So sánh \(A=\frac{2014}{\sqrt{2015}}+\frac{2015}{\sqrt{2014}}\) và \(B=\sqrt{2014}+\sqrt{2015}\)
không dùng máy tính hãy so sánh: \(\frac{2014}{\sqrt{2015}}+\frac{2015}{\sqrt{2014}}và\sqrt{2014}+\sqrt{2015}\)
Có Ta có\(VT=\frac{2014}{\sqrt{2015}}+\frac{2015}{\sqrt{2014}}=\frac{2015-1}{\sqrt{2015}}+\frac{2014+1}{\sqrt{2014}}=\sqrt{2015}-\frac{1}{\sqrt{2015}}+\sqrt{2014}+\frac{1}{\sqrt{2014}}.\)\(20140\Leftrightarrow VT>VP\)
So sánh 2 số:
\(a)\sqrt{2014}-\sqrt{2013};B=\sqrt{2015}-\sqrt{2014}\\ b)E=\frac{2014}{\sqrt{2015}}+\frac{2015}{\sqrt{2014}};F=\sqrt{2014}+\sqrt{2015}\)
không dùng máy tính hãy so sánh\(\frac{2014}{\sqrt{2015}}+\frac{2015}{\sqrt{2014}}\) với \(\sqrt{2014}+\sqrt{2015}\)
\(\frac{2014}{\sqrt{2015}}+\frac{2015}{\sqrt{2014}}=\frac{2015-1}{\sqrt{2015}}+\frac{2014+1}{\sqrt{2014}}\)
= \(\sqrt{2014}+\sqrt{2015}+\frac{1}{\sqrt{2014}}-\frac{1}{\sqrt{2015}}>\sqrt{2014}+\sqrt{2015}\)
So sánh A và B:
\(A=\sqrt{2015^2-1}-\sqrt{2014^2-1}\)
\(B=\frac{2.2014}{\sqrt{2015^2-1}+\sqrt{2014^2-1}}\)
So sánh
a, \(\frac{2014}{\sqrt{2015}}\) + \(\frac{2015}{\sqrt{2014}}\) và. \(\sqrt{2014}\) + \(\sqrt{2015}\)
b, \(\frac{9}{\sqrt{11}-\sqrt{2}}\) và \(\frac{6}{3-\sqrt{3}}\)
Cho M=\(\frac{\sqrt{2}-\sqrt{1}}{1+1}+\frac{\sqrt{3}-\sqrt{2}}{2+3}+\frac{\sqrt{4}-\sqrt{3}}{3+4}+...+\frac{\sqrt{2015}-\sqrt{2014}}{2014+2015}\)
Hãy so sánh M với 1/2
a/Tính: A= \(\sqrt{1+2006^2+\frac{2006^2}{2007^2}}+\frac{2006}{2007}\)
b/Cho A=\(\sqrt{2015^2-1}-\sqrt{2014^2-1}\)và B=\(\frac{2.2014}{\sqrt{2015^2-1}+\sqrt{2014^2-1}}\)
So sánh A vs B
Chứng minh \(\frac{2014}{\sqrt{2015}}+\frac{2015}{\sqrt{2014}}>\sqrt{2014}+\sqrt{2015}\)
\(VT=\frac{2015-1}{\sqrt{2015}}+\frac{2014+1}{\sqrt{2014}}=\sqrt{2015}-\frac{1}{\sqrt{2015}}+\sqrt{2014}+\frac{1}{\sqrt{2014}}\)
\(>\sqrt{2014}+\sqrt{2015}\)(do \(\frac{1}{\sqrt{2014}}-\frac{1}{\sqrt{2015}}>0\))
Ban kia lam dung roi do
k tui nha
thanks
so sánh \(\sqrt{2015^2-1}-\sqrt{2014^2-1}\) và \(\frac{2.2014}{\sqrt{2015^2-1}+\sqrt{2014^2-1}}\)
Nhân cả 2 với (\(\sqrt{2015^2-1}\)+\(\sqrt{2014^2-1}\))
A = 2015^2 -1 -2014^2 + 1 = (2014 + 1)^2 -2014^2 = 2.2014 + 1
B = 2.2014
=> A = B + 1