2017/2016va 2018/2016 so sanh dau do la phan so
Tính :
S1= 1-2+3-4+....................+2017-2018
S2= 1-4+7-10+..............+2015-2018
S3= 1+2-3-4+.....................+2015+2016-2017-2018
Giup minh voi minh dang can gap nha
ai nhanh ma dungthi minh tich cho nha
So sánh A và B biết:
A=2016/2017+2017/2018+2018/2016
B=1/3+1/4+1/5+...+1/17
1) CMR:
\(\frac{1}{3^2}+\frac{1}{4^2}+\frac{1}{5^2}+\frac{1}{6^2}+...+\frac{1}{100^2}< \frac{1}{2}\)Ai nhanh mk tick
2) So sánh 2 số:
\(A=\frac{5^{2018}-2016}{5^{2018}-2017}\)\(Với\)\(B=\frac{5^{2018}-2018}{5^{2018}-2019}\)
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
S = 1 x 2 x 3 x 4 + 2 x 3 x 4 x 5 + ... + 2015 x 2016 x 2017 x 2018
1+2+3+4+...+2016+2017+2018
1+2+3+4+...+2016+2017+2018
cho A =1+2^2018+3^2017+4^2016+...+2018^2+2019,B=1+2^2017+3^2016+...+2017^2+2018,chứng tỏ giá trị biểu thức A-3B dương
So sanh 2016 /2017+2017/2018 voi 1