(a-b)^2>=0
<=>a^2+b^2>=2ab
<=>(a+b)^2>=4ab
<=>a+b>=2Căn(ab)
Cmtt:b+c,c+a
rùi + vào
( a - b ) 2 > = 0
< = > a2 + b2 > = 2ab
< = > (a + b)2 > = 4ab
< = > a + b > =2 \(\sqrt{ab}\)
b + c,c + a ....... tự tính
(a-b)^2>=0
<=>a^2+b^2>=2ab
<=>(a+b)^2>=4ab
<=>a+b>=2Căn(ab)
Cmtt:b+c,c+a
rùi + vào
( a - b ) 2 > = 0
< = > a2 + b2 > = 2ab
< = > (a + b)2 > = 4ab
< = > a + b > =2 \(\sqrt{ab}\)
b + c,c + a ....... tự tính
cho a,b,c>0 thỏa mãn \(a^2+b^2+c^2=1\).CMR
\(\dfrac{\sqrt{ab+2c^2}}{\sqrt{1+ab-c^2}}+\dfrac{\sqrt{bc+2a^2}}{\sqrt{1+bc-a^2}}+\dfrac{\sqrt{ca+2b^2}}{\sqrt{1+ca-b^2}}\ge2+ab+bc+ca\)
cho a,b,c >0 thõa a+b+c=1
cmr \(\frac{bc}{\sqrt{a+bc}}+\frac{ca}{\sqrt{b+ca}}+\frac{ab}{\sqrt{c+ab}}\le\)\(\frac{1}{2}\)
cho a,b,c>0 thỏa mãn: a+b+c=3
CMR: \(\sqrt{a}+\sqrt{b}+\sqrt{c}\ge ab+bc+ca\)
cho a,b,c >0
cmr \(\frac{1}{a^3+b^3+abc}+\frac{1}{b^3+c^3+abc}+\frac{1}{c^3+a^3+abc}\le\frac{1}{abc}\)
cmr \(\frac{\sqrt{ab}}{c+2\sqrt{ab}}+\frac{\sqrt{bc}}{a+2\sqrt{bc}}+\frac{\sqrt{ca}}{b+2\sqrt{ca}}\le1\)
Cho a,b,c>0
CMR:
\(\sqrt{\frac{2}{a}}+\sqrt{\frac{2}{b}}+\sqrt{\frac{2}{c}}\le\sqrt{\frac{a+b}{ab}}+\sqrt{\frac{b+c}{bc}}\sqrt{\frac{c+a}{ca}}\)
cho a,b,c >0
cmr \(\sqrt{\frac{a+b}{c+ab}}+\sqrt{\frac{b+c}{a+bc}}+\sqrt{\frac{c+a}{b+ca}}\ge\)3
Cho a,b,c>0 Cmr
\(\sqrt{\frac{2}{a}}+\sqrt{\frac{2}{b}}+\sqrt{\frac{2}{c}}\le\sqrt{\frac{a+b}{ab}}+\sqrt{\frac{b+c}{bc}}+\sqrt{\frac{c+a}{ca}}\)
Cho a,b,c là 3 số thực dương thoả mãn a+b+c=1.CMR
\(\sqrt{a+bc}+\sqrt{b+ca}+\sqrt{c+ab}=1+\sqrt{bc}+\sqrt{ca}+\sqrt{ab}\)
Cho a,b,c >= 0
CMR a, a+b+c >= \(\sqrt{ab}+\sqrt{bc}+\sqrt{ca}\)
b, Cho a,b >0 Cm \(\sqrt{a}+\sqrt{b}< \frac{3}{\sqrt{a}}+\frac{a}{\sqrt{b}}\)
Cho a,b,c là 3 số thực dương TM a+b+c=1
CMR
\(\sqrt{a+bc}+\sqrt{b+ca}+\sqrt{c+ab}\ge1+\sqrt{bc}+\sqrt{ca}+\sqrt{ab}\)