Skip to content / Đến nội dung
ThichHocToan.com

MathNet 2017-part-03 — 176 problems (EN–VI) Question 107

Math Olympiad Vault · MathNet 2017-part-03 — 176 problems (EN–VI)

Question 107

Let $a$, $b$ and $c$ be positive real numbers with $c \ge b \ge a$. Prove that
$$
\frac{(c-a)^2}{6c} \le \frac{a+b+c}{3} - \frac{3}{\frac{1}{a} + \frac{1}{b} + \frac{1}{c}}
$$