l99 New member Xu 0 11/12/11 #1 Cho \[ a, b, c, ab+ bc+ ca= 1.\] và \[a, b, c> 0\] CMR: \[\frac{\sqrt{a^{2}+ 1}+ \sqrt{b^{2}+ 1}}{\sqrt{c^{2}+ 1}}+ \frac{\sqrt{b^{2}+ 1}+ \sqrt{c^{2}+ 1}}{\sqrt{a^{2}+ 1}}+ \frac{\sqrt{a^{2}+ 1}+ \sqrt{c^{2}+ 1}}{\sqrt{b^{2}+ 1}}\ge 2\sqrt{3}\]
Cho \[ a, b, c, ab+ bc+ ca= 1.\] và \[a, b, c> 0\] CMR: \[\frac{\sqrt{a^{2}+ 1}+ \sqrt{b^{2}+ 1}}{\sqrt{c^{2}+ 1}}+ \frac{\sqrt{b^{2}+ 1}+ \sqrt{c^{2}+ 1}}{\sqrt{a^{2}+ 1}}+ \frac{\sqrt{a^{2}+ 1}+ \sqrt{c^{2}+ 1}}{\sqrt{b^{2}+ 1}}\ge 2\sqrt{3}\]
L levietnam New member Xu 0 12/3/12 #3 De bai co van de vi:AD bat dang thuc co si cho 3 cap moi cap 2 so thi VP>=6 >2can3 luon