So Sanh : \(A=\frac{2014^{2013}+1}{2014^{2014}+1}\) va \(B=\frac{2014^{2012}+1}{2014^{2013}+1}\)
Giup minh voi nha, Thanks you cac ban
So sanh: \(A=\frac{2014^{2013}+1}{2014^{2014}+1}\) va \(B+\frac{2014^{2012}+1}{2014^{2013}+1}\)
Giup minh nha, thanks cac ban
\(A=\frac{2014^{2013}+1}{2014^{2014}+1}<\frac{2014^{2013}+1+2013}{2014^{2014}+1+2013}\)
\(=\frac{2014\left(2014^{2012}+1\right)}{2014\left(2014^{2013}+1\right)}\)
\(=\frac{2014^{2012}+1}{2014^{2013}+1}\)\(=B\)
=> A < B
So sánh ;A=2014^2013+1/2014^2013-1 va B=2014^2013-1/2014^2013-3.giup mk vs
ta có: \(A=\frac{2014^{2013}+1}{2014^{2013}-1}=\frac{2014^{2013}-1+2}{2014^{2013}-1}=1+\frac{2}{2014^{2013}-1}\)
\(B=\frac{2014^{2013}-1}{2014^{2013}-3}=\frac{2014^{2013}-3+2}{2014^{2013}-3}=1+\frac{2}{2014^{2013}-3}\)
\(\Rightarrow\frac{2}{2014^{2013}-1}< \frac{2}{2014^{2013}-3}\)
\(\Rightarrow1+\frac{2}{2014^{2013}-1}< 1+\frac{2}{2014^{2013}-3}\)
=> A < B
So sánh 2 phân số: A= \(\frac{2014^{2013}+1}{2014^{2014}+1}\)và B= \(\frac{2014^{2012}+1}{2014^{2013}+1}\)
Gợi ý nhé: bạn hãy so sánh 2014A và 2014B rồi suy ngược lại A và B
Ta có:
2014A=20142014+ 2014/20142014+1=1+2013/20142014+1
2014B=20142013+2014/20142013+1=1+2013/20142013+1
vì 1+2013/20142014+1<1+2013/20142013+1 nên 10A < 10B
suy ra A<B
So sánh
\(A=\frac{2014^{2013}+1}{2014^{2013}-13}\)\(B=\frac{2014^{2012}+8}{2014^{2012}-11}\)
\(\frac{2014^{2013}+1}{2014^{2013}-13}\)lớn hơn 1 là \(\frac{14}{2014^{2013}-13}\)
\(\frac{2014^{2012}+8}{2014^{2012}-11}\)lớn hơn 1 là \(\frac{19}{2014^{2012}-11}\)
\(\frac{14}{2014^{2013}-13}\)\(< \)\(\frac{19}{2014^{2012}-11}\)
\(\Rightarrow A< B\)
A=2012/2013+2013/2014, B=2012+2013/2013+2014. So sanh A va B
Ta có: 1- 2012/2013=1/2013
1- 2013/2014=1/2014
Mà 1/2013>1/2014
vậy 2012/2013<2013/2014
\(\frac{2011\text{X}2013+2014}{2012\text{X}2012+2013}\)voi 1
hay so sanh
\(\frac{2011.2013+2014}{2012.2012+2013}=\frac{2011.2013+2013+1}{2012.2012+2012+1}=\frac{2013.\left(2011+1\right)+1}{2012.\left(2012+1\right)+1}=\frac{2013.2012+1}{2012.2013+1}=1\)
Vậy \(\frac{2011.2013+2014}{2012.2012+2013}=1\)
(Dấu . là nhân nha bạn)
\(\frac{2011.2013+2014}{2012.2012+2013}=\frac{2011.2013+2014}{\left(2011+1\right).\left(2013-1\right)+2013}\)
\(=\frac{2011.2013+2014}{2011.\left(2013-1\right)+2013-1+2014}\)
\(=\frac{2011.2013+2014}{2011.2013-2011+2013-1+2014}\)
\(=\frac{2011.2013+2014}{2011.2013+2015}\)
Vì 2011.2013 + 2014 < 2011.2013 + 2015
=> \(\frac{2011.2013+2014}{2011.2013+2015}< 1\)
so sanh :A=2013^2012+1/2013^2013+1 va 2013^2013+1/2013^2014+1
Đặt B = 2013^2013+1/2013^2014+1
Ta có: \(B=\frac{2013^{2013}+1}{2013^{2014}+1}< \frac{2013^{2013}+1+2012}{2013^{2014}+1+2012}=\frac{2013^{2013}+2013}{2013^{2014}+2013}=\frac{2013\left(2013^{2012}+1\right)}{2013\left(2013^{2013}+1\right)}=\frac{2013^{2012}+1}{2013^{2013}+1}=A\)
Vậy A > B
So sánh hai phân số : A= \(\frac{2014^{2014}+1}{2014^{2013}+1}\) và B= \(\frac{2014^{2013}+1}{2014^{2012}+1}\)
Mình giải như thế này (giải theo công thức) :
Ta thấy A > 1
A=\(\frac{2014^{2014}+1}{2014^{2013}+1}\)> \(\frac{2014^{2014}+1+2013}{2014^{2013}+1+2013}\)= \(\frac{2014^{2014}+2014}{2014^{2013}+2014}\)= \(\frac{2014.\left(2014^{2013}+1\right)}{2014.\left(2014^{2012}+1\right)}=\frac{2014^{2013}+1}{2014^{2012}+1}\)
Vậy A>B
\(\frac{\frac{1}{2}+\frac{1}{3}+......+\frac{1}{2013}}{\frac{2012}{1}+\frac{2012}{2}+\frac{2011}{3}+...+\frac{1}{2013}}\)
=\(\frac{\frac{1}{2}+\frac{1}{3}+..+\frac{1}{2013}}{\frac{2012}{1}+2+\frac{2012}{2}+1+\frac{2011}{3}+1+...+\frac{1}{2013}+1-2014}\)
=\(\frac{\frac{1}{2}+\frac{1}{3}+...+\frac{1}{2013}}{\frac{2014}{1}+\frac{2014}{2}+...+\frac{2014}{2013}-2014}\)
=\(\frac{\frac{1}{2}+\frac{1}{3}+...+\frac{1}{2013}}{2014\left(1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{2013}-1\right)}\)
=\(\frac{1}{2014}\)