lean_workbook_plus_3670

Proved

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

Prove that for all positive real numbers $a$ and $b$ : $\frac{(a + b)^3}{4} \ge a^2b + ab^2$

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_3670 (a b : ℝ) (ha : 0 < a) (hb : 0 < b) : (a + b) ^ 3 / 4 ≥ a ^ 2 * b + a * b ^ 2   :=  by sorry

Source