=\frac{2}{2^1}+\frac{3}{2^2}+\frac{4}{2^3}+...+\frac{2016}{2^{2015}}+\frac{2017}{2^{2016}}\)
\(T=1+\frac{3}{1.2^2}+\frac{4}{2.2^2}+\frac{5}{2^2.2^2}+...+\frac{2016}{2^{2013}.2^2}+\frac{2017}{2^{1014}.2^2}\)
\(=1+\frac{1}{2^2}.\left(3+2+\frac{5}{4}+\frac{6}{8}+...+\frac{2016}{x}+\frac{2017}{x}\right)\)
\(=1+\frac{1}{2^2}.\left(3+2+\frac{5}{2^2}+\frac{6}{2^3}+...+\frac{2016}{2^{2013}}+\frac{2017}{2^{2014}}\right)\)
Đến chỗ này chịu!
Ta có
\(T=1+\frac{3}{1\cdot2^2}+\frac{4}{2\cdot2^2}+...+\frac{2017}{2^2\cdot2^{2014}}\)
\(T=1+\frac{1}{2^2}\cdot\left(3+2+\frac{5}{2^2}+\frac{6}{2^3}+...+\frac{2016}{2^{2014}}+\frac{2017}{2^{2015}}\right)\)