1 Bất đẳng thức đồng bậc Mon Aug 16, 2010 12:20 pm
toanhocsinhvien.com
Cho $a,b,c \ge 0$. Chứng minh:
$\frac{a^2}{b^3+c^3}+\frac{b^2}{c^3+a^3}+\frac{c^2}{a^3+b^3} \ge \frac{3\sqrt{3}}{2\sqrt{a^2+b^2+c^2}}$
$\frac{a}{b^3+c^3} + \frac{b}{c^3+b^3} + \frac{c}{a^3+b^3} \ge \frac{3 \sqrt{3} }{2 \sqrt{a^4+b^4+c^4}}$
$\frac{a}{b^3+c^3} + \frac{b}{c^3+b^3} + \frac{c}{a^3+b^3} \ge \frac{3 \sqrt{3} }{2 \sqrt{a^4+b^4+c^4}}$