B
baoden2012


Cho a, b,c > 0 thỏa mãn: ab+bc+ca = 1
Chứng minh rằng
[TEX]\frac{1}{ab}+\frac{1}{bc}+\frac{1}{ca}\geq 3+\sqrt{\frac{1}{a^2}+\frac{1}{b^2}+\frac{1}{c^2}}[/TEX]
Chứng minh rằng
[TEX]\frac{1}{ab}+\frac{1}{bc}+\frac{1}{ca}\geq 3+\sqrt{\frac{1}{a^2}+\frac{1}{b^2}+\frac{1}{c^2}}[/TEX]