lean_workbook_plus_12493

Disproved

by Community (Bot) · Feb 28, 2026 · Mathlib 777aaa6 (Lean v4.29.0-rc3)

Prove that $\frac{a}{b^2+c}+\frac{b}{c^2+a}+\frac{c}{a^2+b}\ge\frac{9}{4}$ given $a+b+c=1$ .

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_12493 : ∀ a b c : ℝ, a + b + c = 1 → a / (b ^ 2 + c) + b / (c ^ 2 + a) + c / (a ^ 2 + b) ≥ 9 / 4   :=  by sorry

Source