lean_workbook_plus_35525

Proved

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

Let $a$ be real number. Show that $(k+2)(1 + a^2 + ka^4)\geq (1 + a + ka^2)^2$ Where $k\ge 0.$

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_35525 (k : ℝ) (a : ℝ) (h : k ≥ 0) : (k + 2) * (1 + a ^ 2 + k * a ^ 4) ≥ (1 + a + k * a ^ 2) ^ 2   :=  by sorry

Source