Question 90
Let $a$, $b$, $c$ be positive real numbers such that $a^2 + b^2 + c^2 = 3$. Prove that
$$
\frac{1}{a} + \frac{3}{b} + \frac{5}{c} \geq 4a^2 + 3b^2 + 2c^2.
$$
$$
\frac{1}{a} + \frac{3}{b} + \frac{5}{c} \geq 4a^2 + 3b^2 + 2c^2.
$$
MathNet 2018-part-04 — 181 problems (EN–VI) Question 90
Math Olympiad Vault · MathNet 2018-part-04 — 181 problems (EN–VI)