lean_workbook_plus_42343

Proved

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

Let $a,b$ be positive numbers such that $ab=1.$ Prove that $a^2+b^2+4\geq 3(a+b)$

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_42343 (a b : ℝ) (hab : a * b = 1) : a ^ 2 + b ^ 2 + 4 ≥ 3 * (a + b)   :=  by sorry

Source