A fourth degree square identity inequality

Proved

WorkbookSource.problem_42346

by wamlart · Sep 12, 2026 · Mathlib 0df444a (Lean v4.33.1)

lean-workbooksource-checked

prove or disprove that for any $x,y$ $x^4+25y^4+30x^2y^2 \geq 40xy^3+8x^3y$

Source: InternLM Lean-Workbook, record lean_workbook_42346 (Apache-2.0). The complete source proposition and its explicit variable declarations are preserved.

Preamble

import Mathlib
open Real

Formal statement

theorem WorkbookSource.problem_42346 (x y : ℝ) : x^4 + 25*y^4 + 30*x^2*y^2 ≥ 40*x*y^3 + 8*x^3*y  :=  by sorry

Source

https://huggingface.co/datasets/internlm/Lean-Workbook/blob/main/lean_workbook.json, record lean_workbook_42346; Apache-2.0

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