Problem

Source: 2021 Thailand October Camp 1.2

Tags: inequalities



Let $a,b,c>0$ satisfy $a\geq b\geq c$. Prove that $$\frac{4}{a^2(b+c)}+\frac{4}{b^2(c+a)}+\frac{4}{c^2(a+b)} \leq \left(\sum_{cyc} \frac{a^2+1} {b^2} \right)\left(\sum_{cyc} \frac{b^3}{a^2(a^3+2b^3)}\right).$$